Polishing pad with filled non-porous subpad

Abstract

To provide a polishing pad having a filled nonporous subpad.SOLUTION: A polishing pad for chemical mechanical polishing includes a polishing layer and a subpad. The polishing layer has a polishing surface and a polishing layer interface opposite the polishing surface and comprises a polishing material. The subpad layer has a subpad interface adjacent the polishing layer interface and a bottom surface opposite the subpad interface, and comprises a subpad material. The subpad layer has an average modulus of elasticity of 1 to 48kPa under compression at pressures from 24 to less than 5MPa and an average modulus of elasticity of 5 to 76kPa under compression at pressures from 48 to 20MPa and a true strain of 10% or less for compressive pressures up to 1. 2MPa.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The field of the invention is polishing pads used in chemical mechanical polishing. [Background technology]

[0002] Chemical mechanical planarization (CMP) is a type of polishing process widely used to flatten or planarize the building layers of integrated circuits or similar structures. Specifically, CMP is frequently used to produce flat, uniform layers of a specified thickness in the fabrication of three-dimensional circuit structures through additive deposition and planarization. CMP can remove excess material deposited on the substrate (e.g., wafer) surface to produce an extremely flat layer of uniform thickness, with the uniformity prevailing across the entire substrate (e.g., wafer) area. When the uniform thickness prevails across the entire wafer, this is known as global uniformity.

[0003] CMP uses a liquid, often called a slurry, which may contain nano-sized particles. The slurry is dispensed onto the surface of a rotating multilayer polymer pad (sometimes called a polishing sheet), which is mounted on a rotating platen. The polishing pad includes a polishing layer and may include a subpad. A substrate (e.g., a wafer) is mounted on a separate fixture or carrier with a separate rotation mechanism and pressed against the pad surface under a controlled load. This can result in high-speed relative motion between the substrate (e.g., wafer) and the polishing pad, and high shear or wear rates on both the substrate and the pad surface. Slurry particles trapped at the shear and pad / substrate interface abrade the substrate (e.g., wafer) surface, removing material from the substrate surface. Control of the removal rate and uniformity of removal are important. Summary of the Invention [Problem to be solved by the invention]

[0004] Polishing pads include polymeric materials that may be porous. Therefore, polishing pads are generally thermally insulating. In addition, the compressibility of polishing pads can result in variations in polishing performance across the diameter of the pad. [Means for solving the problem]

[0005] Disclosed herein is a polishing pad for chemical mechanical polishing, comprising a polishing layer and a subpad. The polishing layer has a polishing surface and a polishing-layer interface facing the polishing surface, and comprises a polishing material. The subpad layer has a subpad interface adjacent to the polishing-layer interface and a bottom surface facing the subpad interface, and comprises a subpad material. The subpad layer has an average modulus of elasticity of 1 to 5 MPa under compression at a pressure of 24 to less than 48 kPa, an average modulus of elasticity of 5 to 20 MPa under compression at a pressure of 48 to 76 kPa, and a true strain of 10% or less at a maximum compression pressure of 1.2 MPa.

[0006] Reference will now be made to the drawings of exemplary embodiments, wherein like elements are numbered alike. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a top view of an example of a polishing pad as disclosed herein. [Figure 2] 2 is a cross-sectional view through the thickness of a polishing pad as in FIG. 1 a-a' showing one embodiment of a polishing pad as disclosed herein. [Figure 3] 2 is a cross-sectional view through the thickness of a polishing pad as in FIG. 1 a-a' showing a second embodiment of a polishing pad as disclosed herein. [Figure 4] 1 is a graph of true stress versus true strain for a sample pad as shown in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0008] As shown in Figures 1-3, pad 1 has polishing layer 10 and subpad 20. The polishing layer has an upper polishing surface 12, a polishing-layer interface 16, and a thickness t. Optional recesses 14, shown in Figure 1 as concentric grooves, may be found in polishing layer 10. While recesses 14 are shown as concentric grooves, other recess shapes, such as radial grooves extending from the center of the pad, cross-hatch grooves, or combinations thereof, may also be used. The presence of recesses is preferred. Recesses 14 have a depth d. For a new pad, depth d may be at least 80, at least 90, at least 95, or at least 98% of thickness t, as shown in Figure 2. As polishing layer 10 in Figure 2 wears from top to bottom during polishing and diamond conditioning, this percentage decreases. Optionally, for higher heat flow rates, thickness t may be 100% of thickness t, as shown in Figure 3. As the abrasive layer 10 of FIG. 3 wears from top to bottom, this percentage remains constant at 100% of the thickness.

