A photoelectric combined CMP polishing pad and its manufacturing method

Abstract

The present invention provides a photoelectrically coupled CMP polishing pad, comprising: a base pad having a plurality of first and second accommodating areas arranged in a cross pattern. The first and second accommodating areas divide one end surface of the base pad into a plurality of polishing sections arranged in a checkerboard pattern. The first accommodating areas are used to accommodate light strips, and the second accommodating areas are used to accommodate or expose metal parts, with no interference between the metal parts and the light strips. The present invention utilizes the photoelectric field effect to improve polishing efficiency. Furthermore, through a rational checkerboard-like structure, the exposed area of ​​the metal parts and the polishing area are allocated, preventing the deposition of silicon dioxide, ensuring the removal of SiC, and improving polishing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical mechanical polishing, in particular to a photoelectrically combined CMP polishing pad. Background Art

[0002] Chemical Mechanical Polishing, or CMP, is the most widely used method for planarizing silicon wafers today. It is used multiple times in the manufacturing process and the first half of the single-crystal silicon wafer manufacturing process. Compared with the previously commonly used mechanical polishing, CMP can make the silicon wafer surface flatter and has the advantages of low processing cost and simple processing methods. Therefore, it has become the most common technology for semiconductor material surface flattening.

[0003] In the CMP process, grinding and polishing of silicon wafers are achieved through grinding pads. Therefore, the quality of the grinding pads plays a key role in the flatness of the silicon wafers. The current grinding pad materials have limited wear resistance and excessive consumption, resulting in high grinding costs and poor polishing efficiency, which is difficult to meet market demand. Summary of the Invention

[0004] The present invention aims to solve the blanks in the prior art and provides a photoelectrically combined CMP polishing pad and a corresponding manufacturing method.

[0005] The present invention solves the technical problem by adopting the following technical solution: a photoelectric combined CMP polishing pad, comprising:

[0006] A base pad is provided with multiple first accommodating areas and second accommodating areas distributed in a cross shape, the first accommodating areas and the second accommodating areas divide one end surface of the base pad into multiple grinding parts distributed in a checkerboard shape, the first accommodating areas are used to set the light strip, and the second accommodating areas are used to set or expose metal parts, and there is no interference between the metal parts and the light strip.

[0007] In several embodiments, the base pad is foamed from the following components in percentage by mass: 10%-30% cerium oxide powder, 60%-85% polyurethane, and 5%-10% auxiliary agent.

[0008] In several embodiments, the auxiliary agent includes diisocyanate, an anti-hydrolysis agent, a chain extender, a hollow filler, and a plasticizer.

[0009] In several embodiments, the first accommodating area and the second accommodating area are both grooves recessed on one end surface of the base pad, there is a gap between adjacent first accommodating areas and second accommodating areas, the first accommodating areas located on the same straight line are continuously arranged, and multiple second accommodating areas located on the same straight line are spaced apart.

[0010] In several embodiments, the first accommodating area is a groove recessed on one end face of the base pad, the second accommodating area is a hole penetrating the base pad, a plurality of the second accommodating areas located on the same straight line are spaced apart, and both ends of the second accommodating area extend to the first accommodating areas on the adjacent two sides.

[0011] In several embodiments, the optoelectronic CMP polishing pad is formed using the following manufacturing method:

[0012] S100: After selecting a certain amount of polyurethane and stirring it, foaming it to form a mixed sol, adding a certain amount of cerium oxide powder and an auxiliary agent to the mixed sol, mixing them evenly, and then passing them into a mold for molding and cooling to obtain a base pad;

[0013] S200: Cutting the base mat along the cross lines to form concave grooves, wherein the longitudinal grooves are cut continuously, and the transverse grooves are cut at intervals in a dotted pattern, thereby forming the first accommodating area and the second accommodating area;

[0014] S300: laying a light strip in the first accommodating area, and laying a metal piece in the second accommodating area, to obtain a photoelectrically combined CMP polishing pad.

