• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention provides a chemical mechanical polishing (CMP) felt for polishing semiconductor or three-dimensional memory substrates comprising a polishing layer of a polyurethane reaction product of a thermosetting reaction mixture of a 4.4' hardener -methylenebis(3-chloro-2,6-diethyaniline) (MCDEA) or mixtures of MCDEA and 4,4'-methylene-bis-o-(2-chloroaniline) (MbOCA), and a polyisocyanate prepolymer formed from one or two aromatic diisocyanates, such as toluene diisocyanate (TDI), or a mixture of an aromatic diisocyanate and an alicyclic diisocyanate, and a polytetramethylene ether glycol (PTMEG) polyol , polypropylene glycol (PPG), or a polyol combination of PTMEG and PPG and having an unreacted isocyanate (NCO) concentration of 8.6 to 11% by weight. The polyurethane in the polishing layer has a Shore D hardness according to ASTM D2240-15 (2015) of 50 to 90, a storage shear modulus (G') at 65°C of 70 to 500 MPa, and a constituent of damping (G″/G′ measured by dynamic shear mechanical analysis (DMA), ASTM D5279-08 (2008)) at 50° C. from 0.06 to 0.13.
    公开号:FR3066940A1
    申请号:FR1854878
    申请日:2018-06-05
    公开日:2018-12-07
    发明作者:Jonathan G. Weis；Nan-Rong Chiou；George C. Jacob；Bainian Qian
    申请人:Rohm and Haas Electronic Materials CMP Holdings Inc；Dow Global Technologies LLC；
    IPC主号:
    专利说明:

    The present invention relates to chemical mechanical polishing felts and methods of using them. More particularly, the present invention relates to a chemical mechanical polishing felt having a low damping constituent comprising a polishing layer or upper polishing surface of a polyurethane reaction product of a thermosetting reaction mixture comprising a hardener of 4, 4'-methylenebis (3chloro-2,6-diethylaniline) (MCDEA) or mixtures of MCDEA and 4,4'methylene-bis-o- (2-chloroaniline) (MbOCA) and a polyisocyanate prepolymer formed at from a polytetramethylene ether glycol polyol (PTMEG), polypropylene glycol (PPG) or a combination of polyols of PTMEG and PPG and an aromatic diisocyanate or a combination of aromatic diisocyanate and alicyclic diisocyanate, and having a content of 8.6 to 11% by mass of unreacted isocyanate (NCO), and methods of using the felt to polish substrates of three-dimensional memories or of semiconductors, such as substrates of non-volatile flash memories (for example 3D NAND).
    In the production of any semiconductor or memory device, several chemical mechanical polishing processes (CMP polishing) may be necessary. In each CMP process, a polishing felt in combination with a polishing solution, such as a polishing suspension containing an abrasive or abrasive-free reagent liquid, removes excess material so that it planarizes or maintain a flatness of the substrate. The stacking of multiple layers in semiconductors combines in a way that forms an integrated circuit. The manufacturing of such semiconductor devices continues to be more complex due to the requirements for devices with higher operating speeds, lower leakage currents and reduced current consumption.
    The appearance of architectures of three-dimensional memories (for example, 3D-NAND) and cells or rows of dimensionally stacked memories has led to the need for CMP polishing of substrates having large lateral dimensions. Such substrates require planarization on the scale of the element or mold to lateral dimensions of, for example, 1-50 mm between elements which need to be planarized. In particular, 3D NAND memory substrates having at least a small surface of 1 to 5 mm in width have produced in particular new geometries for CMP polishing. Such geometries will include significantly thicker oxide films (> 1 µm) and wider side elements (1-10 mm) which require planarization to scale of the element. Thick oxide films impose an extraordinarily high removal speed requirement; and wide elements require a new class of CMP polishing felt materials capable of planarizing orders of magnitude of longer side lengths than prior CMP substrates.
    U.S. Patent Publication No. 2015/0059254 A1 in the name of Yeh et al. discloses polyurethane polishing felts which comprise the polyurethane reaction product of a polyurethane prepolymer from polypropylene glycol and toluene diisocyanate and 4,4'-methylenebis (3-chloro-2,6-diethylaniline) (MCDEA) as a hardener. The resulting CMP polishing felts allow improved polishing of metal-containing substrates but do not provide the removal rates necessary to effectively polish semiconductor or three-dimensional memory substrates having an oxide film of at least 1 µm thick and at least a small area of 1 to 5 mm in width.
    The present inventors sought to solve the problem of providing an efficient chemical mechanical polishing felt (CMP polishing) which provides the large scale removal and planarization speeds necessary for polishing semiconductor substrates or three-dimensional memories, such as as non-volatile flash memory substrates (3D NAND).
    STATEMENT OF THE INVENTION
    1. According to a first aspect, the present invention relates to mechanical chemical polishing felts (CMP) having a low damping constituent for polishing a substrate chosen from at least one of a three-dimensional memory and of a semiconductor substrate comprising a polishing layer suitable for polishing the substrate which is a polyurethane reaction product of a thermosetting reaction mixture comprising a hardener of 4,4'-methylenebis (3chloro-2,6-diethylaniline) (MCDEA) or mixtures of MCDEA and of 4,4'methylene-bis-o- (2-chloroaniline) (MbOCA) in a mass ratio of MCDEA to MbCOA of 3: 7 to 1: 0 or, preferably, of 4: 6 to 1: 0, and a polyisocyanate prepolymer having an unreacted isocyanate (NCO) concentration of 8.6 to 11% by mass, or preferably
    8.6 to 10.3% by mass of the polyisocyanate prepolymer and formed from one or two aromatic diisocyanates, such as chosen from diphenylmethylene diisocyanate (MDI); toluene diisocyanate (TDI); napthalene diisocyanate (NDI); para-phenylene diisocyanate (PPDI); or o-toluidine diisocyanate (TODI); a modified diphenylmethane diisocyanate, such as a carbodiimide modified diphenylmethane diisocyanate, an allophanate modified diphenylmethane diisocyanate, a biuret modified diphenylmethane diisocyanate; or an aromatic isocyanurate from a diisocyanate, such as MDI isocyanurate, preferably toluene diisocyanate (TDI) or a mixture of TDI and up to 20% by mass of MDI, based on the mass total of aromatic diisocyanates; or one or two aromatic diisocyanates, preferably TDI or TDI and up to 20% by mass of MDI, based on the total mass of aromatic diisocyanates, mixed with up to 67% by mass, or preferably, 64 , 5% by mass or less of an alicyclic diisocyanate, such as 4,4'-methylenebis (cyclohexylisocyanate) (H12-MDI), based on the total mass of aromatic and alicyclic diisocyanates; and a polytetramethylene ether glycol polyol (PTMEG), polypropylene glycol (PPG), or a combination of PTMEG and PPG polyols as reactants, wherein the polyurethane reaction product in the polishing layer has a hardness Shore D (2 seconds) according to ASTM D224015 (2015) from 50 to 90, or, preferably from 60 to 90 or from 70 to 80 and, moreover, in which the polyurethane reaction product in the polishing layer has a modulus in storage shear (G ') at 65 ° C from 70 to 500 MPa, or, preferably from 125 to 500 MPa, or, preferably, up to 260 MPa.
    2. According to a particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in point 1, above, the stoichiometric ratio of the sum of all the moles of amine groups (NH 2 ) and of all the moles of the hydroxyl groups (OH) in the reaction mixture relative to the totality of the moles of the unreacted isocyanate groups (NCO) in the reaction mixture is from 0.85: 1 to 1.20: 1 , or, preferably, from 1.00: 1 to 1.10: 1.
    3. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1 or 2, above, the polyol used to form the polyisocyanate prepolymer is chosen from (i) PTMEG, (ii) PPG or (iii) a combination of polyols of PTMEG and PPG in a ratio of PTMEG to PPG from 1: 0 to 1: 4, or, for example, from 12: 1 to 1: 1 .
    4. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1, 2 or 3 above, the mass average molecular mass (GPC) of the PTMEG in the polyol or combination of polyols is 800 to 1,600, or preferably 1,100 to 1,500.
    5. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1, 2, 3 or 4 above, the polishing layer of the CMP polishing felt further comprises microelements selected from trapped gas bubbles, polymeric hollow core materials, such as polymeric microspheres, polymeric hollow core liquid filled materials, such as fluid filled polymeric microspheres and, fillers, such as boron nitride, preferably, polymeric microspheres filled with expanded fluid.
    6. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in point 5, above, the amount of the microelements is from 0.4 to 2.5% by mass or, preferably from 0.75 to 2.0% by mass of one or more microelements, based on the total mass of the reaction mixture.
    7. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 5 or 6, above, the polishing felt or the polishing layer has a density from 0.55 to 1.17 g / cm 3 or, preferably, from 0.70 to 1.08 g / cm 3 .
    8. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 5, 6 or 7, above, the polishing felt or the polishing layer present a porosity of 0.01 to 53% or, preferably, 8 to 40%.
    9. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1, 2, 3, 4, 5, 6, 7 or 8, above, the polishing layer comprises a polyurethane reaction product having a hard segment of 45 to 70%; or preferably, from 50 to 70% based on the total mass of the thermosetting reaction mixture.
