Chemical mechanical polishing pad with disulfide bonds
By using disulfide bond-containing polyurethane matrix material in CMP pads, the problem of easy decomposition of existing CMP pads under high temperature and high mechanical stress is solved, achieving longer life and more stable polishing performance.
Patent Information
- Application Number
- CN202380067799.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-09-22
- Filing Date
- 2023-09-21
- Publication Date
- 2025-05-27
AI Technical Summary
Existing chemical mechanical polishing (CMP) pads are prone to decomposition under high temperatures and high mechanical stresses, resulting in shortened life and unstable performance.
An improved CMP pad is made of a material containing disulfide bonds in a polyurethane matrix, which can undergo chain exchange reactions at high temperatures, resulting in bond rearrangement rather than breaking, thereby improving the self-restorability of the shim.
The improved CMP pads exhibit longer service life and more stable polishing properties under CMP conditions and are able to perform continuously at higher removal rates and longer service periods.
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Figure CN120051356A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to chemical mechanical polishing pads, and more particularly to chemical mechanical polishing pads having disulfide bonds. Background Art
[0002] Integrated circuits are typically formed on a substrate by sequential deposition of conductive, semiconductive, and / or insulating layers on a silicon wafer. Various manufacturing processes require polishing or planarization of at least one of these layers on the substrate. For example, for certain applications (e.g., polishing a metal layer to form vias, plugs, and lines in trenches of a patterned layer), the overlying layer is planarized until the upper surface of the patterned layer is exposed. In other applications (e.g., polishing of a dielectric layer for photolithography), the overlying layer is polished until a desired thickness remains on the underlying layer. Chemical mechanical polishing (CMP) is a method of surface planarization. This method generally involves mounting a substrate on a carrier head. The exposed surface of the substrate is typically placed against a polishing pad on a rotating platen. The carrier head provides a controllable load (e.g., a downward force) on the substrate to push the substrate against the rotating polishing pad. A polishing liquid (such as a slurry having abrasive particles) may also be deposited on the polishing pad surface during polishing. Summary of the Invention
[0003] CMP pads experience significant thermal and mechanical stresses during the CMP process. These stresses can cause decomposition of conventional CMP pad materials, resulting in reduced CMP pad life and reduced and / or inconsistent performance over time. The present disclosure provides an improved CMP pad made of a material having disulfide bonds in a polyurethane matrix. The disulfide bonds may include disulfide bonds that can undergo a chain exchange reaction at the temperature experienced during the chemical mechanical polishing process, resulting in rearrangement of nearby disulfide bonds rather than breakage of these bonds during the chemical mechanical polishing process. The improved CMP pad has increased life and improved polishing performance under CMP conditions (i.e., at high temperature and high mechanical stress). The improved CMP pad of the present disclosure may have an increased material removal rate compared to those achieved by prior CMP pads, and these increased removal rates may persist over a longer usage period of the improved CMP pad.
[0004] In one embodiment, a precursor for preparing a chemical mechanical polishing pad includes a prepolymer, a disulfide-containing component, and a curing agent. Additionally, the prepolymer may be a prepolymer of polyurethane. The prepolymer may include a polyisocyanate. The prepolymer may include polytetrahydrofuran and toluene diisocyanate. The mass % of the prepolymer is in the range of 60% to 80%. The disulfide-containing component may include 2-hydroxyethyl disulfide. The mass % of the disulfide component may be in the range of 2.5% to 7.5%. The curing agent may be dimethylthiotoluenediamine. The precursor may further include one or more porous fillers.
[0005] In another embodiment, a chemical mechanical polishing pad includes a polishing surface, wherein the polishing surface includes a material comprising disulfide bonds in a polymer matrix. Additionally, the polymer matrix can be a polyurethane matrix. The material comprising the disulfide bonds can include disulfide bonds that can undergo a chain exchange reaction at the temperature experienced during a chemical mechanical polishing process, resulting in bond rearrangement during the chemical mechanical polishing process.