[0009] The subpad 20 has a subpad interface 26 and a subpad bottom surface 22. A pressure-sensitive or hot-melt adhesive (not shown) can bond the subpad to the polishing layer. The polishing pad 1 can include an optional endpoint detection window 100.

[0010] The thickness t of the polishing layer can be, for example, from 0.5 or 1 mm up to 4, up to 3, or up to 2 mm. The thickness of the subpad layer can be, for example, from 0.5 or 1 mm up to 4, up to 3, up to 2, or up to 1.5 mm.

[0011] The amount of top pad material at the bottom of the recess may be less than 0.5 mm, less than 0.4 mm, less than 0.3 mm, less than 0.2 mm, or less than 0.1 mm, or all of the top pad material may be removed in the recess to expose the underlying layer, e.g., the subpad.

[0012] The polishing layer 10 may comprise a polymer. The polishing layer 10 may be porous. Pores can be provided, for example, by the addition of hollow flexible polymer elements (e.g., hollow microspheres), blowing agents, foaming, or supercritical carbon dioxide. Examples of polymeric materials for the polishing layer include polyurethane, polycarbonate, polysulfone, nylon, polyether, polyester, polystyrene, acrylic polymers, polymethyl methacrylate, polyvinyl chloride, polyvinyl fluoride, polyethylene, polypropylene, polybutadiene, polyethyleneimine, polyethersulfone, polyamide, polyetherimide, polyketone, epoxy resin, silicone, copolymers thereof (e.g., polyether-polyester copolymers), and combinations or blends thereof. The polishing layer may comprise a polymer that is a polyurethane formed by the reaction of one or more polyfunctional isocyanates and one or more polyols. For example, a polyisocyanate-terminated urethane prepolymer can be used. The polyfunctional isocyanate used in forming the polishing layer of the chemical mechanical polishing pad of the present invention can be selected from the group consisting of aliphatic polyfunctional isocyanates, aromatic polyfunctional isocyanates, and mixtures thereof. For example, the polyfunctional isocyanate used in forming the polishing layer of the chemical mechanical polishing pad of the present invention can be a diisocyanate selected from the group consisting of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, tolidine diisocyanate, para-phenylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, and mixtures thereof. The polyfunctional isocyanate can be an isocyanate-terminated urethane prepolymer formed by reacting a diisocyanate with a prepolymer polyol. The isocyanate-terminated urethane prepolymer may have 2 to 12 weight percent, 2 to 10 weight percent, 4 to 8 weight percent, or 5 to 7 weight percent unreacted isocyanate (NCO) groups.The prepolymer polyol used to form the polyfunctional isocyanate-terminated urethane prepolymer can be selected from the group consisting of diols, polyols, polyol diols, copolymers thereof, and mixtures thereof. For example, the prepolymer polyol can be selected from the group consisting of polyether polyols (e.g., poly(oxytetramethylene) glycol, poly(oxypropylene) glycol, and mixtures thereof), polycarbonate polyols, polyester