    10. According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1, 2, 3, 4, 5, 6, 7, 8 or 9, ci- above, the polishing layer has a damping component (G / G 'measured by dynamic mechanical shear analysis (DMA), ASTM D5279-08 (2008)) at 50 ° C from 0.06 to 0.13 or, preferably from 0.068 to 0.118.
    11. In another aspect, the present invention provides methods of polishing a substrate, comprising: providing a substrate selected from at least one of a magnetic substrate, an optical substrate and a substrate semiconductor; the supply of a chemical mechanical polishing felt (CMP) according to any one of points 1 to
    10, above; providing an abrasive polishing medium; creating dynamic contact between a polishing surface of the polishing layer of the CMP polishing felt, the abrasive polishing medium and the substrate to polish a surface of the substrate at a downward force of 103 to 550 hPa (1.5 to 8 psi); and conditioning the polishing surface of the polishing felt with an abrasive conditioner.
    12. According to a particular characteristic, in the chemical mechanical polishing processes of the present invention as defined in point 11, above, the substrate comprises a semiconductor or three-dimensional memory substrate, such as, for example, a 3D NAND memory.
    13. According to another particular characteristic, in the chemical mechanical polishing methods of the present invention as defined in point 12, above, the semiconductor or three-dimensional memory substrate comprises an oxide film of thickness d 'at least 1 µm or, preferably, 1 to 7 µm thick or, more preferably, 1 to 4 µm thick and has at least a small area 1 to 5 mm wide.
    14. According to another particular characteristic, in the chemical mechanical polishing processes of the present invention as defined in any one of points 12 or 13, above, the creation of dynamic contact results in a withdrawal speed d '' at least 8000 Â / minute or, preferably, at least 10 000 Â / minute.
    15. According to another particular characteristic, in the chemical mechanical polishing processes of the present invention as defined in any one of points 12, 13 or 14, above, the creation of dynamic contact includes the provision of an abrasive polishing medium, such as cerium oxide, having a total content of abrasive solids of 0.5 to 7% by mass and polishing at a downward force of 103 to 550 hPa (1.5 to 8 psi) , or preferably 206 to 483 hPa (3 to 7 psi) with the abrasive polishing medium.
    16. According to another particular characteristic, in the chemical mechanical polishing processes of the present invention as defined in point 15, above, the creation of dynamic contact comprises the supply of the abrasive polishing medium with an abrasive content. from 0.5 to 1.999% by mass or, preferably, from 0.5 to 1.5% by mass and polishing with a downward force of 206 to 550 hPa (3 to 8 psi), or, preferably, from 275 to 483 hPa (4 to 7 psi).
    17. According to another particular characteristic, in the chemical mechanical polishing methods of the present invention as defined in point 15, above, the creation of dynamic contact comprises the supply of the abrasive polishing medium with an abrasive content. from 2 to 6% by mass or, preferably, from 2.5 to 5.5% by mass and polishing with a downward force (DF) of 103 to 344 hPa (1.5 to 5 psi) or, preferably , from 137 to 344 hPa (2 to 5 psi).
    More particularly, the present invention relates to the following aspects:
    1) The present invention relates to a mechanochemical polishing felt (CMP) having a low damping constituent for polishing a substrate chosen from at least one of a memory and a semiconductor substrate comprising: a polishing layer suitable for polishing the substrate which is a polyurethane reaction product of a thermosetting reaction mixture comprising a hardener of 4,4'methyleneethylene (3-chloro-2,6-diethyaniline) (MCDEA) or mixtures of MCDEA and 4,4'- methylene-bis-o- (2-chloroaniline) (MbOCA) in a mass ratio of MCDEA to MbOCA of 3: 7 to 1: 0, and of a polyisocyanate prepolymer having an isocyanate (NCO) concentration having no reacted from 8.6 to 11% by mass and formed from one or two aromatic diisocyanates or from a mixture of an aromatic diisocyanate and up to 67% by mass of an alicyclic diisocyanate, based on the total mass aromatic and alicyclic diisocyanates, and a polytetr polyol amethylene ether glycol (PTMEG), polypropylene glycol (PPG), or a combination of polyols of PTMEG and PPG as reactants, characterized in that the polyurethane reaction product in the polishing layer has a Shore D hardness according to ASTM D2240-15 (2015) from 50 to 90, the polyurethane reaction product in the polishing layer has a shear modulus on storage (G 1 ) at 65 ° C from 70 to 500 MPa, and, the polishing layer has a damping component (G / G 'measured by dynamic mechanical shear analysis (DMA), ASTM D5279-08 (2008)) at 50 ° C from 0.06 to 0.13.
    2) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in point 1), above, the hardener comprises a mixture of MCDEA and 4,4'-methylene-bis -o- (2-chloroaniline) (MbOCA) in a mass ratio of MCDEA to MbOCA of 4: 6 to 1: 0.
    3) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in point 1) or 2), above, the aromatic diisocyanate or mixture of this with an alicyclic diisocyanate is chosen from toluene diisocyanate (TDI), TDI mixed with up to 20% by mass, based on the total mass of aromatic diisocyanate, diphenylmethylene diisocyanate (MDI), or a mixture of TDI and up to 67% by mass Hi 2 MDI, based on the total mass of aromatic and alicyclic diisocyanates.
    4) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 3), above, the polyisocyanate prepolymer has an isocyanate concentration ( NCO) having reacted from 8.6 to 10.3% by mass of the polyisocyanate prepolymer, and the polyol used to form the polyisocyanate prepolymer is chosen from (i) PTMEG, (ii) PPG or (iii) a combination of PTMEG and PPG polyols in a PTMEG to PPG ratio of 1: 0 to 1: 4 or 12: 1 to 1: 1.
    5) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 4), above, the stoichiometric ratio of the sum of all of the moles of amine groups (NH 2 ) and all of the moles of hydroxyl groups (OH) in the reaction mixture to all of the unreacted isocyanate (NCO) moles in the reaction mixture is 0.90: 1 to 1.20: 1.
    6) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 5), above, the polishing layer of the CMP polishing felt comprises more microelements chosen from trapped gas bubbles, polymeric materials with hollow cores, polymeric materials with hollow cores charged with liquid, and fillers.
    7) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 6), above, the reaction product of polyurethane in the polishing layer has a Shore D hardness according to ASTM D2240-15 (2015) from 60 to 90 and a storage shear modulus (G ') at 65 ° C from 125 to 500 MPa.
    8) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 7), above, the polishing felt or the polishing layer present a density of 0.55 to 1.17 g / cm 3 .
    9) According to another particular characteristic, in the chemical mechanical polishing felt of the present invention as defined in any one of points 1) to 8), above, the polishing layer comprises a reaction product of polyurethane having a hard segment of 45 to 70%, based on the total mass of the thermosetting reaction mixture.
    10) In another aspect, the present invention also relates to chemical mechanical polishing (CMP) methods of a substrate, comprising: the supply of a substrate chosen from at least one of a three-dimensional semiconductor or of a substrate from memory; the supply of a chemical mechanical polishing felt (CMP) according to any one of points 1) to 9), above; providing an abrasive polishing medium; and creating dynamic contact between a polishing surface of the polishing layer of the CMP polishing felt, the abrasive polishing medium and the substrate for polishing a surface of the substrate at a falling force (DF) of 103 to 550 hPa (1 , 5 to 8 psi); and conditioning the polishing surface of the polishing felt with an abrasive conditioner.
    Unless otherwise specified, the temperature and pressure conditions are room or room temperature and atmospheric pressure. All the ranges mentioned are inclusive and combinable.
    Unless otherwise indicated, any term containing parentheses refers, alternatively, to the entire term as if no parenthesis were present and to the term without them, and to combinations of each alternative. The term (poly) isocyanate thus refers to isocyanate, polyisocyanate, or mixtures thereof.
    All intervals are inclusive and combinable. The term an interval of 50 to 3000 cPs, or 100 cPs or more would for example each include 50 to 100 cPs, 50 to 3000 cPs and 100 to 3000 cPs.
    As used herein, the term ASTM refers to publications by ASTM International, West Conshohocken, PA.
    As used here, the terms G 1 , G and G / G '(which corresponds to tan delta), refer respectively to the shear modulus on storage, shear loss module, and to the ratio of the shear loss module to the module in shear during storage. Test samples were cut to a width of 6.5 mm and a length of 36 mm. An ARES ™ G2 torsion rheometer or a Rheometric Scientific ™ RDA3 (both from TA Instruments, New Castle, DE) was used according to ASTM D5279-13 (2013), Standard Test Method for Plastics: Dynamic Mechanical Properties: In Torsion ( Standard Test Method for Plastics: Dynamic Mechanical Properties: In Twist). The space separation was 20 mm. The instrument analysis parameters were set to 100 g of preload, 0.2% of stress, oscillation speed of 10 rad / s, and temperature ramp rate of 3 ° C / min from -100 ° C to 150 ° C.
    As used herein, the term molecular weight or GPC, unless otherwise indicated, indicates the result determined by gel permeation chromatography of an analyte polyol (GPC) against standards of polyether polyol or polyglycol, for example PEG.
    As used herein, the term hard segment of a polyurethane reaction product or raw material from the thermosetting reaction mixture refers to that portion of the reaction mixture indicated which includes any diol, glycol, diglycol, diamine, triamine or polyamine, diisocyanate, tri isocyanate, or reaction product thereof. The hard segment thus excludes polyethers or polyglycols having three or more ether groups, such as polytetramethylene glycols or polypropylene polyglycols.
