Chemical mechanical polishing pad with endpoint detection window, method of making and use thereof

Abstract

The present invention relates to a chemical mechanical polishing pad with an end point detection window, a method of making and using the same. The end point detection window has a "shoulder" at the interface with the polishing layer and the "shoulder" has a lower hardness than the window. The polishing pad window of the present invention avoids the liquid leakage and polishing defects problems of conventional polishing pads with windows during polishing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical mechanical polishing, and particularly relates to a chemical mechanical polishing pad with an endpoint detection window, a preparation method and application thereof. BACKGROUND

[0002] In the process of manufacturing integrated circuits, it is often necessary to eliminate the micro concave-convex on the wafer surface plated with different patterns and achieve planarization, and chemical mechanical polishing (CMP) is a common technology for polishing semiconductor wafers.

[0003] In CMP polishing, how to determine the polishing endpoint is a very important work, and in-situ methods for determining the polishing endpoint have been developed. In-situ optical endpoint indication technology can be divided into two basic categories: monitoring the reflected light signal of a single wavelength, such as light from a laser source, or monitoring the reflected light signal from multiple wavelengths. When monitoring the light signal, the reflectivity of the substrate changes as the composition at the surface of the substrate changes from one material to another. This change in reflectivity is used to detect the CMP polishing endpoint.

[0004] Patent CN102161182B proposes an anti-creep polishing pad window, which improves the cross-linking degree by designing the window formula, thereby improving the anti-creep property of the window, so that the window does not cause large deformation during polishing, thereby improving the stability problem of the window.

[0005] Patent CN108723983B discloses an aliphatic polyurethane optical endpoint detection window and a CMP polishing pad containing them. The patent prepares a detection window material that is more durable to use at a lower ultraviolet cutoff wavelength by designing the endpoint detection window formula.

[0006] However, during polishing, the chemical mechanical polishing pad is continuously extruded and moves relative to the polishing head, and the polishing pad will continuously deform slightly. Since the polishing pad and the endpoint detection window are not an integral whole, the polishing pad and the endpoint detection window will vibrate and deform at different frequencies, so there is a possibility that the polishing pad and the window will have a gap and cause liquid leakage, and the deformation of the window will eventually also affect the stability of the polished wafer. SUMMARY

[0007] To solve the problems existing in the prior art, the present application creatively starts from the structure of the polishing pad endpoint detection window itself and develops a new type of endpoint detection window, which can eliminate or reduce the polishing defects caused by window liquid leakage and deformation during polishing, thereby completing the present application.

[0008] Another object of the present application is to provide a method for preparing the chemical mechanical polishing pad with end-point detection window.

[0009] Another object of the present application is to provide the use of the chemical mechanical polishing pad with end-point detection window.

[0010] To achieve the above technical objects, the present application adopts the following technical solutions:

[0011] A chemical mechanical polishing pad with end-point detection window, comprising a polishing layer, a buffer layer, an adhesive layer and at least one end-point detection window, the end-point detection window has at least one "shoulder" on each of its two long sides, the "shoulder" extends into and is embedded in the polishing layer connected with the detection window, and the hardness variation rate of the window is not more than 20%, wherein the hardness variation rate of the window = (window hardness - "shoulder" hardness) / window hardness.

[0012] In a specific embodiment, the end-point detection window has an axial symmetric shape with long sides and short sides in a top view of the polishing pad, preferably a rectangular shape.

[0013] In a specific embodiment, the long sides of the end-point detection window are parallel to the diameter direction of the polishing pad, and the short sides are perpendicular to the diameter direction of the polishing pad.

[0014] In a specific embodiment, the "shoulder" of the end-point detection window is located on the long side of the detection window, preferably at the center of the long side; preferably, the "shoulder" of the end-point detection window has at least one of a rectangular shape, a square shape, a semicircular shape, a trapezoidal shape, and a zigzag shape in a top view, preferably a rectangular shape; more preferably, the width direction of the "shoulder" is parallel to the long side direction of the detection window, and the length direction of the "shoulder" is perpendicular to the long side direction of the detection window; preferably, 0 < SW ≤ 1 / 2L, 1 / 2L ≤ SL ≤ 2 / 3L, wherein L is the length of the long side of the detection window, SL is the length of the length direction of the "shoulder", and SW is the length of the width direction of the "shoulder".