polyols, polycaprolactone polyols, mixtures thereof, and mixtures thereof with one or more low molecular weight polyols selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, and tripropylene glycol. For example, the prepolymer polyol may be selected from the group consisting of polytetramethylene ether glycol (PTMEG), ester-based polyols (ethylene adipate, butylene adipate, etc.), polypropylene ether glycol (PPG), polycaprolactone polyols, copolymers thereof, and mixtures thereof. For example, the prepolymer polyol may be selected from the group consisting of PTMEG and PPG. When the prepolymer polyol is PTMEG, the isocyanate-terminated urethane prepolymer may have an unreacted isocyanate (NCO) concentration of 2 to 10 wt % (more preferably 4 to 8 wt %, most preferably 6 to 7 wt %).Examples of commercially available PTMEG-based isocyanate-terminated urethane prepolymers include Imuthane® prepolymers (available from COIM USA, Inc., e.g., PET-80A, PET-85A, PET-90A, PET-93A, PET-95A, PET-60D, PET-70D, and PET-75D); Adiprene® prepolymers (available from Chemtura, e.g., LF800A, LF900A, LF910A, LF930A, LF931A, LF939A, LF950A, LF952A, LF600D, LF601D, LF650D, LF667, LF700D, LF750D, LF751D, LF752D, LF753D, and L325); and Andur® prepolymers (available from Anderson Development Available from Polypropylene Company, for example, 70APLF, 80APLF, 85APLF, 90APLF, 95APLF, 60DPLF, 70APLF, and 75APLF. When the prepolymer polyol is PPG, the isocyanate-terminated urethane prepolymer may have an unreacted isocyanate (NCO) concentration of 3 to 9 wt % (more preferably 4 to 8 wt %, and most preferably 5 to 6 wt %). Examples of commercially available PPG-based isocyanate-terminated urethane prepolymers include Imuthane® prepolymers (PPT-80A, PPT-90A, PPT-95A, PPT-65D, PPT-75D, etc., available from COIM USA, Inc.); Adiprene® prepolymers (LFG963A, LFG964A, LFG740D, etc., available from Chemtura); and Andur® prepolymers (8000APLF, 9500APLF, 6500DPLF, 7501DPLF, etc., available from Anderson Development Company). The isocyanate-terminated urethane prepolymer may be a low-free isocyanate-terminated urethane prepolymer having a free toluene diisocyanate (TDI) monomer content of less than 0.1% by weight. Non-TDI-based isocyanate-terminated urethane prepolymers can also be used.For example, isocyanate-terminated urethane prepolymers such as those formed by reacting a polyol such as 4,4'-diphenylmethane diisocyanate (MDI) and polytetramethylene glycol (PTMEG) with an optional diol such as 1,4-butanediol (BDO) are acceptable. When such isocyanate-terminated urethane prepolymers are used, the unreacted isocyanate (NCO) concentration is preferably 4 to 10 wt% (more preferably 4 to 10 wt%, most preferably 5 to 10 wt%). Examples of commercially available isocyanate-terminated urethane prepolymers in this category include Imuthane® prepolymers (e.g., 27-85A, 27-90A, 27-95A, etc., available from COIM USA, Inc.); Andur® prepolymers (e.g., IE75AP, IE80AP, IE 85AP, IE90AP, IE95AP, IE98AP, etc., available from Anderson Development Company); and Vibrathane® prepolymers (e.g., B625, B635, B821, etc., available from Chemtura).