    As used herein, the term PPG refers to any of poly (propylene glycol), PPG initiated by ethylene oxide (EO) and PPG extended by (di) ethylene glycol.
    As used herein, the term polyisocyanate indicates any isocyanate group containing a molecule having three or more isocyanate groups, including block isocyanate groups.
    As used herein, the term polyisocyanate prepolymer indicates any isocyanate group containing a molecule which is the reaction product of an excess of a diisocyanate or polyisocyanate with a compound containing active hydrogen containing two or more active hydrogen groups, such as as diamines, diols, triols, and polyols.
    As used herein, the term polyurethanes refers to products of polymerization from difunctional or polyfunctional isocyanates, for example polyetherureas, polyisocyanurates, polyurethanes, polyureas, polyurethanes, copolymers thereof, and mixtures thereof.
    As used herein, the term reaction mixture includes any non-reactive additive, such as microelements or additives to stimulate modulus or flexural stiffness, such as boron nitride or a polymeric polyacid, such as poly (methacrylic acid) ) or salts thereof.
    As used here, the term SG or specific gravity refers to the mass / volume ratio of a rectangular cut of a felt or of a polishing layer according to the present invention.
    As used herein, the term Shore D hardness is the hardness at 2 seconds of a given material as measured according to ASTM D2240-15 (2015), Standard Test Method for Rubber Property-Durometer Hardness Durometer hardness). Hardness was measured on a Rex Hybrid hardness tester (Rex Gauge Company, Inc., Buffalo Grave, IL), equipped with a D probe. Six samples were stacked and mixed for each hardness measurement; and each felt felt was conditioned by placing it in a relative humidity of 50 percent for five days at 23 ° C before the test and using the methodology cited in ASTM D2240-15 (2015) to improve the repeatability of the hardness tests. The Shore D hardness of the polyurethane reaction product of the polishing layer or felt includes in the present invention the Shore D hardness of this reaction product.
    As used herein, the term solids refers to the materials which remain in the polyurethane reaction product of the present invention; the solids thus include reactive and non-volatile additives which do not volatilize during hardening. Solids exclude water, ammonia and volatile solvents.
    As used herein, the term step height refers to the maximum difference in film height between the top and bottom surface of the element to be polished in a semiconductor or three-dimensional memory substrate.
    As used herein, the term stoichiometry of a reaction mixture refers to the ratio of molar equivalents of (free OH groups + free NH 2 ) to free NCO groups in the reaction mixture.
    As used herein, unless otherwise indicated, the term substantially free of water indicates that a given composition has no added water and that the materials included in the composition have no added water. A reaction mixture which is substantially free of water may comprise water which is present in the raw materials, in the range of 50 to 2,000 ppm or, preferably, 50 to 1,000 ppm, or may comprise the reaction water formed in a condensation reaction or steam from the ambient humidity in which the reaction mixture is used.
    As used here, the term conditions of use indicates the temperature and the pressure at which a CMP polishing of a substrate is carried out, or at which the polishing takes place.
    As used herein, unless otherwise noted, the term viscosity refers to the viscosity of a given material in an undiluted form (100%) at a given temperature as measured using a rheometer, set to an oscillatory shear speed sweep 0.1-100 rad / s in a geometry of parallel plates of 50 mm with a space of 100 pm.
    As used herein, unless otherwise indicated, the term number average molecular weight or Mn and mass average molecular weight or Mw indicates the value determined by gel permeation chromatography (GPC) at room temperature using a high pressure liquid chromatogram (HPLC ) Agilent 1100 (Agilent, Santa Clara, CA) equipped with an isocratic pump, an autosampler (injection volume (50 pl) and a series of 4 PL-Gel ™ columns (7 mm x 30 mm x 5 pm), each filled with a divinylbenzene polystyrene gel (PS / DVB) in a succession of pore sizes of 50, 100, 500 and then 1000 Å compared to a standard calibrated from a mixture of polyols (1.5% by mass in THF) of polyethylene glycols and polypropylenes glycols as standards For the polyisocyanate prepolymers, the isocyanate functional groups (N = C = O) of the isocyanate samples were converted with methanol from of a dried solution of methanol / THF to non-reactive methyl carbamates.
    As used herein, unless otherwise indicated, the term% by mass of NCO refers to the amount of unreacted or free isocyanate groups in a given polyisocyanate prepolymer composition.
    As used herein, the term% by mass represents one percent by mass.
    According to the present invention, a mechanochemical polishing felt (CMP) has an upper polishing surface comprising the reaction product of a reaction mixture of a hardener of 4,4 'methylenebis (3-chloro-2 z 6-diethylaniline) (MCDEA) or MCDEA mixed with 4,4'-methylene-bis-o- (2-chloroaniline) (MbOCA) and a polyisocyanate prepolymer formed from a polytetramethylene ether glycol polyol (PTMEG), polypropylene glycol (PPG) or a mixture of polyols of PTMEG and PPG. The polishing layer according to the present invention retains a shear modulus at favorable storage, measured by G ′, and a component of low damping (from 0.06 to 0.13) in a temperature regime of the polishing used (c 'ie, G / G' measured by dynamic mechanical shear analysis (DMA), ASTM D5279-08 (2008)). The uncharged polishing layer material of the present invention also has a high tensile modulus (> 400 MPa). The high storage shear modulus and low damping coefficient allow the CMP polishing layer to provide the high shrinkage speed and excellent planarization at the long length scale required for semiconductor or three-dimensional memory substrates, such as non-volatile flash memory substrates (3D NAND). In long-scale scaling, the CMP polishing layer of the present invention polishes semiconductor or three-dimensional memory substrates having at least a small area having a width of 1 mm or more, such as from 1 to 5 mm.
    The CMP polishing layers of the CMP polishing felts of the present invention are porous felt materials with a significantly high modulus at the temperatures used and a high flexural rigidity. These properties are achieved by using 4,4'-methylenebis (3-chloro-2,6-diethylaniline) (MCDEA) as the hardener or at least 30% by mass, or, preferably, at least 40% by mass of the diamine hardener mixture used in the thermosetting reaction mixture of the present invention. The addition of MCDEA to a hardener mixture improves long-term planarization by increasing the modulus (shear modulus during storage) and by maintaining an appropriate tan delta (damping component) under the conditions of use. For a given porosity, CMP polishing layers with a higher modulus have improved flexural stiffness, which contributes to improved planarization ability on scales of longer length (> 3 mm). In addition, a higher modulus at the surface polishing temperatures of the substrate used typically corresponds to a higher withdrawal speed (RR). Compared with flexural stiffness, a higher tan delta or damping component can also improve planarization, even to a greater extent on a shorter length scale (<1 mm). In the intermediate regime (1-5 mm), it may appear that the two parameters contribute to the ability to planarize and that tan delta may be lower than that in the shorter scale scale regime. The CMP temperature or polishing regime may not overlap the measurement temperature of a given material property since the measured disc temperatures may not adequately reflect the roughness temperatures in the polishing layer; furthermore, the polishing layer material is subjected to varying deformation rates during the polishing operation.
    The chemical mechanical polishing felts of the present invention comprise a polishing layer which is a homogeneous dispersion of microelements in a porous polyurethane or a homogeneous polyurethane. Homogeneity is important to achieve consistent performance of the polishing felt, especially when a single cast is used to make multiple polishing felts. The reaction mixture of the present invention is therefore chosen so that the resulting felt morphology is stable and easily reproducible. For example, it is often important to control additives, such as antioxidants, and impurities, such as water for consistent manufacturing. As water reacts with isocyanate to form carbon dioxide gas and a weak reaction product compared to urethanes in general, the water concentration can affect the concentration of carbon dioxide bubbles which form pores in the matrix as well as the overall consistency of the polyurethane reaction product. The reaction of isocyanate with incident water also reduces the isocyanate available to react with a chain extender, thereby changing the stoichiometry with the level of crosslinking (if there is an excess of isocyanate groups) and tends to lower the molecular weight of the resulting polymer.
    The porosity of the CMP polishing layer of the present invention can be between 0 and 53% or, preferably, from 8 to 40%, for example, from 12 to 25%. The polishing layer is more easily conditioned to a higher porosity, but provides better rigidity and planarization on the long length scale at a lower porosity.
    In order to ensure homogeneity and good molding results and to fill the mold completely, the reaction mixture of the present invention must be well dispersed.
    A reaction mixture according to the present invention comprises on the one hand, at least one polyisocyanate prepolymer consisting of aromatic diisocyanate, for example, toluene diisocyanate, and of the polyol component and, on the other hand, of 4.4 '-methyleneene (3-chloro2,6-diethylaniline) (MCDEA) or MCDEA with 4,4'-methylene-bis-o- (2chloroaniline) (MbOCA).
    The polymeric material or polyurethane reaction product is preferably formed from, on the one hand, a reaction product of a polyisocyanate of aromatic diisocyanates prepolymer, such as toluene diiosocyanate (TDI), with a polytetramethylene polyol ether glycol (PTMEG), polypropylene glycol (PPG) or PTMEG mixed with PPG and hardener.
    The aromatic diisocyanate or aromatic and alicyclic diisocyanate partially reacts with the combination of polyols to form a polyisocyanate prepolymer before the production of the final polymer matrix.