[0006] In yet another embodiment, a method of preparing a chemical mechanical polishing pad includes the steps of: preparing a precursor by combining a prepolymer, a disulfide-containing component, and a curing agent; casting the precursor at a first temperature; and curing the cast precursor at a second temperature. Additionally, the method can further include mixing the combined prepolymer, disulfide-containing component, and curing agent for less than 1 minute before casting the precursor. The first temperature can be greater than the second temperature. The method can further include combining the prepolymer with one or more additives such as a porous filler. Additionally, the prepolymer can be a prepolymer of polyurethane. The prepolymer can include a polyisocyanate. The prepolymer can include polytetrahydrofuran and toluene diisocyanate. The mass % of the prepolymer is in the range of 60% to 80%. The disulfide-containing component can include 2-hydroxyethyl disulfide. The mass % of the disulfide component can be in the range of 2.5% to 7.5%. The curing agent can be dimethylthiotoluenediamine. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] To assist in understanding the present disclosure, reference will now be made to the following description in conjunction with the accompanying drawings, in which:
[0008] Figure 1 is a diagram of an exemplary system for chemical mechanical polishing (CMP);
[0009] Figure 2 is a reaction diagram of an exemplary reaction for preparing a CMP pad having disulfide bonds and a polyurethane matrix;
[0010] Figure 3 is a reaction diagram of an exemplary thermally induced transformation of the disulfide-containing component of a CMP pad during use of the CMP pad;
[0011] Figure 4 is for preparing a Figure 1 is a block diagram of an exemplary composition of a precursor for a CMP pad for use in a system;
[0012] Figure 5 is a flow chart of an exemplary process for preparing a CMP pad;
[0013] Figure 6Graphs of removal rates achieved by the CMP pads improved by the present disclosure and prior CMP pads under different polishing conditions;
[0014] Figure 7 and 8 Graphs of removal rates achieved by different CMP pads improved by the present disclosure using different polishing slurries; and
[0015] Figure 9 and 10 Graphs of CMP pad temperature and torque achieved using the CMP pads improved by the present disclosure and prior CMP pads respectively during the polishing process. Detailed Description
[0016] It should be understood at the outset that although the following describes exemplary implementations of embodiments of the present disclosure, the present disclosure may be implemented using any number of techniques, whether currently known or unknown. The present disclosure should in no way be limited to the exemplary specific implementations, figures, and techniques described below. Additionally, the figures are not necessarily drawn to scale.
[0017] The present disclosure recognizes that conventional materials used to prepare CMP pads suffer from insufficient lifetimes due to wear and degradation of the CMP pads during their use in the CMP process. For example, prior polyurethane-based CMP pads wear and degrade during CMP processes that experience severe mechanical and thermal stresses. The high surface temperatures experienced during the CMP process can cause decomposition of prior CMP pads, resulting in performance loss and reduced useful life. The present disclosure provides improved CMP pads having self-recovery properties. The CMP pads of the present disclosure are prepared from a precursor comprising a disulfide component together with a prepolymer and a curing agent. The disulfide bonds in the resulting material can undergo a chain exchange reaction at the temperatures experienced during the CMP process, resulting in bond rearrangement rather than bond breakage during the CMP process. This rearrangement promotes improved CMP pad performance and lifetime.
[0018] Chemical Mechanical Polishing (CMP) System
[0019] Figure 1 A system 100 for performing chemical mechanical polishing is described. System 100 includes a CMP pad 102 (also referred to as a "polishing pad") that is placed on or attached to a platen 104. For example, an adhesive layer (not shown) may be used to attach the polishing pad to the platen 104. The platen 104 generally rotates during chemical mechanical polishing. A wafer 106 (e.g., a silicon wafer with or without a conductive layer, a semiconductive layer, and / or an insulating layer as described above) is attached to the head 108 of a rotatable chuck. The wafer 106 may be attached using a vacuum and / or a reversible adhesive (e.g., an adhesive that holds the wafer 106 in place during chemical mechanical polishing but allows the wafer 106 to be removed from the head 108 after chemical mechanical polishing). As Figure 1As described, pressure can be applied to the wafer 106 during chemical mechanical polishing (e.g., to facilitate contact between the surface of the wafer 106 and the CMP pad 102). As further described below, the improved CMP pad 102 of the present disclosure may allow for effective polishing with reduced applied downward pressure.