[0015] In a specific embodiment, the thickness of the end-point detection window is the same as the thickness of the polishing layer, and the thickness of the "shoulder" of the window is ≤ 2 / 3 of the thickness of the window; preferably, the "shoulder" of the window is located below the surface of the polishing layer, preferably in the middle or lower part of the polishing layer.

[0016] In a specific embodiment, the surface of the polishing pad has grooves, wherein the circumferential grooves are truncated by the window at the position passing through the end-point detection window, and the grooves stop at the end position of the length direction of the "shoulder" of the window.

[0017] In a specific embodiment, the polishing layer is a polyurethane elastomer;

[0018] Preferably, the buffer layer is a polyurethane impregnated non-woven material.

[0019] Preferably, the adhesive layer is selected from pressure sensitive adhesives and / or reactive hot melt adhesives.

[0020] In another aspect, the method for preparing the chemical mechanical polishing pad with end point detection window as described above comprises the steps of successively curing to obtain the end point detection window with "shoulder" and the polishing layer, and then pasting and pressing the polishing layer with the buffer layer through the adhesive layer.

[0021] In a specific embodiment, the end point detection window with "shoulder" is obtained by reacting the prepolymer containing isocyanate groups with the active hydrogen groups, preferably the stoichiometric ratio of isocyanate groups to active hydrogen is 0.8-1.2, wherein the stoichiometric ratio of isocyanate groups to active hydrogen in the "shoulder" is 0.2-0.4 less than that in the main body of the detection window.

[0022] In a specific embodiment, the window main body and the "shoulder" are separately cast in a mold according to the proportion, and then placed in an oven at 70-100℃ for 30-60min to shape and demold, and then the "shoulder" and the main body are taken out respectively, and then the two are fixed in a curing mold at a pressure of not less than 10MPa for at least 12 hours, and then demolded to obtain the end point detection window with "shoulder".

[0023] In another aspect, the use of the chemical mechanical polishing pad with end point detection window as described above in chemical mechanical polishing.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] The end point detection window of the present application relies on its "shoulder" structure to form a physical insertion joint with the polishing layer. The risk of window falling off is reduced. At the same time, the "shoulder" of the window is located inside the polishing layer of the polishing pad, which can ensure that the slight deformation of the polishing layer and the end point detection window caused by pressure and rotation during polishing is of the same frequency, avoiding the deformation and liquid leakage of the window caused by different deformations, thereby avoiding the influence of poor polishing consistency.

[0026] The present application can ensure the firm connection between the window body and the "shoulder" position by controlling the hardness change rate of the window. If the hardness change rate of the window is too large, the hardness difference between the two is large, which will cause the cracking of the "shoulder" and the main body part, and the window body will be broken out during the polishing process. At the same time, in order to ensure the same polishing effect and less scratches when the wafer passes through the surface of the polishing layer with grooves and the surface of the window without grooves during the polishing process, the hardness uniformity on the entire polishing plane needs to be ensured. Since the polishing layer surface and the inside have a microporous structure, the overall hardness and compression rate will be slightly lower than the hardness and compression rate of the window part. In order to smoothly transition the hardness and compression rate when the polishing element passes through the window body area from the polishing layer surface during the polishing process, the hardness of the "shoulder" of the window is preferably slightly larger than the hardness of the polishing layer and smaller than the hardness of the main body part of the window. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a cross-sectional view of the polishing pad along the direction of the end point detection window of the present application.

[0028] Figure 2 is a top view of the polishing pad of the present application.

[0029] Figures 3 to 7 is a top view of the end point detection window with different shoulders of the polishing pad of the present application.

[0030] Figure 8 is a top view of the end point detection window with different shoulders of the polishing pad of the present application.

[0031] wherein 1 is the polishing layer, 2 is the buffer layer, 3 is the main body part of the end point detection window, and 4 is the "shoulder" of the end point detection window. DETAILED DESCRIPTION

[0032] The following examples will further illustrate the method provided by the present application, but the present application is not limited to the listed examples, and any other known changes within the scope of the claims of the present application should also be included.

[0033] As Figure 1As shown, one aspect of the present invention provides a chemical mechanical polishing pad with an endpoint detection window. The polishing pad has at least a polishing layer 1, a buffer layer 2, an adhesive layer (not shown in the figure), and an endpoint detection window (including a main body portion 3 and a "shoulder" 4 of the endpoint detection window). The endpoint detection window has at least one "shoulder" on each of its two long sides, which is inserted into the polishing layer connected to the detection window. The window hardness change rate should be less than or equal to 20%, for example, 0, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, etc., but not limited to these. The window hardness change rate is calculated as (window hardness - "shoulder" hardness) / window hardness, meaning the hardness at the "shoulder" of the window should be slightly greater than the hardness of the polishing layer and less than the hardness of the main body portion of the window.