    The polyisocyanate prepolymer may further be combined with diphenylmethylene diisocyanate (MDI), or MDI elongated with a diol or polyether or it may further be the reaction product of aromatic diisocyanate, polyol and MDI or elongated MDI, where MDI is present in the amount of 0.05 to 20% by mass, or, for example, up to 15% by mass or, for example, from 0.1 to 12% by mass, based on the total mass of aromatic diisocyanates used to make the polyisocyanate prepolymer.
    The polyisocyanate prepolymer can also be combined with methylene-bis-cyclohexyl diisocyanate (Hi 2 MDI), or H12-MDI extended by a diol or polyether, or it can also be the product of the aromatic diisocyanate, polyol and H12-MDI or elongated H12-MDI, where H12-MDI is present in the amount of 0.05 to 60% by mass, or, for example, up to 53% by mass or, for example, 0.1 to 53% by mass, based on the total mass of the aromatic and alicyclic diisocyanate used to manufacture the polyisocyanate prepolymer. This combination can also be combined or react with from 0.05 to 20% by mass, or, for example, up to 15% by mass or, for example, from 0.1 to 12% by mass of MDI, based on the total mass of aromatic diisocyanates used to make the polyisocyanate prepolymer.
    For clarity, the mass of MDI or H12-MDI in the case of an MDI or H12-MDI extended by a diol or polyether is considered to be the mass fraction of MDI or H12-MDI itself in the MDI or H12-MDI elongated.
    For the purpose of this description, the formulations are expressed in% by mass, unless otherwise indicated.
    The polyisocyanate prepolymer of the present invention is the reaction product of a mixture containing the aromatic diisocyanate and a total of 30 to 66% by mass or, preferably, 43 to 62% by mass, such as 45 to less 62% by mass, of the mixture of polyols (PPG and PTMEG), based on the total mass of reactants used to manufacture the prepolymer. The rest of the reaction mixture includes the hardener.
    The polishing layer of the present invention is formed from a reaction mixture of the polyisocyanate prepolymer and the hardener, wherein the amount of the hardener is 23 to 33% by mass, or preferably 24 to 30% by mass, based on the total mass of the reaction mixture.
    A suitable polyisocyanate prepolymer is preferably formed from a mixture of toluene diisocyanate (TDI), i.e. as a partially reacted monomer, in the amount of 16 to 46% by mass, or, preferably more than 20 to 45% by mass. For the purpose of this description, the TDI monomer or the partially reacted monomer represents the% by mass of TDI monomer or of TDI monomer which reacted in a prepolymer before the curing of the polyurethane and does not include the other reactants which form the partially reacted monomer. The TDI portion of the mixture may optionally also contain a certain amount of aliphatic isocyanate. The diisocyanate component preferably contains less than 15% by mass of aliphatic isocyanates and better still less than 12% by mass of aliphatic isocyanates. The mixture preferably contains only contents of impurities of aliphatic isocyanates. For clarity, an alicyclic diisocyanate is not considered to be an aliphatic isocyanate.
    Available examples of polyols containing PTMEG are the following: Térathane ™ 2900, 2000, 1800, 1400, 1000, 650 and 250 from Invista, Wichita, KS; Polymeg ™, 2900, 2000, 1000, 650 from Lyondell Chemicals, Limerick, PA; PolyTHF ™ 650, 1000, 2000 from BASF Corporation, Florham Park, NJ. Available examples of polyols containing PPG are: Arcol ™ PPG-425, 725, 1000, 1025, 2000, 2025, 3025 and 4000 from Covestro, Pittsburgh, PA; Voranol ™ 1010L, 2000L, and P400 from Dow, Midland, MI; Desmophen ™ 1110BD or Acclaim ™ Polyol 12200, 8200, 6300, 4200, 2200, each from Covestro.
    Examples of commercially available isocyanate-terminated urethane prepolymers containing PPG include the prepolymers Adiprene ™ (Chemtura), such as LFG 963A, LFG 964A,
    LFG 740D; Andur ™ prepolymers (Anderson Development Company,
    Adrian, MI), such as 7000 AP, 8000 AP, 6500 DP, 9500 APLF, 7501, or
    DPLF. Examples of suitable PPG prepolymers include the Adiprene ™ LFG740D and LFG963A prepolymers.
    A catalyst can be used to increase the reactivity of a polyol with a diisocyanate or polyisocyanate to make a polyisocyanate prepolymer. Suitable catalysts include, for example, oleic acid, azelaic acid, dibutyltin dilaurate, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), tertiary amine catalysts, such as Dabco TMR, and mixtures of those above.
    A suitable polyisocyanate prepolymer of the present invention has a viscosity in an undiluted form of 10,000 mPa.s or less than 110 ° C or, preferably, from 20 to 5,000 mPa.s.
    Examples of suitable commercially available isocyanate-terminated urethane prepolymers containing PTMEG include Imuthane ™ prepolymers (available from COIN USA, Inc., West Deptford, NJ), such as PET-80A, PET-85A, PET-90A , PET-93A, PET-95A, PET-60D, PET-70D, or PET-75D; Adiprene ™ prepolymers (Chemtura, Philadelphia, PA), such as, for example, LF 800A, LF 900A, LF 910A, LF930A, LF931A, LF 939A, LF 950A, LF 952A, LF 600D, LF 601D, LF 650D, LF 667, LF 700D, LF 750D, LF 751D, LF 752D, LF 753D or L 325); Andur ™ prepolymers (Anderson Development Company, Adrian, MI), such as, 70APLF, 80APLF, 85APLF, 90APLF, 95APLF, 60DPLF, 70APLF, or 75APLF.
    The polyisocyanate prepolymers of the present invention may also be aromatic isocyanate prepolymers of low free aromatic isocyanate content which have less than 0.1% by mass of each of the monomers 2.4 and 2.6 free TDI and have a more consistent molecular weight distribution of prepolymer than conventional prepolymers. Low content free aromatic isocyanate prepolymers with an improved prepolymer molecular weight consistency and a low free isocyanate monomer content facilitate a more regular polymer structure, and contribute to an improved consistency of the polishing felt.
    The polyurethane used in the formation of the polishing layer of the chemical mechanical polishing felt of the present invention is preferably an isocyanate terminated urethane of low free form content having a lower free toluene diisocyanate (TDI) monomer content. at 0.1% by mass.
    In order to ensure that the resulting felt morphology is stable and easily reproducible, it is often important for example to control additives, such as antioxidants, and impurities, such as water for consistent manufacturing. For example, as water reacts with the isocyanate to form carbon dioxide gas, the concentration of water can affect the concentration of carbon dioxide bubbles that form pores in the polymer matrix. The reaction of isocyanate with incident water also reduces the isocyanate available for reaction with polyamine so that it modifies the molar ratio of OH or NH 2 groups to NCO with the level of crosslinking (if there is has an excess of isocyanate groups) and the molecular weight of the resulting polymer.
    In the reaction mixture of the present invention, the stoichiometric ratio of the sum of the total amine groups (NH 2 ) and the total of hydroxyl groups (OH) in the reaction mixture to the sum of the isocyanate groups (NCO) having no reacted in the reaction mixture is 0.85: 1 to 1.2: 1, or preferably 1.0: 1 to 1.1: 1.
    The reaction mixture of the present invention is free of added organic solvents.
    The reaction mixture of the present invention is preferably substantially free of water (less than 2000 ppm), based on the total mass of the reaction mixture.
    According to the methods of manufacturing the polishing layer of the present invention, the methods include providing the polyisocyanate prepolymer of the present invention at a temperature of 45 to 65 ° C, cooling the prepolymer to 20 to 40 ° C, or preferably, from 20 to 30 ° C; providing a hardener and forming the thermosetting reaction mixture of the polyisocyanate prepolymer, and, if desired, of a microelement material as a component and of the hardener as another component, preheating a mold to from 60 to 100 ° C, or preferably 65 to 95 ° C, filling the mold with the reaction mixture and thermosetting the reaction mixture at a temperature of 80 to 120 ° C over a period of 4 to 24 hours, or, preferably 6 to 16 hours to form a molded polyurethane reaction product.
    The methods of forming the polishing layer of the present invention further include slicing or splitting the molded polyurethane reaction product to form a layer having a thickness of 0.5 to 10 mm, or preferably 1 at 3 mm.
    The methods of making the polishing layer of the present invention allow the manufacture of a low porosity felt from a reaction mixture which provides a substantial exothermic reaction and unusually hardens and is a hard molded polyurethane reaction product. . Cooling the polyisocyanate prepolymer component and preheating the mold prevents the mold or cake from bursting, where the hardened or cast material unmolds from the base and cannot be sliced or split to form a polishing layer. In addition, the methods of manufacturing a CMP polishing felt of the present invention avoid heterogeneous secondary expansion of microelements and limit the variability of SG in the resulting mold or cake, thereby increasing the yield of polishing layers from mold or cake after splitting or slicing.