[0015] In several embodiments, the optoelectronic CMP polishing pad is formed using the following manufacturing method:

[0016] S100: After selecting a certain amount of polyurethane and stirring it, foaming it to form a mixed sol, adding a certain amount of cerium oxide powder and an auxiliary agent to the mixed sol, mixing them evenly, and then passing them into a mold for molding and cooling to obtain a base pad;

[0017] S200: cutting the base mat along a cross pattern to form concave grooves, wherein the grooves are staggered and the transversely distributed grooves are subjected to through-hole drilling, thereby forming a first accommodating area and a second accommodating area;

[0018] S300: Laying a light strip in a first accommodating area formed on the front side of the base pad, and fixing a metal piece on the back side of the base pad so that the metal piece completely covers the back side of the base pad, thereby obtaining a photoelectrically combined CMP polishing pad.

[0019] The present invention has the following beneficial effects:

[0020] The present invention uses physical foaming to create a uniform polishing pad with excellent wear and corrosion resistance, ensuring efficient flattening of protruding portions of the wafer surface profile and minimizing scratches. Furthermore, cerium oxide improves the polishing pad's wear resistance, making it more uniform and compact, making it more suitable for SiC grinding and polishing.

[0021] The present invention utilizes the photoelectric field effect to improve the grinding efficiency, and distributes the exposed area and the grinding area of ​​the metal part through a reasonable chessboard structure, thereby avoiding the deposition of silicon dioxide, ensuring the removal of SiC, and improving the polishing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are for illustrative purposes only of selected embodiments and do not represent all possible implementations, and should not be considered to limit the scope of the present invention.

[0023] Figure 1 A schematic diagram of a photoelectrically combined CMP polishing pad according to an embodiment is shown;

[0024] Figure 2 The structure of a low-loss grinding unit and a low-loss polishing unit in one embodiment is schematically shown;

[0025] Figure 3 Schematically shows Figure 2 Top view of the low- and medium-loss polishing unit. DETAILED DESCRIPTION

[0026] Below, the embodiments of the present invention are described in detail. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative work are within the scope of protection of the present invention.

[0028] The terms used herein are intended to explain the embodiments and are not intended to limit and / or define the present invention.

[0029] The grinding pad provided by the present invention is used in a CMP process and is mainly used to cooperate with a grinding head to grind and polish the surface of a silicon wafer.

[0030] The optoelectronic combined CMP polishing pad has a main body of a base pad 10 with a disc-shaped structure, which is adapted to the shape of a silicon wafer. A plurality of first accommodating areas 11 and second accommodating areas 12 distributed in a cross shape are provided on the base pad 10. The first accommodating areas 11 and the second accommodating areas 12 divide one end face of the base pad 10 into a plurality of polishing parts 13 distributed in a checkerboard shape. The polishing parts 13 are in contact with the silicon wafer for polishing. The first accommodating area 11 is used to set the light bar 20, and the second accommodating area 12 is used to set or expose the metal part 30. There is no interference between the metal part 30 and the light bar 20.

[0031] The light strip 20 is used as a light source, such as an LED light strip with lamp beads, and the metal part 30 is made of nickel sheet material and connected to a power supply. The principle of photoelectric combination is: after the silicon carbide in the silicon wafer absorbs visible light, it transfers the energy of the outer electrons, that is, the electrons jump to a higher energy state, thereby increasing the reaction treatment with the chemical agent. At the same time, the addition of electrical energy can also promote the electrons to jump to a high energy state, further providing reaction treatment, thereby accelerating the polishing efficiency.

[0032] The base pad 10 is foamed and formed by the following components in percentage by mass: 10%-30% cerium oxide powder, 60-85% polyurethane, and 5%-10% auxiliary agent. The auxiliary agent is composed of equal amounts of diisocyanate, anti-hydrolysis agent, chain extender, hollow filler and plasticizer.