[0034] like Figure 2 As shown, the shape of the window is a symmetrical figure, such as a rectangle, or it can be a rhombus, an oval, or other shapes. Preferably, it is a shape with a long side and a short side, and more preferably, it is a rectangular shape.

[0035] For a preferred embodiment, when the endpoint detection window is rectangular in top view on the polishing pad surface (e.g.) Figure 2 Its long side is parallel to the diameter of the polishing pad, and its short side is perpendicular to the diameter of the polishing pad.

[0036] Taking a rectangular top view of the endpoint detection window on the polishing pad surface as an example, the "shoulder" of the endpoint detection window is located along the long side of the detection window, preferably at the center of the long side, such as... Figure 3 As shown. The width (SW) of the "shoulder" is parallel to the long side of the detection window, and the length (SL) of the "shoulder" is perpendicular to the long side of the detection window.

[0037] Specifically, the length L of the long side of the window is 70-80 mm, for example, including but not limited to 70, 72, 74, 76, 78, 80 mm. The width W of the window is 40-60 mm, for example, including but not limited to 40, 45, 50, 55, 60 mm. The thickness T of the window is 1-3 mm, for example, including but not limited to 1, 1.5, 2, 2.5, 3 mm. The length and width of the shoulder portion satisfy 0 < SW ≤ 1 / 2L and 1 / 2L ≤ SL ≤ 2 / 3L, respectively. The thickness of the main body of the window is the same as the thickness of the polishing layer, and the thickness of the shoulder portion of the window is less than or equal to 2 / 3 of the thickness of the window. The "shoulder portion" of the detection window is inserted into the polishing layer, and the specific position is not particularly limited, which can be located in the upper, middle, lower or lower part of the polishing layer, as long as it is not exposed to the surface of the polishing layer. Those skilled in the art can understand that the "shoulder portion" of the end point detection window has a top view in the shape of a rectangle (in fact, it has a certain thickness and should be considered as a rectangular solid. For the sake of convenience, it is described by its top view). It can also be other patterns, such as square, triangle, trapezoid, zigzag and other deformed shapes, as shown in Figures 4 to 7 but not limited thereto. The "shoulder portion" of the end point detection window of the present application plays a role in being embedded in the polishing layer to further connect the window and the polishing layer closely, which is similar to the "mortise and tenon" structure in mechanical structure, so that the main body of the window and the "shoulder portion" are firmly connected and do not leak liquid due to gaps during polishing.

[0038] The polishing layer surface of the chemical mechanical polishing pad of the present application also has a groove shape, for example, a groove pattern selected from a curved groove, a linear groove, a perforation and a combination thereof. Preferably, the groove pattern comprises a plurality of grooves, and more preferably, the plurality of grooves is a concentric groove structure. The circumferential groove is truncated by the window at the end point detection window, and the groove stops at the maximum length of the shoulder portion of the window, as shown in Figure 8 .

[0039] The polishing layer material can refer to the prior art, for example, selected from a segment block copolymer comprising at least one hard segment and at least one soft segment, including polyethylene oxide, poly(ether ester) block copolymer, polyamide, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, polyacrylic acid, polymethacrylic acid, polyaspartic acid, styrene polymer, epoxy polymer, maleic anhydride methyl vinyl ether copolymer and combinations thereof.

[0040] The polishing layer material can also be selected from polyurethane elastomer, polyether elastomer, polyether polyester elastomer, polyamide-based elastomer, thermoplastic polyurethane, thermoplastic rubber, styrene-butadiene copolymer, silicone rubber, synthetic rubber, styrene-isoprene copolymer, styrene-ethylene-butylene copolymer and combinations thereof.

[0041] The cushioning layer material includes woven and non-woven materials, such as felted materials, spunbond materials, and needle punch materials. The materials of the cushioning layer in the present invention can include, for example, polymer impregnated felt materials (e.g., polyurethane impregnated felt materials) and woven materials (e.g., thick flannel materials).