[0013] The subpad layer 20 is nonporous. The subpad layer 20 has an average modulus of elasticity of 1 to less than 5 megapascals (MPa) at a compression pressure of up to 48 kilopascals (kPa) (e.g., a pressure of 24 to 48 kPa) and an average modulus of elasticity of 5 to 20 MPa at a compression pressure of 48 to 76 kilopascals (kPa) under compression. For purposes of this specification, the average modulus of elasticity (or compressibility in the elastic region) represents the average value measured from the low to the high value of the compression pressure range. The subpad may have a true strain of 10% or less for a compression pressure of up to 1.2 MPa. This compressibility profile allows for profile tuning, such as edge effect tuning. Specifically, the subpad may have sufficient compressibility to increase overall polishing uniformity while simultaneously limiting excessive subpad deformation to promote a more uniform edge profile for increased semiconductor wafer yield. Another advantage of this subpad is that it can remain mechanically stable across multiple wafers, eliminating the problem of slurry wicking into the subpad. These modulus and strain values ​​were measured using the following procedure: Indentation tests can be performed on an MTS-Electromechanical Test Systems-Criterion 43 equipped with a 1 kilonewton (kN) load cell and compression platens. The upper platen can be modified to include a stainless steel indenter with a radius of approximately 10 mm at its center and a capacitance sensor around the indenter for measuring displacement between the platens. Samples can be die-cut to a 2-inch radius circle with the sample thickness. The indenter is moved downward at a fixed crosshead speed until the load reaches a specified force value, then moved back to its original position at the same speed. The resulting force vs. displacement curve is converted to a true stress vs. true strain curve, which is then used to calculate the secant modulus value using the load curve.

[0014] The subpad optionally includes a particulate filler in a polymer matrix material. The particulate filler can be thermally conductive such that the subpad has a subpad thermal conductivity of greater than 1, at least 2, or at least 3 Watts per meter per Kelvin (W / mK), and can be up to 20 or up to 10 W / mK. Advantageously, the thermal conductivity is between 1 and 35 W / mK. More advantageously, the thermal conductivity is between 2 and 20 W / mK. Most advantageously, the thermal conductivity is between 2 and 10 W / mK.

[0015] Thermal conductivity was measured using a device such as a thermal interface material tester or according to ASTM D5470 for measuring thermal resistance and conductivity on thin materials. For example, a thermal interface material tester from Analysis Tech can be used. For example, five samples of 1-inch (2.54 cm) diameter subpad material were stacked in series and placed between hot and cold surfaces under load, starting at room temperature, and allowed to equilibrate to determine heat flux. The samples were loaded sequentially on top of each other with silicone oil applied between them to limit interface effects. A plot of heat flux versus thickness can then be used to determine thermal conductivity from the slope of the plot.

[0016] The thermal conductivity of the subpad can be constant from end to end of the pad. The thermal conductivity of the subpad can be constant through the thickness of the pad or there can be variations in thermal conductivity through the thickness of the pad. The subpad layer is non-porous. The composition of the subpad can be constant throughout the subpad. For example, the subpad can have a monolithic structure.

[0017] The particles are preferably not electrically conductive. The particles may be inorganic. The particles may be layered (i.e., having a plate-like shape, multiple layers of inorganic material, or both). Examples of layered particles include boron nitride particles and graphite. Examples of particularly thermally conductive particles may be, for example, aluminum oxide, boron nitride, aluminum nitride, magnesium oxide, and zinc oxide. Boron nitride particles are preferred. The particles (e.g., boron nitride particles) may have a particle size of up to 30 microns, such as 1 to 20 microns or 1 to 15 microns, as observed, for example, by scanning electron microscope. The amount of particles, such as boron nitride, may be from 40 wt%, 50 wt%, or 60 wt%, up to 90 wt%, up to 85 wt%, up to 80 wt%, or up to 75 wt%, based on the total weight of the conductive polymer and polymer matrix material.

[0018] The polymer matrix material may include a first material selected from one or more of vinyl silicone resin, polyisobutylene polymer, organic silicone rubber, polyurethane, methyl methacrylate, organopolysiloxane, acrylate, and polyamide resin, preferably organic silicone rubber, and a second material selected from petroleum-based resin, silicone resin such as MQ silicone resin, polyol, ethyl acrylate, rosin, and ethylene phenyl acetate resin, preferably silicone resin. When the polymer matrix includes, for example, organic silicone rubber and silicone resin, the polymer matrix may include, for example, 2 to 80, preferably 15 to 35, weight percent silicone resin and 20 to 98, preferably 65 to 85, weight percent silicone rubber, based on the total weight of the polymer matrix.