[0033] Example 1

[0034] The base pad 10 is foamed from the following components in percentage by mass: 10% cerium oxide powder, 85% polyurethane, and 5% auxiliary agent, wherein the auxiliary agent is composed of equal amounts of diisocyanate, anti-hydrolysis agent, chain extender, hollow filler, and plasticizer.

[0035] Example 2

[0036] The base pad 10 is foamed from the following components in percentage by mass: 20% cerium oxide powder, 72% polyurethane, and 8% auxiliary agent, wherein the auxiliary agent is composed of equal amounts of diisocyanate, anti-hydrolysis agent, chain extender, hollow filler, and plasticizer.

[0037] Example 3

[0038] The base pad 10 is foamed from the following components in percentage by mass: 30% cerium oxide powder, 60% polyurethane, and 10% auxiliary agent, wherein the auxiliary agent is composed of equal amounts of diisocyanate, anti-hydrolysis agent, chain extender, hollow filler, and plasticizer.

[0039] Example 4

[0040] Here, the first accommodating area 11 and the second accommodating area 12 are both grooves provided concavely on one end surface of the base pad 10. There is a gap between adjacent first accommodating areas 11 and second accommodating areas 12. The first accommodating areas 11 located on the same straight line are continuously provided, and the plurality of second accommodating areas 12 located on the same straight line are spaced apart. The optoelectronic combined CMP polishing pad is formed by the following manufacturing method:

[0041] S100: After selecting a certain amount of polyurethane and stirring it, foaming it to form a mixed sol, adding a certain amount of cerium oxide powder and an auxiliary agent to the mixed sol, mixing them evenly, and then passing them into a mold for molding and cooling to obtain a base pad 10;

[0042] S200: The base pad 10 is cut along a cross pattern using a CNC machine to form concave grooves, wherein the longitudinal grooves are cut continuously, while the transverse grooves are cut at intervals in a dotted pattern, thereby forming the first accommodating area 11 and the second accommodating area 12;

[0043] S300: laying the light strip 20 in the first accommodating area 11 and laying the metal member 30 in the second accommodating area 12 to obtain a photoelectrically combined CMP polishing pad.

[0044] That is, in the fourth embodiment, the second accommodating area 12 is cut and formed in a dot-break manner, thereby avoiding intersection with the first accommodating area 11 .

[0045] Example 5

[0046] Here, the first accommodating area 11 is a groove concavely arranged on one end face of the base pad 10, and the second accommodating area 12 is a hole body penetrating the base pad 10. Multiple second accommodating areas 12 located on the same straight line are arranged at intervals, and both ends of the second accommodating area 12 extend to the first accommodating areas 11 on the adjacent two sides.

[0047] The optoelectronic CMP polishing pad is formed by the following manufacturing method:

[0048] S100: After selecting a certain amount of polyurethane and stirring it, foaming it to form a mixed sol, adding a certain amount of cerium oxide powder and an auxiliary agent to the mixed sol, mixing them evenly, and then passing them into a mold for molding and cooling to obtain a base pad 10;

[0049] S200: The base pad 10 is cut along a cross pattern using a CNC machine to form concave grooves. The grooves are staggered and the transverse grooves are penetrated and opened, thereby forming the first accommodating area 11 and the second accommodating area 12.

[0050] S300: Lay the light strip 20 in the first accommodating area 11 formed on the front side of the base pad 10, and fix the metal part 30 on the back side of the base pad 10. The metal part 30 completely covers the back side of the base pad 10, thereby obtaining a photoelectric combined CMP polishing pad.

[0051] Here, if the diameter of the polishing pad is 70 cm, the length of a single second accommodating area 12 is about 2 cm and the width is about 0.3 cm. The single second accommodating area 12 is a narrow strip-shaped opening between two adjacent first accommodating areas 11 and two adjacent polishing parts 13.

[0052] That is, in Example 5, the first accommodating area 11 and the second accommodating area 12 are directly cross-cut to form, and then the non-crossing part of the second accommodating area 12 is further cut downward to penetrate the base pad 10 to form an opening, through which the metal part 30 can be exposed, and then an electrical reaction is realized.