[0042] The polishing pad in the present invention also includes an adhesive layer selected from a pressure sensitive adhesive, a reactive hot melt adhesive, or a mixture of both. The hot melt adhesive is selected from at least one of polyolefin, ethylene vinyl acetate, polyamide, polyester, polyurethane, polyvinyl chloride, or epoxy resin. The pressure sensitive adhesive is selected from at least one of an acryl-based adhesive (PSAV) or a rubber-based adhesive (PSA8). The main function of the adhesive layer is to tightly bond the polishing layer and the cushioning layer together.

[0043] The present invention also provides a method of making the end point detection window, comprising the steps of:

[0044] The end point detection window is obtained by reacting a prepolymer containing isocyanate groups with a polyol containing unreacted active hydrogen groups, wherein the stoichiometric ratio of isocyanate groups to active hydrogen groups in the main body of the end point detection window is 0.8 to 1.2, for example, including but not limited to 0.8, 0.9, 1.0, 1.1, 1.2. The stoichiometric ratio of isocyanate groups to active hydrogen groups in the "shoulder" portion is 0.2 to 0.4 less than that in the main body of the end point detection window, for example, including but not limited to 0.2, 0.3, 0.4. The isocyanate prepolymer and the polyol containing active hydrogen groups used in the main body and the "shoulder" portion of the end point detection window are the same kind, but the ratio is different.

[0045] The isocyanate compound includes one or more than two combinations of aliphatic and aromatic polyisocyanates. The isocyanate can be selected from, but not limited to, one or more than two combinations of diethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 2,6-bis(isocyanatomethyl)decahydronaphthalene, hydrogenated xylene diisocyanate, xylene diisocyanate, toluene diisocyanate, o-tolidene diisocyanate, diphenylmethane diisocyanate, m-xylylene diisocyanate, 3,9-bis(isocyanatomethyl)tricyclodecane, and the like. The polyol containing active hydrogen groups is selected from, for example, at least one of polytetramethylene ether glycol, polypropylene ether glycol, polycarbonate polyol, polycaprolactone polyol, diethyl toluene diamine, ester-based polyol of ethylene adipate or butylene adipate, and the like, for example, a copolymer or a mixture thereof, but not limited thereto.

[0046] The window body and "shoulder" are poured into the mold according to the formula. They are then placed in an oven at 60–80°C for 30–60 minutes to set and demold. The shoulder and body are then removed and placed in a molding die, which is then fixed in place with an external pressure of ≥10 MPa. The molding die is then placed in a temperature above 90°C for at least 12 hours for vulcanization. Demolding yields the final inspection window.

[0047] The obtained endpoint detection window is placed in the casting mold of the polishing layer. The polishing layer composite material is poured into the mold and cured by heating to obtain the polishing layer with the endpoint detection window. After a series of bonding processes, the final chemical mechanical polishing pad product is obtained.

[0048] The chemical mechanical polishing pad with an endpoint detection window of the present invention can be used for chemical mechanical polishing. A specific polishing method includes, for example, the following steps:

[0049] Apply pressure to the polishing element to press it onto the polishing pad;

[0050] A chemical mechanical polishing pad prepared using the aforementioned method is provided.

[0051] Provides relative motion to the polishing elements and polishing pad.

[0052] The polishing method mainly uses the chemical mechanical polishing pad of the present invention. The specific polishing equipment, polishing process and polishing liquid can be referred to the existing technology.

[0053] The present invention will be further explained and illustrated below through more specific embodiments, but these do not constitute any limitation.

[0054] The main raw materials used in the embodiments and comparative examples of this invention are as follows:

[0055] Equipment: Nanjing Chuangji SPEEDFAM 36GPAW single-sided polishing machine, four-point probe (Four Dimensions, Inc.) ) Measurement by a testing instrument.

[0056] Test method: 1. Before and after each polishing experiment, use a four-point probe (Four Dimensions, Inc.) The tester measures the thickness at 81 test points at the same location on the wafer, and calculates the removal rate based on the thickness difference. The formula for calculating the removal rate is as follows: in, This represents the average thickness of 81 test points before polishing. The average thickness of 81 test points after polishing, ΔT avgThe average value of the thickness difference before and after polishing of each of the 81 points before and after polishing was calculated. The standard deviation of the removal rate was calculated to obtain the non-uniformity ratio (%NUR). The smaller the non-uniformity ratio, i.e. the smaller the standard deviation of the removal rate, the closer the polishing rate is on the entire polishing surface, and the more uniform the polishing effect is.