[0020] In the following Figure 2 and 3 an exemplary polishing pad 102 is described, along with the chemical reactions associated with the formation and restoration of the CMP pad 102 during a CMP process. Still referring to Figure 1 , the CMP pad 102 generally has a circular or approximately cylindrical shape (i.e., having an upper surface, a lower surface, and a curved edge). As described in more detail with respect to the following Figures 2 to 10 , at least one upper polishing surface of the CMP pad 102 comprises a matrix of polyurethane chains linked by disulfide bonds. The following with respect to Figure 2 and 4 more particularly describes exemplary compositions of precursors for preparing the exemplary polishing pad 102. The CMP pad 102 can have a suitable thickness and any suitable diameter (e.g., to be employed in a CMP system such as system 100). For example, the thickness of the CMP pad 102 can range from about 0.5 millimeters to greater than 5 centimeters. In some embodiments, the thickness of the polishing pad can be in the range of 1 millimeter to 5 millimeters. Any suitable manufacturing process can be used to prepare the polishing pad 102, including (e.g.) casting-based manufacturing processes, additive manufacturing processes, etc. The polishing pad diameter can be selected to match or be just less than the diameter of the platen 104 of the polishing system 100 being used. The CMP pad 102 generally has a uniform thickness (e.g., the variation across the radial extent of the polishing pad is no more than 50%, 25%, 20%, 10%, 5% or less of the thickness).
[0021] A slurry 110 can be provided on the surface of the CMP pad 102 before and / or during chemical mechanical polishing. The slurry 110 can be any suitable slurry for polishing the type of wafer and / or layer material to be planarized (e.g., to remove a silicon oxide layer from the surface of the wafer 106). The slurry 110 generally comprises a fluid and abrasive and / or chemically reactive particles. Any suitable slurry 110 can be used. For example, the slurry 110 can react with one or more materials being removed from the surface being planarized. The improved CMP pad 102 of the present disclosure promotes both higher removal rates and longer lifetimes, even in more aggressive slurries (such as W8902-CI45), which can achieve relatively high temperatures during polishing.
[0022] Regulator 112 is a device configured to condition the surface of CMP pad 102. Regulator 112 generally contacts the surface of CMP pad 102 during chemical mechanical polishing and removes a portion of the upper layer of CMP pad 102 to improve its performance. For example, regulator 112 can roughen the surface of CMP pad 102. Certain embodiments of the polishing pads described in the present disclosure provide a reduced need for conditioning and improved resilience to repeated conditioning, such that CMP performance can be maintained with fewer or shorter conditioning steps and even the CMP pad life can be maintained after multiple rounds of conditioning.
[0023] Exemplary CMP Pad
[0024] Figure 2 Exemplary CMP pad 102 is shown in more detail. Exemplary CMP pad 102 includes an upper polishing surface 212, which may include grooves and / or channels that can facilitate the movement of slurry (e.g., Figure 1 slurry 110) away from surface 212 during the CMP process. At least the upper polishing surface 212 includes a material 206, which includes a matrix of polymers 208a,b having disulfide bonds 210. Disulfide bonds 210 are sulfur-sulfur bond coupling chains of polymers 208a,b, as illustrated in the exemplary chemical structures shown in Figure 2 . As further described below Figure 3 , the sulfur-sulfur bonds of disulfide bonds 210 can undergo reactions at elevated temperatures, which improves the resilience of material 206, resulting in a self-healing CMP pad 102 with improved useful life and performance.
[0025] Material 206 can be prepared via reaction 200. In reaction 200, a prepolymer 202 reacts with a disulfide-containing component 204. Prepolymer 202 can be a polyisocyanate, such as toluene diisocyanate, as shown in the examples of Figure 2 . Disulfide-containing component 204 can be 2-hydroxyethyl disulfide, as shown in the examples of Figure 2 . Further details and examples of the components for preparing the precursors of CMP pad 102 are described below with respect to Figure 4 and 5 .
[0026] Figure 3 Illustrates an exemplary thermal activation reaction of molecules 302a,b of material 206 of exemplary CMP pad 102 during the CMP process. As described above, CMP pads (such as CMP pad 102) experience elevated temperatures during the CMP process. Prior polymeric CMP pad materials can decompose at these elevated temperatures (e.g., at least in part due to thermally induced bond breakage). In contrast, the disulfide bonds 210 of the improved CMP pad material 206 impart self-healing properties to CMP pad 102.
[0027] For example, as shown in Figure 3As shown in reaction 300, molecules 302a and 302b of the initial CMP pad material 206 can undergo a radical-mediated reaction that involves the hemolytic cleavage of the disulfide bond 210, followed by subsequent radical transfer of the sulfur radicals to form new molecules 302c and 302d of the thermally rearranged material 206'. Thus, rather than decomposing, molecules 302a,b transfer polymer chains to form similar molecules 302c and 302d, such that the structure of the CMP pad 102 undergoes less decomposition at increased temperatures. This can promote improved performance and increased useful life of the CMP pad 102 compared to previous CMP pads. For example, the microscale texture of the CMP pad 102 can be more effectively maintained at high temperatures because the bonds are rearranged via reaction 300 rather than being broken. In some cases, the CMP pad 102 can be used to remove materials involving high CMP temperatures, such as tungsten.