[0053] It should be noted that in Examples 4 and 5, the exposed area of ​​the metal part 30 is approximately 1 / 10-1 / 4 of the area of ​​an end surface of the base pad 10. Excessive exposed area of ​​the metal part 30 will lead to too fast reaction efficiency, resulting in the deposition of silicon dioxide produced by the reaction, and there will be no time to remove the silicon dioxide. By reasonably designing the exposed area of ​​the metal part 30, the normal reaction and removal of silicon carbide can be guaranteed, and the balance between reaction and removal can be maintained.

[0054] It should be noted that in Example 4, continuous and uninterrupted cutting and forming can also be performed directly on the same straight line as in Example 5, except that the metal parts 30 are laid in a discontinuous manner in the second accommodating area 12, and the metal parts 30 must be kept from contacting the light strip.

[0055] Furthermore, in the fifth embodiment, the metal member 30 can be directly placed in the foaming mold and integrally formed with the base pad 10 , and then the first accommodating area 11 and the second accommodating area 12 are cut and formed.

[0056] Therefore, the structure of the polishing pad can facilitate the forming of the groove body and can also facilitate the control of the exposed amount of the metal part 30 according to needs.

[0057] The illustrated examples, embodiments, and particular forms of the present invention have been shown and described in detail in the accompanying drawings and the foregoing description and should likewise be considered illustrative rather than restrictive. The description of particular features in one embodiment does not necessarily mean that those particular features are limited to that embodiment. Features of one embodiment may be used in combination with features of other embodiments, as will be understood by those skilled in the art, whether or not explicitly stated otherwise. Exemplary embodiments have been shown and described, and all variations and improvements fall within the spirit of the present invention and are intended to be protected.

Claims

1. A photoelectric CMP polishing pad, characterized in that: include: A base pad having a plurality of first and second accommodating areas arranged in a cross shape, wherein the first and second accommodating areas divide an end surface of the base pad into a plurality of polished portions arranged in a checkerboard pattern, wherein the first accommodating areas are used to accommodate light strips, and the second accommodating areas are used to expose metal parts, and the metal parts do not interfere with the light strips; The photoelectric combined CMP polishing pad is formed by the following manufacturing method: S100: After selecting a certain amount of polyurethane and stirring it, foaming it to form a mixed sol, adding a certain amount of cerium oxide powder and an auxiliary agent to the mixed sol, mixing them evenly, and then passing them into a mold for molding and cooling to obtain a base pad; S200: cutting the base mat along a cross pattern to form concave grooves, wherein the grooves are staggered and the transversely distributed grooves are subjected to through-hole drilling, thereby forming a first accommodating area and a second accommodating area; S300: Laying a light strip in a first accommodating area formed on the front side of the base pad, and fixing a metal piece on the back side of the base pad so that the metal piece completely covers the back side of the base pad, thereby obtaining a photoelectrically combined CMP polishing pad.

2. The photoelectric CMP polishing pad according to claim 1, wherein: The base pad is foamed and formed by the following components in percentage by mass: 10%-30% cerium oxide powder, 60-85% polyurethane, 5%-10% additives.

3. The photoelectric CMP polishing pad according to claim 2, wherein: The auxiliary agents include diisocyanate, anti-hydrolysis agent, chain extender, hollow filler and plasticizer.

4. The photoelectric CMP polishing pad according to claim 3, wherein: The first accommodating area and the second accommodating area are both grooves concavely arranged on one end surface of the base pad. There is a gap between adjacent first accommodating areas and second accommodating areas. The first accommodating areas located on the same straight line are arranged continuously, and multiple second accommodating areas located on the same straight line are arranged at intervals.

5. The photoelectric CMP polishing pad according to claim 3, wherein: The first accommodating area is a groove concavely arranged on one end surface of the base pad, and the second accommodating area is a hole body penetrating the base pad. Multiple second accommodating areas located on the same straight line are arranged at intervals, and both ends of the second accommodating area extend to the first accommodating areas on both adjacent sides.

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