    The chemical mechanical polishing felts of the present invention can comprise just a polishing layer of the polyurethane reaction product or the polishing layer stacked on an under felt or an under layer. The polishing felt or, in the case of stacked felts, the polishing layer of the polishing felt of the present invention is useful in both porous and non-porous or uncharged configurations. Regardless of whether it is porous or non-porous, the polishing felt or the finished polishing layer (in a stacked felt) preferably has a density of 0.7 to 1.20 g / cm 3 or, even better, from 0.9 to 1.08 g / cm 3 . It is possible to add porosity by dissolution of gases, blowing agents, mechanical foaming and introduction of hollow microspheres. The density of the polishing felt is as measured according to ASTM D1622-08 (2008). Density is closely correlated within 1-2% of specific gravity.
    The porosity of the polishing layer of the present invention typically has an average diameter of 2 to 50 µm. The porosity comes even better from hollow polymer particles having a spherical shape. The hollow polymer particles preferably have a mass average diameter of 2 to 40 µm. For the purpose of this description, the mass average diameter represents the diameter of the hollow polymer particle before casting; and the particles can have a spherical or non-spherical shape. The hollow polymer particles even better have a mass average diameter of 10 to 30 μm.
    The polishing layer of the mechanochemical polishing felt of the present invention optionally further comprises micro-elements which, preferably, are uniformly dispersed from one end to the other of the polishing layer. Such microelements, particularly hollow spheres, can expand during casting. The microelements can be chosen from trapped gas bubbles, polymeric materials with hollow cores, such as polymeric microspheres, polymeric materials with hollow cores charged with liquid, such as polymeric microspheres charged with fluid, materials soluble in water, an insoluble phase material (for example mineral oil), and fillers of abrasives, such as boron nitride. The microelements are preferably chosen from bubbles of trapped gas and polymeric materials with hollow cores uniformly distributed from one end to the other of the polishing layer. The microelements have a mass average diameter of less than 100 µm (preferably 5 to 50 µm). The several microelements even better comprise polymeric microspheres with walls of envelopes either of polyacrylonitrile or of a polyacrylonitrile copolymer (for example Expancel ™ beads from Akzo Nobel, Amsterdam, Netherlands).
    According to the present invention, the microelements are incorporated in the polishing layer at from 0.4 to 5.5% by mass of porogen, or, preferably from 0.75 to 5.0% by mass.
    The polyurethane reaction product of the polishing layer of the chemical mechanical polishing felt of the present invention has a Shore D hardness of 50 to 90 as measured according to ASTM D2240-15 (2015).
    The polishing layer used in the chemical mechanical polishing felt of the present invention preferably has an average thickness of 500 to 3,750 microns (20 to 150 mils), or, even better, 750 to 3,150 microns (30 to 125 mils), or even better still from 1000 to 3000 microns (40 to 120 mils), or, particularly preferably from 1250 to 2500 microns (50 to 100 mils).
    The chemical mechanical polishing felt of the present invention optionally further comprises at least one additional layer interfaced with the polishing layer. Preferably, the chemical mechanical polishing felt optionally further comprises an under-felt or a compressible base layer bonded to the polishing layer. The compressible base layer preferably improves the conformity of the polishing layer to the surface of the substrate which is polished.
    The polishing layer of the mechanochemical polishing felt of the present invention has a polishing surface suitable for polishing the substrate. The polishing surface preferably has a macrotexture chosen from at least one of perforations and grooves. The perforations may extend from the polishing surface in part or over the whole through the thickness of the polishing layer.
    Grooves are preferably arranged on the polishing surface such that during rotation of the chemical mechanical polishing felt during polishing, at least one groove scans the surface of the substrate which is polished.
    The polishing surface preferably has a macrotexture including at least one groove chosen from the group consisting of curved grooves, linear grooves, perforations and combinations thereof.
    The polishing layer of the mechanochemical polishing felt of the present invention preferably has a polishing surface suitable for polishing the substrate, wherein the polishing surface has a macrotexture comprising a pattern of grooves formed therein. The groove pattern preferably includes multiple grooves. The pattern of grooves is even better chosen from a configuration of grooves, such as one chosen from the group consisting of concentric grooves (which may be circular or helical), curved grooves, hatched grooves (for example arranged as an XY grid through felt surface), other regular patterns (e.g. hexagons, triangles), tire tread patterns, irregular patterns (e.g. fractal patterns), and combinations thereof. The groove configuration is even better chosen from the group consisting of random grooves, concentric grooves, helical grooves, hatched grooves, X-Y grid grooves, hexagonal grooves, triangular grooves, fractal grooves and combinations thereof. The polishing surface has an even better pattern of helical grooves formed therein. The groove profile is preferably chosen from a rectangular profile with linear side walls or the cross section of grooves can be V-shaped, U-shaped, sawtooth, and combinations thereof.
    The methods of making a mechanochemical polishing felt of the present invention may include providing a mold; pouring the reaction mixture of the present invention into the mold; and, allowing the combination to react in the mold to form a cured cake, in which the polishing layer is derived from the cured cake. The cured cake is preferably sliced to produce multiple polishing layers from a single cured cake. The method optionally further comprises heating the hardened cake to facilitate the slicing operation. The cured cake is preferably heated using infrared heat lamps during the slicing operation in which the cured cake is sliced into several polishing layers.
    Another method of manufacturing a chemical mechanical polishing felt of the present invention may include a drawing technique mixing the hardener in a fluid form, preferably as a melt, and the polyisocyanate prepolymer with any microelements in a vortex mixer to form the thermosetting reaction mixture, followed by pouring the mixture into a sheet using a draw bar or scraper, for example 60 to 60 cm (24 by 24 inches) with a given thickness , for example, 2 mm (80 mils) and hardening. The microelements are mixed in the polyisocyamate prepolymer before the addition of the hardener into the thermosetting reaction mixture. Curing may include heating an oven from room temperature to a set point temperature of 80 to 120 ° C, e.g. 104 ° C, holding for, for example, 4 to 24 hours at the set point temperature, and then creating a ramp of the oven set point temperature down to room temperature (21 ° C) over a period, for example, of a ramp 2 hours. The hardened sheet can be surfaced as with a lathe.
    According to the methods of manufacturing polishing felts according to the present invention, the chemical mechanical polishing felts can be provided with a pattern of grooves cut in their polishing surface to promote the flow of suspension and to remove polishing debris. of the felt-wafer interface. Such grooves can be cut from the polishing surface of the polishing felt using either a lathe or a CNC grinding machine.
    According to the methods of using the polishing felts of the present invention, the polishing surface of the CMP polishing felts can be conditioned. Conditioning or preparing the felt surface is critical to maintaining a consistent polishing surface for stable polishing performance. The polishing surface of the polishing felt wears out over time, smoothing the microstructure of the polishing surface - a phenomenon called glazing. The conditioning of the polishing felt is typically carried out by abrasion of the polishing surface mechanically with a conditioning disc. The conditioning disc has a rough conditioning surface typically consisting of incorporated diamond points. The packaging process cuts microscopic grooves in the felt surface, both abrading and plowing the felt material and renewing the polishing texture.
    The conditioning of the polishing felt comprises bringing a conditioning disc into contact with the polishing surface either during intermittent interruptions in the CMP process when the polishing is at rest (ex situ), or while the CMP process is in progress. course (in situ). The conditioning disc is typically rotated in a position which is fixed relative to the axis of rotation of the polishing felt, and scans an annular conditioning region when the polishing felt is rotated.
    The chemical mechanical polishing felt of the present invention can be used to polish a substrate chosen from at least one of a memory substrate and a semiconductor substrate.
    Semiconductor or three-dimensional memory substrates can have an element scale or a mold scale of 1-50 mm, preferably 1 to 20 mm between elements needing to be planarized.
    The method of polishing a substrate of the present invention preferably comprises: providing a substrate chosen from at least one of semiconductor substrates or three-dimensional memories, such as non-volatile flash memory substrates (3D NAND) ; the supply of a chemical mechanical polishing felt according to the present invention; creating dynamic contact between a polishing surface of the polishing layer and the substrate to polish a surface of the substrate; and, conditioning the polishing surface with an abrasive conditioner. In the methods of the present invention, creating dynamic contact includes polishing with a down force (DF) of 103 to 550 hPa (1.5 to 8 psi), or preferably
    206 to 483 hPa (3 to 7 psi). The DF can be more than 200 hPa to 550 hPa, preferably from 275 hPa to 475 hPa for use with suspensions with a lower abrasive content in the range of 0.5 to 2% by mass of abrasives , for example silica in solid state. The DF may also be lower, such as 103 to 344 hPa (1.5 to 5 psi) or, preferably, 137 to 344 hPa (2 to 5 psi), for use with suspensions with a higher content in abrasive from 2 to 6% by mass or, preferably, from 2.5 to 5.5% by mass.
    EXAMPLES: The present invention will now be described in detail in the following nonlimiting examples.
    Unless otherwise mentioned, all temperatures are room temperature (21-23 ° C) and all pressures are atmospheric pressure (~ 760 mm Hg or 101 kPa).