[0019] Optionally, a support structure such as a thin film or nonwoven fabric can be used. The combination of conductive particles and polymer matrix can be applied to or impregnated into the support structure. If a support is used, it can have a thickness of, for example, 5 or 10 up to 40 or up to 30 microns. If a support is used, the thermal conductivity can vary through the thickness of the subpad.

[0020] Polishing pads as disclosed herein can provide desirable polishing characteristics (e.g., one or more of a desired removal rate, polishing consistency across the diameter of the pad, low defects, and polishing consistency when used to polish a series of substrates). For example, embodiments in which a polishing pad includes a thermally conductive subpad and grooves in the upper pad can provide a pad with relatively low thermal resistance and good thermal conductivity. These pads can facilitate thermal management at the polishing surface. For example, with polishing pads as disclosed herein, the polishing surface can heat and cool more slowly during conventional polishing, which can provide a more stable temperature profile at the polishing surface during polishing. When using a heated or cooled platen, such as a water-heated or water-cooled platen, the polishing surface can heat or cool more quickly. In summary, the pads of the present invention can optionally facilitate heat transfer through the pad when using a temperature-controlled device, such as a temperature-controlled platen. This can lead to more consistent removal rates. In addition, the thermal conductivity of the subpad can enhance the effectiveness of a thermal control system integrated into the platen of a polishing device by facilitating heat transfer through the pad.

[0021] The polishing pad as disclosed herein can be made, for example, by first forming a polishing layer. Then, a subpad layer is applied to the polishing layer. For example, the subpad layer can be attached to the polishing layer interface using an adhesive. Alternatively, a subpad precursor composition containing a thermally conductive polymer in a matrix material precursor can be applied to the polishing layer interface and then cured. The groove processing of the polishing layer is usually performed after the formation of the polishing layer / subpad layer stack, and when the groove is expanded, 100% of the thickness of the polishing layer should occur after the formation of the polishing layer / subpad layer stack. [Example]

[0022] Example 1 Various subpad materials were evaluated for modulus and strain under compression using the procedures described herein. The control subpad material was a porous polyurethane on a nonwoven support used in certain commercially available polishing pads. Other subpad materials useful in the pads disclosed herein were various thicknesses of a material containing boron nitride in a silicone matrix on a nonwoven substrate. The subpad materials used in the pads of the present invention exhibit significantly different strain behavior, as shown in Figure 4. The modulus for the samples is shown in Table 1 below.

[0023] [Table 1]

[0024] Example 2 Pads with both radial and concentric groove patterns were tested for polishing performance, and the results are shown in Table 2.

[0025] [Table 2]

[0026] Example 3 Various subpad compositions combined with various upper pad (polishing layer) thicknesses were evaluated to determine the thermal resistance through the pad. In each example shown in Table 1, the subpad was 50 mil (1.27 mm) thick and comprised 20 and 30 mil (0.51 and 0.76 mm) layers bonded together with an adhesive, and the upper pad was a porous polyurethane-based material. The subpad composition (and resulting subpad conductivity) and upper pad (polishing layer) thickness were varied. Samples 1A-1D and 2A-2D, which have subpad materials with low thermal conductivity, have high thermal resistance regardless of the upper pad thickness. When the thermal conductivity of the subpad material is high, as in Samples 3A-D, 4A-D, and 5A-D, the thickness of the upper pad affects the thermal resistance of the pad structure. This indicates that a combination of a relatively high thermal conductivity subpad material and recesses extending to or close to the subpad material to achieve the desired heat transfer characteristics in the pad can provide good thermal management capabilities in the pad. Notably, for top pad thicknesses above approximately 1 mm, there is little difference in thermal resistance for pads with subpad conductivities ranging from 5 to 34 W / mK. A similar trend was observed for subpad thicknesses of 20 mils (0.508 mm).