[0057] 2. Shore DO hardness tester, tested according to ISO 7619:1986 GB 2411-80.

[0058] 3. The polished wafer was observed using an optical microscope. The length of the scratch was greater than 2 microns, and the total number of scratches was counted.

[0059] In the following examples and comparative examples, the polishing layer was prepared as follows:

[0060] 25.5 kg of Chemtura produced Prepolymer LF600D (NCO content 7.12%) was mixed and stirred with 0.32 kg of expanded microspheres (Akzonobel 40D42) and heated to 60°C for preheating. 5.2 kg of MOCA (Jinan Lunan Chemical) was heated to 110°C to melt and mixed and stirred with the above, poured into a mold with a terminal detection window placed in it, and gelled at room temperature. After 15 minutes of gelation, it was placed in a 100°C oven for 12 hours to obtain a polishing layer with a thickness of 2 mm. Via 3M pressure-sensitive adhesive and SUBA IV (non-woven buffer layer produced by Dow) to obtain the final chemical mechanical polishing pad.

[0061] Example 1

[0062] The preparation method of the window is as follows:

[0063] The window body was obtained by reaction of 25.8 g of Adiprene prepolymer L325 (NCO content 9.11%) and 5.5 g of diethyl toluene diamine (Shandong Jushengtai Chemical). The window body size was 50Wx70L mm, and the thickness was 2 mm. The combined liquid was mixed and stirred uniformly, then poured into a mold, and after 40 min of setting in a 60°C oven, demolded and taken out.

[0064] The "shoulder" was obtained by reaction of 10.0 g of Adiprene prepolymer L325 (NCO content 9.11%) and 2.8 g of diethyl toluene diamine (Shandong Jushengtai Chemical). The shoulder size was 35SWx35SL mm, and the thickness was 1 mm. The combined liquid was mixed and stirred uniformly, then poured into a mold, and after 40 min of setting in a 60°C oven, demolded and taken out.

[0065] The "shoulder" was placed at the center of the long side of the window body, the mold was closed, and a pressure of 10 MPa was applied outside the mold. The mold was placed in a 100 °C oven for vulcanization for 14 hours, and the end point detection window was demolded. The chemical mechanical polishing pad was obtained according to the foregoing steps.

[0066] Example 2

[0067] The window was prepared as follows:

[0068] The window body was obtained by reacting 36.7 g of Adiprene prepolymer L325 (NCO content 9.11%) with 6.4 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The window body had a size of 60Wx70L mm and a thickness of 2 mm. After the combined liquid was uniformly mixed and stirred, it was poured into a mold, and after being shaped in a 60 °C oven for 40 min, it was demolded.

[0069] The "shoulder" was obtained by reacting 8.7 g of Adiprene prepolymer L325 (NCO content 9.11%) with 1.7 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The shoulder had a size of 30SWx40SL mm and a thickness of 1.5 mm. After the combined liquid was uniformly mixed and stirred, it was poured into a mold, and after being shaped in a 60 °C oven for 40 min, it was demolded.

[0070] The "shoulder" was placed at the center of the long side of the window body and at the bottom, the mold was closed, and a pressure of 10 MPa was applied outside the mold. The mold was placed in a 100 °C oven for vulcanization for 14 hours, and the end point detection window was demolded. The chemical mechanical polishing pad was obtained according to the foregoing steps.

[0071] Example 3

[0072] The window was prepared as follows:

[0073] The window body was obtained by reacting 35.2 g of Adiprene prepolymer L325 (NCO content 9.11%) with 6.8 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The window body had a size of 55Wx80L mm and a thickness of 2 mm. After the combined liquid was uniformly mixed and stirred, it was poured into a mold, and after being shaped in a 60 °C oven for 40 min, it was demolded.

[0074] The "shoulder" was prepared by reacting 9.3 g of Adiprene prepolymer L325 (NCO content 9.11%) with 2.1 g of diethyltoluene diamine (Shandong Jinshengtai Chemical). The shoulder size was 35SW x 45SL mm, and the thickness was 0.8 mm. The combined liquid was mixed and stirred uniformly, and then poured into a mold. After being placed in a 60 °C oven for 45 min to shape, it was removed from the mold. The "shoulder" was placed at the center of the long side of the window body and at the bottom, the mold was closed, and a pressure of 10 MPa was applied outside the mold. It was placed in a 100 °C oven for vulcanization for 14 hours, and then removed from the mold to obtain the end point detection window. The chemical mechanical polishing pad was obtained according to the foregoing procedure.