    Apart from other raw materials described below, the following raw materials were used in the examples:
    MONDUR ™ Quality II TDI: toluene diisocyanate (Covestro Pittsburgh, PA);
    TERATHANE ™ 1000: polytetra methylated ether glycol at Mw of 1000 (Invista, Wichita, KS);
    Adiprene ™ LF 750D: TDI prepolymer of low free form content (<0.5% max) of PTMEG (8.75 to 9.05% by mass of NCO, Mn = 760 Da; Mw = 870 Da, Chemtura, Philadelphia, PA);
    Adiprene ™ L 325: TDI-terminated liquid urethane prepolymer from PTMEG (8.95-9.25% by mass of NCO, Mn = 990 Da; Mw = 1250 Da, Chemtura);
    Prepolymer A: H12MDI-terminated liquid urethane quasi-prepolymer of PTMEG and TDI (~ 10.5% by mass of NCO) having - 64% by mass of H12MDI, based on the total mass of expiring aromatic and alicyclic diisocyanates; Mn ~ 760 Da; Mw ~ 870 Da;
    Adiprene ™ LFG 740D: TDI-terminated liquid urethane prepolymer with low free TDI content (<0.5% max) of polyol including PPG; (8.65-9.05% by mass of NCO, Chemtura);
    MDI prepolymer: linear isocyanate terminated urethane prepolymer of diphenylmethylene diisocyanate (MDI) and small molecule dipropylene glycol (DPG) and tripropylene glycol (TPG) with an NCO content of ~ 23% and an equivalent mass of 182. 100% by mass of this MDI prepolymer is treated as a hard segment;
    Lonzacure ™ MCDEA: 4,4'-methylene-bis (3-chloro-2,6-diethylaniline), (Lonza Ltd., Switzerland);
    Expancel ™ 551 beads DE 40 d42: polymer microspheres filled with fluid with a nominal diameter of 40 pm and an actual density of 42 g / l (Akzo Nobel, Arnhem, Netherlands);
    Expancel ™ 461 DE 20 d70 beads: polymer microspheres filled with fluid with a nominal diameter of 20 pm and an actual density of 70 g / l (Akzo Nobel); and
    Expancel ™ 031 DU 40 beads: dry, unexpanded polymeric microspheres with nominal diameter of 13 µm and an actual density of approximately 1,000 g / l (Akzo Nobel).
    The following other abbreviations appear in the examples below:
    TDI: toluene diisocyanate (~ 80% 2.4 isomer, ~ 20% 2.6 isomer); MbOCA: 4,4'-methylenebis (2-chloroaniline).
    Example 1: Synthesis of CMP polishing layers and felts: polishing layers were formed comprising the reaction product of the reaction mixture formulations as given in Table 1, below, by pouring the formulations into circular polytetrafluoroethylene molds (PTFE coated) diameter 86.36 cm (34) having a flat bottom for making moldings for use in the manufacture of polishing felts or polishing layers. To formulate the formulations, the indicated polyisocyanate prepolymer was heated to 52 ° C to ensure proper flow and combined with the indicated Expancel ™ microelement (s) to form a premixed component. which was then mixed with the hardener, as another component, using a high shear mixing head. After removing from the mixing head, the formulation was dispensed over a period of 2 to 5 minutes in the mold to provide a total pouring thickness of 4 to 10 cm and allowed to gel for 15 minutes before placing the mold in a hardening oven. The mold was then cured in the curing oven using the following cycle: a 30 minute ramp from room temperature to a setting point of 104 ° C, then held for 15.5 hours at 104 ° C, and then a 2 hour ramp from 104 ° C to 21 ° C. To cast the reaction mixture formulations as cakes, the felts were cast using an in-line prepolymer heat exchanger to reduce the prepolymer casting temperature to the indicated temperature from 52 ° C to 27 ° C (80 ° F ), and the molds were preheated to 93 ° C;
    this allows the control of the important exothermic reaction to mitigate the variation inside the mold.
    The porosity is proportional to the load of microspheres and inversely proportional to SG.
    Table 1: reaction mixtures
    Polishing layer prepolymer Hardener 1 Curing2 Hardener 1Hardener 2 Stoich. total (%) Porosity (% vol) Expancel ™ AT' L325 MbOCA - - 87 35% 551 DE 40 d42 B ' L325 MbOCA - - 105 37% 461 DE 20 d70 VS* LF 750 D and prepolymerMDI MbOCA - - 105 19% 461 DE 20 d70 D LF 750 D - MCDEA - 105 17% 461 DE 20 d70 E * LF 750D MbOCA - - 105 19% 461 DE 20 d70
    F * LFG 740D and LF 750D (4: 1) MbOCA - - 105 16% 461 DE 20 d70 G LF 750D MbOCA MCDEA 1: 1 105 18% 461 DE 20 d70 H L325 - MCDEA - 105 17% 461 OF 20d70 I L325 and prepolymerA (1: 1) - MCDEA - 105 20% 461 DE 20 d70
    461 OF 20 J L325 MbOCA MCDEA 1: 1 87 47% d70 andÏ ------------ -----031 FROM 40
    - Indicates Comparative Example.
    The cured polyurethane cakes were then removed from the mold and sliced (cut using a stationary blade) at a temperature of 70 to 90 ° C into approximately thirty separate sheets of 2.0 mm (80 mil) thickness . Slicing was started from the top of each cake. We threw away all the incomplete sheets.
    The non-grooved polishing layer materials were analyzed for each example to determine their physical properties. Note that the data on felt densities cited were determined according to ASTM D1622-08 (2008); the cited Shore D hardness data were determined according to ASTM D2240-15 (2015); and, the cited modulus and elongation at break data were determined according to ASTM D412-6a (2006). The test results are shown in Tables 2, 3, 4, 5 and 6, below.
    Test Methods: Including the property tests indicated above, the following methods were used to test the polishing felts.
    Polishing: mechanochemical polishing felts were constructed using polishing layers. These machine polishing layers were then grooved to provide a pattern of grooves in the polishing surface comprising perforations or more concentric circular grooves having the following dimensions: in Examples 2 and 3 were used perforated felts which had a Suba ™ 400 calibrated urethane polyester mat felt (Nitta Haas, JP); in Example 4, 1,010 grooves 0.76 mm (30 mil) deep, 0.51 mm (20 mil) wide, and not 3.05 mm (120 mil).
    The polishing layers were then laminated to a layer of foam underlay (SUBA IV available from Rohm and Haas Electronic Materials CMP Inc.). The resulting felts were attached to the polishing disc of the indicated polishing device using a film of double-sided pressure-sensitive adhesive.
    A CMP polishing platform, shown below, was used to polish the indicated substrates with the markers indicated. The polishing medium indicated in the polishing experiments was used (for example a cerium oxide suspension CES333F, Asahi Glass Company, JP). Unless otherwise noted (such as disc rpm (PS) / support rpm (CS)), the polishing conditions used in all polishing experiments included a disc speed of 93 rpm; a support speed of 87 rpm; with a polishing medium flow of 200 ml / min and with the indicated down force (DF). An AM02BSL8031C1PM (AK45) diamond conditioning disc (Saesol Diamond Ind. Co., Ltd.) was used to condition the chemical mechanical polishing felts. The chemical mechanical polishing felts were each run in with the conditioner using a down force of 3.2 kg (7 pounds) for 40 minutes. The polishing felts were further conditioned in situ using a downward force of 3.2 kg (7 pounds). The withdrawal rates (RR) were determined by measuring the film thickness before and after polishing using an FX200 metrology tool (KLA-Tencor, Milpitas, CA) using a 49-point helical scan with edge exclusion 3 mm.
    Tread height: the difference measured between the low surface level and the element level, as determined by optical interference using a RE-3200 ellipsometric film thickness measurement system (Screen Holdings Co. Ltd., JP). The remaining step height is advantageously as low as possible.
    Example 2: Cerium oxide suspension polishing on a wafer substrate: in Table 2, below, the CMP polishing felts indicated in a polishing, as defined above, were tested with a polishing platform FREX ™ 300 (Ebara, Tokyo, JP) at a falling force of 410 hPa (6 psi) using a suspension of cerium oxide Hitachi HS8005 (Hitachi, Corp., JP) with a final solid content of 0.5 % by mass (1: 9 dilution), 240 nm (d50) and pH ~ 8.4, and the substrate was a film of tetraethoxyorthosilicate oxide (TEOS) on a patterned polysilicon wafer. The indicated CMP polishing felts were subjected, before polishing, to ex-situ conditioning for 30 s at a DF of 100N using a Kinik EP1AG150730-NC ™ conditioning disc (Kinik, Tapei, TW).
    Table 2: Withdrawal rates with a suspension of cerium oxide
    Polishing layer felt Withdrawal speed (Â / min) Step height at250 pm Step height at 4 mm Temp. polishing (C °) G 'at 50 ° C (MPa) G ’at 65 ° C (MPa) G 'at 90 ° C (MPa) A '' 1 5,174 1,300 3,900 61 184 131 79 B * 5,891 1,100 3,400 64 208 142 80 H 6,503 1,500 3,100 65 264 203 138 F * 4,109 800 2,900 53 146 108 73 I 6,975 1,500 3,900 73 296 240 183
    * - indicates Comparative Example; 1. IC1000 felt (Dow) made using the prepolymer ADIPRENE ™ L325 (Chemtura)
    As shown in Table 2, above, the CMP H and I polishing felts of the present invention provided a much higher removal speed than that of the art closest to the CMP A and B polishing felts.
    Example 3: suspension polishing of cerium oxide on an element substrate: in Table 3, below, the CMP polishing felts indicated in the polishing were tested as defined in Example 2, above , at a DF of 500 hPa (7.25 psi) with a suspension of cerium oxide Hitachi HS8005 ™ at a final solid content of 0.5% by mass (dilution 1: 9), 240 nm (d50) and pH ~ 8.4, except for a disc / support speed (100/107 rpm) and the substrate was a film of tetraethoxyorthosilicate oxide (TEOS) on a patterned polysilicon wafer.