[0027] [Table 3]

[0028] Example 4 The polishing pads were prepared using a double-sided pressure-sensitive adhesive to secure the subpad to the polishing layer. The control pad was a commercially available pad with a porous polyurethane subpad on a nonwoven support. The thermal conductivity of this subpad was approximately 0.02 W / mK. Inventive Pads F and G used a boron nitride-containing nonporous subpad on a nonwoven support with a thermal conductivity of approximately 5 W / mK. The groove pattern was consistent throughout the samples, but the grooves on Inventive Pad F did not expose the underlying subpad, while the grooves on Inventive Pad G did expose the underlying subpad.

[0029] The pad was placed on a platen, brought into contact with the wafer, and rotated. Hot water (approximately 50°C) was applied to the pad surface for 3 minutes, followed by room temperature water for 3 minutes. The surface temperature was monitored with an IR gun. The data showed that the temperature of the polishing layer surface of the control pad rose more rapidly and reached a higher value during the application of hot water compared to Pads F and G of the present invention. However, when room temperature water was applied, the control pad cooled to a lower level more rapidly than Pads F and G of the present invention. This indicates that pads of the present invention may be effective in mitigating temperature fluctuations during polishing. Similarly, for Pad F, which had grooves that did not expose the subpad, the temperature of the polishing layer surface rose more rapidly and reached a higher value during the application of hot water compared to Pad G of the present invention, where the grooves reached the subpad layer, and when room temperature water was applied, Pad F of the present invention cooled to a lower level more rapidly than Pad G of the present invention.

[0030] Example 5 A control pad with a porous subpad of polyurethane impregnated on a nonwoven fabric (with a thermal conductivity of 0.02 W / mK) and a pad of the present invention with a boron nitride subpad in a silicone matrix composition (with a thermal conductivity of 5 W / mK) were each tested by polishing a series of wafers. A pressure-sensitive adhesive bonded the subpad to the polishing layer. The pad of the present invention showed a significant increase in removal rate with wafer count, while showing less variation than the control pad. This is consistent with the temperature data, as the control equilibrated quickly and was largely stable, while the pad of the present invention required several wafers to reach a temperature plateau. This demonstrates that polishing performance can be affected by changing the temperature in a pad as disclosed herein.

[0031] The present disclosure further encompasses the following aspects.

[0032] Aspect 1: A polishing pad for chemical mechanical polishing, comprising: a polishing layer having a polishing surface and a polishing-layer interface facing the polishing surface, the polishing layer comprising a polishing material; a subpad layer having a subpad interface adjacent to the polishing-layer interface and a bottom surface facing the subpad interface, the subpad layer comprising a subpad material; wherein the subpad layer has an average modulus of elasticity of 1 to 5 MPa under compression at a pressure of 24 to less than 48 kPa, an average modulus of elasticity of 5 to 20 MPa under compression at a pressure of 48 to 76 kPa, and a true strain of 10% or less at a maximum compression pressure of 1.2 MPa.

[0033] Embodiment 2: The polishing pad of embodiment 1, wherein the subpad layer is non-porous.

[0034] Embodiment 3: The polishing pad of embodiment 1 or 2, wherein the subpad material comprises a particulate filler in a polymer matrix material.

[0035] Aspect 4: The polishing pad of claim 3, wherein the particulate filler is an inorganic material.

[0036] Aspect 5: The polishing pad of claim 3, wherein the particulate filler is a thermally conductive material.

[0037] Aspect 6: The polishing pad of claim 3, wherein the particulate filler is present in an amount of 40 to 90, preferably 45 to 85, and more preferably 50 to 80 weight percent based on the total weight of the particulate filler and the polymer matrix material.

[0038] Embodiment 7: The polishing pad of any one of Embodiments 3-6, wherein the polymer matrix material comprises a silicone composition.

[0039] Embodiment 8: The polishing pad of embodiment 7, wherein the silicone composition comprises 2 to 80 weight percent of the silicone adhesive and 20 to 98 weight percent of the silicone rubber, based on the total weight of the silicone composition.