[0075] Example 4

[0076] The preparation method of the window was as follows:

[0077] The window body was prepared by reacting 25.8 g of Adiprene prepolymer L325 (NCO content 9.11%) with 5.5 g of diethyltoluene diamine (Shandong Jinshengtai Chemical). The window body size was 50W x 70L mm, and the thickness was 2 mm. The combined liquid was mixed and stirred uniformly, and then poured into a mold. After being placed in a 60 °C oven for 40 min to shape, it was removed from the mold.

[0078] The "shoulder" was prepared by reacting 18.1 g of Adiprene prepolymer L325 (NCO content 9.11%) with 3.85 g of diethyltoluene diamine (Shandong Jinshengtai Chemical). The shoulder size was 35SW x 35SL mm, and the thickness was 1 mm. The combined liquid was mixed and stirred uniformly, and then poured into a mold. After being placed in a 60 °C oven for 40 min to shape, it was removed from the mold.

[0079] The "shoulder" was placed at the center of the long side of the window body, the mold was closed, and a pressure of 10 MPa was applied outside the mold. It was placed in a 100 °C oven for vulcanization for 14 hours, and then removed from the mold to obtain the end point detection window. The chemical mechanical polishing pad was obtained according to the foregoing procedure.

[0080] Comparative Example 1

[0081] The preparation method of the window without a "shoulder" was as follows:

[0082] The window body was prepared by reacting 25.8 g of Adiprene prepolymer L325 (NCO content 9.11%) with 5.5 g of diethyltoluene diamine (Shandong Jinshengtai Chemical). The window body size was 50W x 70L mm, and the thickness was 2 mm. The combined liquid was mixed and stirred uniformly, and then poured into a mold. After being placed in a 60 °C oven for 40 min to shape, it was removed from the mold.

[0083] The chemical mechanical polishing pad was obtained according to the foregoing procedure.

[0084] Comparative Example 2

[0085] The method for preparing the window without "shoulder" is as follows:

[0086] The window body is obtained by reacting 100 g of Adiprene prepolymer L325 (NCO content 9.11%) with 28 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The shoulder size is 50Wx70L mm, and the thickness is 1 mm. After the combined liquid is uniformly mixed and stirred, it is poured into a mold, and after being shaped in an oven at 60°C for 40 min, it is demolded and taken out.

[0087] The chemical mechanical polishing pad is obtained according to the foregoing procedure.

[0088] Comparative Example 3

[0089] The method for preparing the window is as follows:

[0090] The window body is obtained by reacting 25.8 g of Adiprene prepolymer L325 (NCO content 9.11%) with 5.5 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The window body size is 50Wx70L mm, and the thickness is 2 mm. After the combined liquid is uniformly mixed and stirred, it is poured into a mold, and after being shaped in an oven at 60°C for 40 min, it is demolded and taken out.

[0091] The shoulder is obtained by reacting 8.8 g of Adiprene prepolymer L325 (NCO content 9.11%) with 4.5 g of diethyltoluene diamine (Shandong Jinshengtai Chemical Industry). The shoulder size is 35SWx35SL mm, and the thickness is 1 mm. After the combined liquid is uniformly mixed and stirred, it is poured into a mold, and after being shaped in an oven at 60°C for 40 min, it is demolded and taken out.

[0092] The shoulder is placed at the center of the long side of the window body, the mold is closed, and a pressure of 10 MPa is applied outside the mold. It is vulcanized in an oven at 100°C for 14 hours, demolded to obtain the end point detection window. The chemical mechanical polishing pad is obtained according to the foregoing procedure.

[0093] Table 1 is a test data table of the examples and comparative examples.

[0094] Table 1 is a test data table of the examples and comparative examples.

[0095]

[0096] As can be seen from the table, Comparative Examples 1 and 2 are detection windows without "shoulder" prepared using the same formulations as the window body and shoulder in Example 1. Since the end point detection window is directly connected with the polishing pad, during the polishing process, due to the different frequencies of slight vibration, the non-uniformity rate of the polished original piece is high. Among them, the hardness of the window in Comparative Example 2 is smaller, so the number of scratches is relatively small. Since the hardness change rate of the window in Comparative Example 3 is greater than 20%, both the non-uniformity rate and the number of scratches are in a poor state.