    Table 3: Withdrawal speeds and planarization on the length scale with a suspension of cerium oxide
    Polishing layer felt Withdrawal speed (Â / min) Step height at 250 pm Step height at 4 mm Temp. polishing (° C) G ’at 50 ° C (MPa) G 'at 65 ° C (MPa) G 'at 90 ° C (MPa) A * - 1 5,380 1,300 4,400 74 184 131 79 B * 7,640 1,200 4,250 84 208 142 80 VS* 8,250 900 3,800 83 349 224 68 D 10,560 1,700 3,900 88 255 220 184 E ' 5,990 800 3,650 76 123 83 55 F ' 4,930 800 3,400 70 146 108 73
    * - Indicates Comparative Example; 1. IClOOO felt (Dow).
    As shown in Table 3, above, the preferred CMP D polishing felt of the present invention has a much higher shrinkage rate than that of the technique closest to the CMP E polishing felt, which is made from of the same polyisocyanate prepolymer at the same stoichiometry, however, without the hardener of the present invention.
    Example 4: Polishing at different withdrawal speeds: in Table 4, below, the CMP polishing felts indicated in the polishing were tested as defined above with an Ebara Reflexion polishing device (300 mm, Ebara) and using a cerium oxide suspension (pH 3.5 and average particle size of 150 nm) at a solids content of 6% by mass, at the indicated support / disc speed and at the downward force (DF) indicated. The substrate was a tetraethoxyorthosilicate (TEOS) film on a patterned polysilicon wafer.
    Table 4: Withdrawal speeds and planarization on the long-scale with a suspension of cerium oxide at different downward forces
    Polishing layer felt Polishing down force (psi) PS / CS (rpm) Withdrawal speed (Â / min) Step height at 50% PD 2 Temp. polishing (° C) A * ' 1 2.0 110/103 8,90054 D 2.0 110/103 9,00053 G 2.0 110/103 9,10053 A * ' 1 2.5 110/103 10,600 820 60 D 2.5 110/103 11,000 370 59 G 2.5 110/103 11,000 0 58 A * ' 1 3.0 110/103 12,00066 D 3.0 110/103 12,90065 G 3.0 110/103 12,90065 A '' 1 2.3 123/117 10,60053 G 2.3 123/117 11,10053 A '' 1 3.0 123/117 12,60062 G 3.0 123/117 13,90063 A '· 1 3.5 123/117 13,80067 G 3.5 123/117 15,20068 A * ' 1 4.0 123/117 14,40072 G 4.0 123/117 16,80073
    * - indicates Comparative Example; 1. IC1000 felt (Dow); 2. Pattern density.
    As shown in Table 4, above, the CMP D and G polishing felts of the present invention provide a higher removal speed than that of the technique in CMP A polishing felt 10, which is not manufactured with the hardener of the present invention or with the stoichiometry of the present invention. G felt made from a mixture of MCDEA hardeners, MbOCA, provided the best results. The step height data taken at 172 hPa (2.5 psi DF) indicates that the felt of the present invention improves planarity on the long length scale. The RR data shows that there is a greater improvement for the felts of the invention compared to the comparative polishing felt at a higher DF and at higher disc / support speeds.
    Example 5: Polishing of copper metal and tungsten: polishing layers J1-J3 were constructed according to the reaction mixture formulation as given in Table 1 for the polishing layer J, using a combination of 2.91% by mass of Expancel ™ 461 DE 20 d70 and 1.7% by mass of Expancel ™ 031 DU 40, and their properties are presented, below, in Table 5. The inclusion of Expancel ™ 031 DU 40 helps further increase the porosity of the felt and reduce the SG of the felt to approximately 0.63. Polishing layer A was similarly prepared for comparative purposes according to Table 1 but modified to include a combination of 2.91% by mass of Expancel ™ 461 DE 20 d70 and 1.7% by mass of Expancel ™ 031 DU
    40.
    Table 5: Properties of polishing layer J
    Polishing layer Density g / cm 3 Shore D G 'at 50 ° C (MPa) G 'at 65 ° C (MPa) G 'at 90 ° C (MPa) Tan-delta at 50 ° C J1 0.63 53 104 80 45 0,102 J2 0.64 54 120 86 47 0,075 J3 0.63 55 109 not 42 0.074
    Mechanical chemical polishing felts, felt J and comparative felt A, were constructed using the corresponding polishing layers described above and tested for polishing copper or tungsten film on a substrate. wafer.
    The polishing layers were machine grooved to provide a pattern of grooves in the polishing surface comprising several concentric circular grooves having the following dimensions: K7 grooves 0.76 mm (30 mils) deep, 0.51 mm wide ( 20 mils), not 1.78 mm (70 mils), with 32 additional counts of radial grooves 0.76 mm (30 mils) deep and 0.76 mm (30 mils) wide.
    The polishing layers were then laminated onto a layer of foam underlay (SUBA IV available from Rohm and Haas Electronic Materials CMP Inc.). The resulting felts were fixed to the polishing disc using a film of double-sided pressure-sensitive adhesive. The final felt has a diameter of 775 mm (30.5).
    A CMP polishing platform, Reflexion ™ LK from Applied Materials (Santa Clara, CA) was used to polish 300 mm wafers. Polishing conditions included a disc speed of 93 rpm; a support speed of 87 rpm; with a polishing medium flow of 300 mL / min.
    We evaluated the multiple CMP polishing suspensions including a bulk copper suspension CSL9044 comprising 1.5% by mass of colloidal silica abrasive and 1% by mass of H 2 O 2 , with a pH around 7 during the use (Fujifilm Planar Solutions, Japan) and a suspension of bulk tungsten W2000 ™ comprising 2% by mass of fumed silica abrasive and 2% by mass of H 2 O 2 , with a pH of 2 to 2.5 during use (Cabot Microelectronics, Aurora, IL). Each suspension was used to polish the following substrates:
    • CSL90144C (copper polishing): Cu wafers at 3 psi (20.7 kPa);
    • W2000 (polishing of tungsten): wafers of sheets of W, TEOS, and SiN at 2 psi (13.8 kPa) and 4 psi (27.6 kPa)
    Before the polishing, an AM02BSL8031C1-PM conditioning disc (AK-45 ™ disc, Saesol Diamond Ind. Co., Ltd., Gyeonggi-do, Korea) was used for lapping and conditioning of CMP polishing felts. Each new felt was lapped for 30 minutes at a downward force of 7 pounds (31 N) with an additional lapping of 5 minutes before a suspension modification. During polishing, 100% in-situ conditioning at 5 pounds (22 N) was used for copper polishing, and ex-situ conditioning from 30 s to 7 pounds (31 N) for polishing tungsten. 10 dummy wafers were polished and then three wafers for which the polishing shrinkage rates and other polishing indices were determined.
    The removal rates were determined by measuring the film thickness before and after polishing using an FX200 metrology tool (KLA-Tencor, Milpitas, CA) using a 49-point helical scan with an edge exclusion of 3 mm .
    The polishing results for the removal speed (RR) are shown in Tables 6 and 7 below. The standardized results fix the comparative result at 100% or by unit, when this is applicable.
    The% of non-uniformity (% NU):% NU was determined by calculating the interval of final film thickness after polishing. The polishing results in% NU are shown in Tables 6 and 7, below.
    Table 6: Copper polishing withdrawal speeds with CSL9044C suspension
    Polishing layer felt Polishing down force Average RR (Â / min) % NU RR normalized Temp. polishing (° C) AT* 20.7 kPa(3 spinnaker) 8,926 5.9 100% 62.9 J 20.7 kPa(3 spinnaker) 11,097 5.5 124% 62.1
    * - Indicates Comparative Example.
    Table 7: Tungsten polishing withdrawal speeds with W2000 suspension
    Polishing layer felt Polishing down force Average RR (Â / min) % NU RR normalized Temp. polishing (° C) AT* 13.8 kPa (2 psi) 1,868 6.8 100% 49.9 J 13.8 kPa (2 psi) 2,109 6.8 113% 48.8 AT' 27.6 kPa (4 psi) 3,877 3.8 100% 66.6
    J 27.6 kPa (4 psi) 5,547 4.0 143% 68.2
    * - Indicates Comparative Example.
    As shown in Tables 6 and 7 above, the felt J demonstrated a significant improvement over the felt of Comparative Example A, particularly at a high polishing temperature.