[0028] Exemplary CMP pad precursor
[0029] Figure 4 An exemplary precursor 400 for preparing the CMP pad 102 is shown. The precursor 400 includes a prepolymer 402, a disulfide-containing component 404, a curing agent 406, and optional one or more additives 408. The precursor 400 is an example and may include more or fewer components to meet the requirements of a given application.
[0030] The prepolymer 402 can be a curable polyurethane prepolymer. As an example, the prepolymer 402 can be a toluene diisocyanate (TDI) prepolymer. For example, the TDI prepolymer can be based on polytetrahydrofuran (PTMEG), polyester, or PTMEG / polyester. The prepolymer 402 can be a polyisocyanate, such as toluene diisocyanate. Examples of this prepolymer 402 are Imuthane PET-75D from Coim International and 80DPLF from Anderson Development Company. Another exemplary prepolymer 402 is Figure 2 prepolymer 202. In some cases, the precursor 400 includes 60% to 80% by weight of the prepolymer 402. However, the prepolymer 402 can be added at a lower or higher concentration as appropriate for a given application.
[0031] The disulfide-containing component 404 is a component having a disulfide or sulfur-sulfur bond. Exemplary disulfide-containing components are the above Figure 2The disulfide-containing component 204 described in [reference]. For example, the disulfide-containing component can be 2-hydroxyethyl disulfide. In some cases, the precursor 400 contains 2.5% to 7.5% by weight of the disulfide-containing component 404. The precursor 400 can contain 3.5% to 6.5% by weight of the disulfide-containing component 404. The precursor 400 can contain 5% to 6% by weight of the disulfide-containing component 404. Examples of the disulfide-containing component 404 include (but are not limited to) allyl disulfide, 3,3'-dihydroxydiphenyl disulfide, 4-aminophenyl disulfide, penicillamine disulfide, bis(2-methacryloyloxyethyl) disulfide, bis(16-hydroxyhexadecyl) disulfide, 4-nitrophenyl disulfide, bis(4-methoxyphenyl) disulfide, bis(10-carboxydecyl) disulfide, 2-(salicylideneamino)phenyl disulfide, and N,N'-bis(2-hydroxy-benzylidene)-4-aminophenyl disulfide.
[0032] The curing agent 406 is used to initiate the polymerization of the prepolymer 402. In some cases, the curing agent 406 can initiate or promote this reaction at an elevated temperature. As an example, the curing agent 406 can be dimethylthiotoluenediamine (DMTDA). The precursor 400 can contain 5% to 20% by weight of the curing agent 406. 10 to 20%. However, the curing agent 406 can be added at a lower or higher concentration as appropriate for a given application. Examples of the curing agent 406 include (but are not limited to) diamines such as 4,4'-methylenebis(orthochloroaniline), 2,6-diethyl-3-chloroaniline, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, and methylenebis(orthoethylaniline); and diols such as hydroquinone bis(2-hydroxyethyl) ether, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,3-propanediol, and 1,6-hexanediol.
[0033] One or more additives 408 can include stabilizers, plasticizers, porous fillers, pigments, etc. For example, the porous filler is a particle (e.g., a microsphere) that expands in volume when heated. The porous filler can cause the formation of pores in the polishing pad, which can improve the pad performance by creating a porous structure in the polymer matrix formed by curing the prepolymer 402. Another exemplary additive 408 is carbon black, which is a substance that adds color to the formed CMP pad 102. The additive 408 is typically added at 1% to 30% by weight. For example, the additive can be included between 1% and 5% by weight. However, the additive 408 can be added at a lower or higher concentration as appropriate for a given application. In some cases, the precursor 400 does not contain the additive 408.
[0034] Exemplary method for preparing a CMP pad
[0035] Figure 5 Describe an exemplary method 500 for preparing a CMP pad 102 according to illustrative embodiments of the present disclosure. Method 500 may begin at step 502, where prepolymer 402 is combined with one or more additives 408. For example, prepolymer 402 and additive 408 may be combined and mixed for a period of time. As an example, prepolymer 402 and additive 408 may be combined and mixed at 160°F for about 2 hours.