[0040] Embodiment 9: The polishing pad of any one of Embodiments 3-8, wherein the subpad material is provided on a woven or nonwoven material scaffold.

[0041] Embodiment 10: The polishing pad of any one of Embodiments 3-9, wherein the particulate filler is boron nitride.

[0042] Embodiment 11: The polishing pad of any one of the preceding embodiments, wherein the subpad material has a thermal conductivity of at least 1, preferably 1 to 35, more preferably 2 to 20, and even more preferably 2 to 10 Watts / mK.

[0043] Embodiment 12: The polishing pad of any one of the preceding embodiments, wherein the polishing layer has recesses that extend to a depth of at least 80%, preferably at least 90%, and more preferably at least 100% of the thickness of the polishing layer.

[0044] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., the range "up to 25% by weight, more specifically 5% to 20% by weight" includes the endpoints and all intermediate values ​​in the range "5% to 25% by weight," etc.). Additionally, listed upper and lower limits can be combined to form ranges (e.g., "at least 1% by weight or at least 2% by weight" and "up to 10% or 5% by weight" can be combined to form the ranges "1 to 10% by weight," "1 to 5% by weight," "2 to 10% by weight," or "2 to 5% by weight").

[0045] The present disclosure can comprise, consist of, or consist essentially of any suitable components disclosed herein. The present disclosure can additionally or alternatively be formulated to be free or substantially free of any components, materials, ingredients, adjuvants, or species used in prior art compositions or that are not necessary to achieve the function and purpose of the present disclosure.

[0046] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety, except that if a term in an incorporated reference conflicts or conflicts with a term in the present application, the term in the present application takes precedence over the conflicting term in the incorporated reference.

[0047] Unless otherwise specified herein, all test standards are the latest standards in effect as of the filing date of this application or, if priority is claimed, as of the filing date of the earliest priority application in which the test standard appears. [Explanation of symbols]

[0048] 1 polishing pad 10 Polishing layer 12 Upper polished surface 14 Recess 16 Polishing layer interface 20 Subpad Layer 22 Bottom of subpad 26 Subpad Interface 100 End Point Detection Window

Claims

1. 1. A polishing pad for chemical mechanical polishing, comprising: a polishing layer having a polishing surface and a polishing-layer interface facing the polishing surface, the polishing layer comprising an abrasive material; a subpad layer having a subpad interface adjacent the polishing layer interface and a bottom surface opposite the subpad interface, the subpad layer comprising a subpad material; The polishing pad, wherein the subpad layer has an average modulus of elasticity of 1 to 5 MPa under compression at a pressure of 24 to less than 48 kPa, an average modulus of elasticity of 5 to 20 MPa under compression at a pressure of 48 to 76 kPa, and a true strain of 10% or less against a maximum compression pressure of 1.2 MPa.

2. The polishing pad of claim 1 , wherein the subpad layer is non-porous.

3. The polishing pad of claim 2 , wherein the subpad layer comprises a particulate filler in a polymer matrix material.

4. The polishing pad of claim 3 , wherein the particulate filler is an inorganic material.

5. The polishing pad of claim 3 , wherein the particulate filler is a thermally conductive material.

6. 4. The polishing pad of claim 3, wherein the particulate filler is present in an amount of 40 to 90 weight percent based on the total weight of the particulate filler and polymer matrix material.

7. The polishing pad of claim 3 , wherein the polymer matrix material comprises a silicone composition.

8. 8. The polishing pad of claim 7, wherein the silicone composition comprises 2 to 80 weight percent silicone adhesive and 20 to 98 weight percent silicone rubber, based on the total weight of the silicone composition.

9. 4. The polishing pad of claim 3, wherein the subpad material is provided on a woven or nonwoven material scaffold.

10. 6. The polishing pad of claim 5, wherein the particulate filler is boron nitride.

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