    权利要求:
    Claims (10)
    [1" id="c-fr-0001]
    1. Mechanical chemical polishing felt (CMP) having a low damping constituent for polishing a substrate chosen from at least one of a memory and a semiconductor substrate comprising: a polishing layer suitable for polishing the substrate which is a polyurethane reaction product of a thermosetting reaction mixture comprising a hardener of 4,4'-methylenebis (3-chloro-2,6-diethyaniline) (MCDEA) or mixtures of MCDEA and 4,4'-methylene- bis-o- (2chloroaniline) (MbOCA) in a mass ratio of MCDEA to MbOCA of 3: 7 to 1: 0, and of a polyisocyanate prepolymer having an unreacted isocyanate (NCO) concentration of 8, 6 to 11% by mass and formed from one or two aromatic diisocyanates or from a mixture of an aromatic diisocyanate and up to 67% by mass of an alicyclic diisocyanate, based on the total mass of the aromatic diisocyanates and alicyclic, and a polytetramethylene ether glycol polyol (PTMEG) , polypropylene glycol (PPG), or a combination of PTMEG and PPG polyols as reactants, characterized in that the polyurethane reaction product in the polishing layer has a Shore D hardness according to ASTM D2240-15 (2015) from 50 to 90, the polyurethane reaction product in the polishing layer has a shear modulus during storage (G 1 ) at 65 ° C. from 70 to 500 MPa, and, the polishing layer has a damping component ( G / G 'measured by dynamic mechanical shear analysis (DMA), ASTM D5279-08 (2008)) at 50 ° C from 0.06 to 0.13.
    [2" id="c-fr-0002]
    2. CMP polishing felt according to claim 1, characterized in that the hardener comprises a mixture of MCDEA and 4,4'methylene-bis-o- (2-chloroaniline) (MbOCA) in a mass ratio of MCDEA to MbOCA from 4: 6 to 1: 0.
    [3" id="c-fr-0003]
    3. CMP polishing felt according to claim 1 or 2, characterized in that the aromatic diisocyanate or mixture thereof with an alicyclic diisocyanate is chosen from toluene diisocyanate (TDI), TDI mixed with up to 20% by mass, based on the total mass of the aromatic diisocyanate, of diphenylmethylene diisocyanate (MDI), or a mixture of TDI and up to 67% by mass of H12MDI,
    reported to the total mass of diisocyanate aromatic and alicyclic. 4. Felt of CMP polishing according to one any of the claims 1 at 3, characterized by that the prepolymer of
    polyisocyanate has a concentration of unreacted isocyanate (NCO) of 8.6 to 10.3% by mass of the polyisocyanate prepolymer, and the polyol used to form the polyisocyanate prepolymer is chosen from (i) PTMEG, (ii ) PPG or (iii) a combination of PTMEG and PPG polyols in a PTMEG to PPG ratio of 1: 0 to 1:
    [4" id="c-fr-0004]
    4 or 12: 1 to 1: 1.
    [5" id="c-fr-0005]
    5. CMP polishing felt according to any one of claims 1 to 4, characterized in that the stoichiometric ratio of the sum of all of the moles of amine groups (NH 2 ) and of all of the moles of hydroxyl groups (OH ) in the reaction mixture to all of the unreacted isocyanate (NCO) moles in the reaction mixture is from 0.90: 1 to 1.20: 1.
    [6" id="c-fr-0006]
    6. CMP polishing felt according to any one of claims 1 to 5, characterized in that the polishing layer of the CMP polishing felt further comprises microelements chosen from trapped gas bubbles, polymeric materials with hollow cores, polymeric materials with hollow cores charged with liquid, and fillers.
    [7" id="c-fr-0007]
    7. CMP polishing felt according to any one of claims 1 to 6, characterized in that the polyurethane reaction product in the polishing layer has a Shore D hardness according to ASTM D2240-15 (2015) from 60 to 90 and a storage shear modulus (G 1 ) at 65 ° C from 125 to 500 MPa.
    [8" id="c-fr-0008]
    8. CMP polishing felt according to any one of claims 1 to 7, characterized in that the polishing felt or the polishing layer has a density of 0.55 to 1.17 g / cm 3 .
    [9" id="c-fr-0009]
    9. CMP polishing felt according to any one of claims 1 to 8, characterized in that the polishing layer comprises a polyurethane reaction product having a hard segment of 45 to 70%, based on the total mass of the reaction mixture thermosetting.
    [10" id="c-fr-0010]
    10. A chemical mechanical polishing (CMP) method of a substrate, comprising: providing a substrate chosen from at least one of a semiconductor or three-dimensional memory substrate; providing a chemical mechanical polishing felt (CMP) according to any one of claims 1 to 9; providing an abrasive polishing medium; and creating dynamic contact between a polishing surface of the polishing layer of the CMP polishing felt, the abrasive polishing medium and the substrate to polish a surface of the substrate at a falling force (DF) from 103 to 550 hPa ( 1.5 to 8 psi); and conditioning the polishing surface of the polishing felt with an abrasive conditioner.
    类似技术:
    公开号 | 公开日 | 专利标题
    US10086494B2|2018-10-02|High planarization efficiency chemical mechanical polishing pads and methods of making
    FR3066940A1|2018-12-07|MECHANICAL CHEMICAL POLISHING FELTS FOR IMPROVED RECOVERY AND PLANARIZATION SPEED
    TWI480123B|2015-04-11|Multi-functional polishing pad
    US20100035529A1|2010-02-11|Chemical mechanical polishing pad
    FR2901498A1|2007-11-30|MECHANICAL-CHEMICAL POLISHING FELT
    US10722999B2|2020-07-28|High removal rate chemical mechanical polishing pads and methods of making
    FR2901499A1|2007-11-30|MECANO-CHEMICAL POLISHING FELT
    CN108115554B|2020-11-17|Improved composition for chemical mechanical polishing pad and CMP pad prepared therefrom
    TWI728246B|2021-05-21|Porous polyurethane polishing pad and process for preparing a semiconductor device by using the same
    TW201700521A|2017-01-01|Chemical mechanical polishing pad composite polishing layer formulation
    TW201900336A|2019-01-01|Porous polyurethane polishing pad and method for preparing the same using the same
    FR3030552A1|2016-06-24|METHOD FOR MANUFACTURING CONTROLLED VISCOSITY CMP POLISHING PAD
    FR3030551A1|2016-06-24|METHOD FOR MANUFACTURING CONTROLLED EXPANSION CMP POLISHING PAD
    FR3030335A1|2016-06-24|POLYURETHANE POLISHING PAD WITH HIGH STABILITY
    TW202116845A|2021-05-01|Polishing pad, process for preparing the same, and process for preparing a semiconductor device using the same
    US10391606B2|2019-08-27|Chemical mechanical polishing pads for improved removal rate and planarization
    TWI735101B|2021-08-01|Composition for a polishing pad, polishing pad, and process for preparing the same
    TWI753007B|2022-01-21|High planarization efficiency chemical mechanical polishing pads and methods of making
    US10464187B2|2019-11-05|High removal rate chemical mechanical polishing pads from amine initiated polyol containing curatives
    TW202122475A|2021-06-16|Polishing pad, preparation method thereof, and preparation method of semiconductor device using same
    CN1504295A|2004-06-16|Method for producing integrated PU grinding pad
    同族专利:
    公开号 | 公开日
    DE102018004452A1|2018-12-06|
    CN108994722B|2021-08-17|
    US20180345449A1|2018-12-06|
    FR3066940B1|2022-02-04|
    CN108994722A|2018-12-14|
    TW201903047A|2019-01-16|
    JP2019012817A|2019-01-24|
    KR20180133315A|2018-12-14|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20010050268A1|2000-05-23|2001-12-13|Reinhardt Heinz F.|Polishing pad of a polyurethane of propane diol|
    SG111222A1|2003-10-09|2005-05-30|Rohm & Haas Elect Mat|Polishing pad|
    CN101489721B|2006-08-28|2014-06-18|东洋橡胶工业株式会社|Polishing pad|
    US20090062414A1|2007-08-28|2009-03-05|David Picheng Huang|System and method for producing damping polyurethane CMP pads|
    CN102310366B|2010-07-08|2014-03-05|罗门哈斯电子材料Cmp控股股份有限公司|Chemical mechanical polishing pad with low-defect overall window|
    US20150059254A1|2013-09-04|2015-03-05|Dow Global Technologies Llc|Polyurethane polishing pad|
    US20150306731A1|2014-04-25|2015-10-29|Rohm And Haas Electronic Materials Cmp Holdings, Inc.|Chemical mechanical polishing pad|CN111318957A|2018-12-14|2020-06-23|夏泰鑫半导体有限公司|Polyurethane polishing pad, method for producing same, and chemical mechanical polishing apparatus|
    KR102237351B1|2019-06-17|2021-04-07|에스케이씨솔믹스 주식회사|Composition for polishing pad, polishing pad and preparation method of semiconductor device|
    KR102237362B1|2019-06-17|2021-04-07|에스케이씨솔믹스 주식회사|Composition for polishing pad, polishing pad and preparation method of semiconductor device|
    CN110528287B|2019-08-08|2022-03-08|安徽安利材料科技股份有限公司|Brush type high-durability chemical mechanical polishing polyurethane material and preparation method thereof|
    法律状态:
    2020-05-12| PLFP| Fee payment|Year of fee payment: 3 |
    2021-05-07| PLSC| Publication of the preliminary search report|Effective date: 20210507 |
    2021-05-13| PLFP| Fee payment|Year of fee payment: 4 |
    优先权:
    申请号 | 申请日 | 专利标题
    US15615254|2017-06-06|
    US15/615,254|US10391606B2|2017-06-06|2017-06-06|Chemical mechanical polishing pads for improved removal rate and planarization|
    US15/924,606|US20180345449A1|2017-06-06|2018-03-19|Chemical mechanical polishing pads for improved removal rate and planarization|
    US15924606|2018-03-19|
    [返回顶部]