[0036] At step 504, the mixture from step 502 is combined with a disulfide component 404 and a curing agent 406. The resulting mixture may be simply mixed (e.g., for about 1 minute or less), after which step 506 is continued, where the resulting mixture (i.e., Figure 4 precursor 400) is cast to prepare CMP pad 102. As an example, precursor 400 may be cast at 260°F for about 10 minutes.
[0037] At step 508, the cast precursor 400 is cured for a period of time at a suitable temperature for curing precursor 400. The curing of step 508 may be carried out at the same or a different temperature than the temperature used for casting in step 506. In some cases, the curing may be carried out at a lower temperature than that used for casting. For example, the cast precursor 400 may be cured at 200°F for about 12 hours. The resulting CMP pad 102 may be used in a CMP pad process as described in the examples regarding Figure 1 above.
[0038] Experimental Examples
[0039] Different exemplary CMP pads (Samples 1 to 3) were prepared using the precursors improved by the present disclosure, and their performances were compared with a control CMP pad. Table 1 below shows the compositions of the improved CMP pad Samples 1 to 3 and the control CMP pad. The prepolymer is PTMEG-based TDI (Imuthane PET-75D from Coyne International for the control CMP pad and 80DPLF from Anderson Development for Samples 1 to 3). The disulfide component is 2-hydroxyethyl disulfide from Sigma-Aldrich. The curing agent is DMTDA (Curene 107 from Anderson Development). The boron nitride powder additive is NX1 powder 25Lb Ctr from Momentive Performance Materials. The porous filler additive is Expancel 461DE20 d70 from Nouryon Pulp and Performance Chemicals LLC.
[0040] Table 1: Composition of precursors used to prepare the CMP pad samples tested.
[0041]
[0042] Figure 6 Showing the tungsten (W) coating removal rates achieved under different conditions of in-situ adjustment amount (i.e., relative duration of the adjustment steps performed), adjustment downforce ("regulator_df", i.e., the force applied during adjustment, in psi), and polishing time (in seconds) by sample 2 CMP pad and control CMP pad. The sample 2 CMP pad achieves higher removal rates under milder adjustment conditions than those desired for the control CMP pad. Thus, the sample 2 CMP pad should provide improved performance during a longer CMP pad life while also consuming less material for the adjustment steps (e.g., because the adjustment steps can be shortened and / or performed less frequently). Comparison of tungsten removal rates. The sample 2 CMP pad achieves higher removal rates under milder adjustment conditions than those desired for the control CMP pad. Thus, the sample 2 CMP pad should provide improved performance during a longer CMP pad life while also consuming less material for the adjustment steps (e.g., because the adjustment steps can be shortened and / or performed less frequently).
[0043] Figure 7 Showing the tungsten removal rates of sample 1 CMP pad and control CMP pad in two different chemical mechanical polishing slurries (W7300 - B21 and W8902 - CI45). W8902 - CI45 is a more aggressive slurry that can remove tungsten more effectively but can also cause an increased temperature to be reached during polishing. As Figure 7 shown, specifically, when using W8902 - CI45, the sample 1 CMP pad shows a higher removal rate than the control CMP pad. This further confirms the improved performance of the CMP pads of the present disclosure for tungsten removal.
[0044] Figure 8 Showing the tungsten removal rates of sample 2 and 3 CMP pads and control CMP pad in two different chemical mechanical polishing slurries (W7300 - B21 and W8902 - CI45). As Figure 8 shown, when using W8902 - CI45, the sample 2 and 3 CMP pads show higher removal rates than the control CMP pad.
[0045] Figure 9 and 10 each showing the temperature and torque achieved using the control CMP pad and sample 1 CMP pad for tungsten removal during the CMP process. The sample 1 CMP pad can operate effectively at higher temperatures and torques than the control CMP pad. This ability to operate consistently and well at higher temperatures and torques can be at least partially imparted by the self - recovering nature of the CMP pads of the present disclosure, as (for example) described above Figure 3 stated.
[0046] Modifications, additions, or omissions may be made to the systems, devices, and methods described herein. Components of the systems and devices may be integrated or separated. Additionally, the operations of the systems and devices may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Further, the steps may be performed in any suitable order. Additionally, the operations of the systems and devices may be performed using any suitable logic. As used in this document, "each" refers to each member of a group or each member of a subset of a group.