[0097] While the present application has been described in detail with reference to the preferred embodiments thereof, it should be understood that the description is by way of example and that the scope of the present application is not limited to the described embodiments. Modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended to include all such modifications and alterations insofar as they come within the scope of the present application. Included in the scope of the present application are the following embodiments:

Claims

1. A chemical mechanical polishing pad with an endpoint detection window comprising a polishing layer, a buffer layer, an adhesive layer, and at least one endpoint detection window, wherein, The two long sides of the end-point detection window each have at least one "shoulder" extending into and embedded in the polishing layer connected to the detection window, and the window hardness variation rate is 2-20%, wherein the window hardness variation rate=(window hardness-"shoulder" hardness) / window hardness.

2. The chemical mechanical polishing pad of claim 1, wherein The top view shape of the end-point detection window in the polishing pad is an axisymmetric figure having long sides and short sides.

3. The chemical mechanical polishing pad of claim 2, wherein, The top view shape of the end-point detection window in the polishing pad is a rectangle.

4. The chemical mechanical polishing pad of claim 2, wherein The long sides of the end-point detection window are parallel to the diameter direction of the polishing pad, and the short sides are perpendicular to the diameter direction of the polishing pad.

5. The chemical mechanical polishing pad of claim 2 or 4, wherein, The "shoulder" of the end-point detection window is located on the long side of the detection window.

6. The chemical mechanical polishing pad of claim 5, wherein, The "shoulder" of the end-point detection window is located at the center of the long side.

7. The chemical mechanical polishing pad of claim 5, wherein The top view of the "shoulder" of the end-point detection window is any one of a rectangle, a square, a semicircle, a trapezoid, or a zigzag shape.

8. The chemical mechanical polishing pad of claim 7, wherein, The width direction of the "shoulder" is parallel to the long side direction of the detection window, and the length direction of the "shoulder" is perpendicular to the long side direction of the detection window.

9. The chemical mechanical polishing pad of claim 8, wherein, 0 10. The chemical mechanical polishing pad of claim 1, wherein The thickness of the end-point detection window is the same as the thickness of the polishing layer, and the thickness of the "shoulder" of the window is ≤2 / 3 of the thickness of the window.

11. The chemical mechanical polishing pad of claim 10, wherein The "shoulder" of the window is located below the surface of the polishing layer.

12. The chemical mechanical polishing pad of claim 11, wherein, The "shoulder" of the window is located in the middle or lower part of the polishing layer.

13. The chemical mechanical polishing pad of claim 1, wherein The surface of the polishing pad has grooves, wherein the circumferential grooves are truncated by the window at the location of the end-point detection window, and the grooves stop at the end position of the length direction of the "shoulder" of the window.

14. The chemical mechanical polishing pad of claim 1, wherein The polishing layer is a polyurethane elastomer.

15. The chemical mechanical polishing pad of claim 14, wherein The buffer layer is a polyurethane impregnated non-woven fabric material.

16. The chemical mechanical polishing pad of claim 14, wherein The adhesive layer is selected from pressure-sensitive adhesives and / or reactive hot melt adhesives.

17. A method of making a chemical mechanical polishing pad with an endpoint detection window according to any one of claims 1 to 16, characterized in that, The steps include successively curing to obtain the end-point detection window with "shoulder" and the polishing layer, and then adhering and pressing the polishing layer to the buffer layer via the adhesive layer.

18. The method of claim 17, wherein, The end-point detection window with "shoulder" is obtained by reacting a prepolymer containing isocyanate groups with a material containing unreacted active hydrogen groups.

19. The method of claim 18, wherein, The stoichiometric ratio of isocyanate groups to active hydrogen is 0.8-1.2, wherein the stoichiometric ratio of isocyanate groups to active hydrogen at the "shoulder" is 0.2-0.4 less than that in the main part of the detection window.

20. The method of claim 17, wherein, The main part and the "shoulder" are separately cast in molds according to the proportions, and then placed in an oven at 70-100°C for 30-60 min for shaping and demolding, and then the "shoulder" and the main part are taken out, and then the two are fixed in a curing mold at a pressure of not less than 10 MPa for at least 12 hours, and then demolded to obtain the end-point detection window with "shoulder".

21. Use of a chemical mechanical polishing pad with an end-point detection window as claimed in any one of claims 1-16 or prepared by the method as claimed in any one of claims 17-20 in chemical mechanical polishing.

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