[0047] As used herein, unless the context clearly dictates otherwise or is otherwise specified, "or" is inclusive and not exclusive. Thus, unless clearly dictated otherwise or the context is otherwise specified, herein, "A or B" means "A, B, or both." Further, unless clearly dictated otherwise or the context is otherwise specified, "and" is both conjunctive and respective. Thus, unless clearly dictated otherwise or the context is otherwise specified, herein, "A and B" means "A and B, conjunctively or respectively."
[0048] The scope of the present disclosure includes all variations, substitutions, modifications, alterations, and improvements of the exemplary embodiments described or illustrated herein that would be understood by those of ordinary skill in the relevant art. The scope of the present disclosure is not limited to the exemplary embodiments described or illustrated herein. Additionally, although the present disclosure describes and illustrates each of the embodiments herein as including particular components, elements, features, functions, operations, or steps, any of these embodiments may include any combination or arrangement of any of the components, elements, features, functions, operations, or steps described or illustrated elsewhere herein that would be understood by those of ordinary skill in the relevant art. Further, in the appended claims, a device or system or a component of a device or system that is recited as being adapted, arranged, capable, constructed, enabled, operable, or operative to perform a particular function includes the device, system, component, whether or not the particular function is activated, turned on, or disclosed, so long as the device, system, or component is so adapted, arranged, capable, constructed, enabled, operable, or operative. Additionally, although the present disclosure describes or illustrates particular embodiments as providing particular advantages, a particular embodiment may provide none, some, or all of these advantages.
[0049] Unless otherwise specified herein or clearly contradicted by the context, the use of the terms "a / an" and "the" and similar references in the context of describing the present disclosure (especially in the context of the following claims) shall be construed to cover both the singular and the plural. Unless otherwise specified, the terms "comprising," "having," "including," and "containing" shall be construed as open-ended terms (i.e., meaning "including but not limited to"). Unless otherwise specified herein, the recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, and each separate value is incorporated into the specification as if it were individually recited herein. The use of any and all examples or exemplary language (e.g., "such as") provided herein is merely intended to better explain the present disclosure and does not impose a limitation on the scope of the claims.
Claims
1. A precursor for preparing a chemical mechanical polishing pad, the precursor comprising: A prepolymer; A disulfide-containing component; and A curing agent.
2. The precursor according to claim 1, wherein the prepolymer is a prepolymer of polyurethane.
3. The precursor according to claim 1, wherein the prepolymer comprises a polyisocyanate.
4. The precursor according to claim 1, wherein the prepolymer comprises polytetrahydrofuran and toluene diisocyanate.
5. The precursor according to claim 1, wherein the mass % of the prepolymer is in the range of 60% to 80%.
6. The precursor according to claim 1, wherein the disulfide-containing component comprises 2-hydroxyethyl disulfide.
7. The precursor according to claim 1, wherein the mass % of the disulfide component is in the range of 2.5% to 7.5%.
8. The precursor according to claim 1, wherein the curing agent is dimethylthiotoluenediamine.
9. The precursor according to claim 1, which further comprises one or more porous fillers.
10. A chemical mechanical polishing pad, which comprises a polishing surface, wherein the polishing surface comprises a material containing disulfide bonds in a polymer matrix.
11. The chemical mechanical polishing pad according to claim 10, wherein the polymer matrix is a polyurethane matrix.
12. The chemical mechanical polishing pad according to claim 10, wherein the material containing the disulfide bonds comprises disulfide bonds that can undergo a chain exchange reaction at the temperature experienced during the chemical mechanical polishing process, thereby resulting in bond rearrangement during the chemical mechanical polishing process.
13. A method for preparing a chemical mechanical polishing pad, the method comprises: Preparing a precursor by combining a prepolymer, a disulfide-containing component and a curing agent; Casting the precursor at a first temperature; and Curing the cast precursor at a second temperature.
14. The method according to claim 13, which further comprises mixing the combined prepolymer, disulfide-containing component and curing agent for less than one (1) minute before casting the precursor.
15. The method according to claim 13, wherein the first temperature is greater than the second temperature.
16. The method according to claim 13, wherein the prepolymer comprises a polyisocyanate.
17. The method according to claim 13, wherein the mass % of the prepolymer is in the range of 60% to 80%.
18. The method according to claim 13, wherein the disulfide-containing component comprises 2-hydroxyethyl disulfide.
19. The method according to claim 13, wherein the mass % of the disulfide component is in the range of 2.5% to 7.5%.
20. The method according to claim 13, wherein the curing agent is dimethylthiotoluenediamine.