Silicon wafer rough polishing pad with water injection holes and manufacturing process thereof

Abstract

The application discloses a silicon wafer rough polishing pad with water injection holes on the surface and a manufacturing process, and belongs to the technical field of polishing pads. The silicon wafer rough polishing pad comprises a base layer and a polishing layer, the surface of the base layer is bonded with the polishing layer, and the polishing layer is provided with uniformly distributed water injection holes. The water injection holes are used for discharging the coolant to cool the surface of the polishing layer when the silicon wafer is rough polished. The application solves the problem that the surface of the existing polishing pad cannot uniformly supply the coolant when the silicon wafer is rough polished, the polishing pad cannot be effectively cooled and the polishing efficiency of the polishing pad is low, and the surface quality of the rough polished silicon wafer is poor. When the polishing pad is used to rough polish the silicon wafer, the polishing pad and the silicon wafer are extruded with each other, the coolant absorbed and stored in the water storage elastomer in the water injection hole is extruded and discharged, the surface of the polishing layer is uniformly supplied with the coolant, the polishing pad can be effectively cooled and the polishing efficiency of the polishing pad is improved during the rough polishing of the silicon wafer, and the surface quality of the rough polished silicon wafer is improved.

Description

Technical Field

[0001] This invention relates to the field of white pad technology, specifically to a rough polishing white pad for silicon wafers with water injection holes on the surface and its manufacturing process. Background Technology

[0002] Rough polishing of silicon wafers is an important step in the chemical mechanical polishing process. Its purpose is to remove the damaged layer on the surface of the silicon wafer through chemical and mechanical action, while improving surface smoothness and roughness.

[0003] Existing white pads cannot achieve uniform coolant supply on their surface during the rough polishing of silicon wafers, and cannot effectively cool the white pads during the rough polishing process, resulting in low polishing efficiency and poor surface quality of the silicon wafers. Summary of the Invention

[0004] The purpose of this invention is to provide a white pad for rough polishing silicon wafers with water injection holes on its surface and a manufacturing process thereof. When the white pad is used for rough polishing of the silicon wafer, the white pad and the silicon wafer are squeezed together, causing the coolant absorbed and stored on the water-retaining elastomer in the water injection holes to be squeezed out. This provides a uniform supply of coolant to the surface of the polished layer, effectively cooling the white pad during the rough polishing process, improving the polishing efficiency of the white pad, and enhancing the surface quality of the rough polished silicon wafer, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A silicon wafer rough polishing pad with water injection holes on its surface includes a base layer and a polishing layer. The polishing layer is bonded to the surface of the base layer. The polishing layer has uniformly distributed water injection holes, which are used to discharge coolant during the rough polishing of the silicon wafer to cool the surface of the polishing layer.

[0007] Preferably, the base layer comprises the following raw materials in parts by weight: 25-40 parts toluene diisocyanate, 55-65 parts polyether polyol, 0.1-1 parts amine catalyst, 0.1-1 parts foaming agent, 1-2 parts surfactant, 1-2 parts flame retardant and 1-2 parts stabilizer.

[0008] Preferably, the polishing layer includes a polishing underlayer and a polishing surface layer, wherein the polishing underlayer is bonded to the base layer, and the polishing surface layer is bonded to the surface of the polishing underlayer.

[0009] Preferably, a water storage cavity is provided on the inner side of the polishing substrate, the water storage cavity is connected to a water injection hole, and the water injection hole is provided on the polishing surface layer.

[0010] Preferably, a water-storing elastomer is provided inside the water injection hole, and the water-storing elastomer penetrates the polished surface layer.

[0011] Preferably, the water-retaining elastomer is made of polyurethane foam plastic, which is extruded by an extruder and then processed to form a ring-shaped water-retaining elastomer.

[0012] Preferably, the water injection holes on the surface of the polished layer are distributed in a circular pattern, and the number of circular water injection holes is 1, 3, or 5.

[0013] Preferably, the polished surface layer comprises the following raw materials in parts by weight: 50-70 parts submicron cerium oxide, 2-5 parts zirconium oxide, 5-10 parts chromium oxide, 10-15 parts rare earth elements, 5-10 parts silicon dioxide, and the balance cobalt.

[0014] According to another aspect of the present invention, a process for fabricating a silicon wafer rough polishing pad with water injection holes on its surface is provided, for fabricating a silicon wafer rough polishing pad with water injection holes as described above, comprising:

[0015] Toluene diisocyanate, polyether polyol, amine catalyst, foaming agent, surfactant, flame retardant and stabilizer are added to the reaction vessel, and the raw materials in the reaction vessel are stirred to make them evenly mixed, and the base layer is formed after processing.

[0016] A water storage cavity is opened on the surface of the polished bottom layer, and water injection holes are evenly distributed on the polished surface layer. A ring-shaped water storage elastomer, which is made of polyurethane foam plastic and is formed by extrusion and processing, is processed into the water injection holes.

[0017] The polished surface layer is bonded to the polished base layer, and the polished base layer is bonded to the base layer. The base layer, polished base layer and polished surface layer are laminated to form a white pad.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention injects coolant through a water injection hole, and the coolant enters the water storage chamber. When the white pad is used for rough polishing of the silicon wafer, the white pad and the silicon wafer are squeezed together, causing the coolant absorbed and stored on the water storage elastomer in the water injection hole to be squeezed out and uniformly supplying coolant to the surface of the polished layer. This can effectively cool and reduce the temperature of the white pad during the rough polishing process of the silicon wafer, improve the polishing efficiency of the white pad, and improve the surface quality of the rough polished silicon wafer. Attached Figure Description

[0020] Figure 1 This is a structural diagram of a silicon wafer rough polishing pad with water injection holes on its surface, according to Embodiment 1 of the present invention.

[0021] Figure 2 This is a cross-sectional view of a silicon wafer rough polished with a water injection hole on its surface, according to Embodiment 1 of the present invention.

[0022] Figure 3 For the present invention Figure 2Enlarged view of point A in the image;

[0023] Figure 4 This is a structural diagram of a silicon wafer rough polishing pad with water injection holes on its surface, as shown in Embodiment 2 of the present invention.

[0024] Figure 5 This is a structural diagram of a silicon wafer rough polishing pad with water injection holes on its surface, as shown in Embodiment 3 of the present invention.

[0025] Figure 6 This is a top view of a silicon wafer rough polished with water injection holes on its surface, according to Embodiment 3 of the present invention.

[0026] In the diagram: 1. Base layer; 2. Polished layer; 21. Polished bottom layer; 22. Polished top layer; 3. Water injection hole; 4. Water storage cavity; 5. Water storage elastomer. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To address the problem that existing white pads cannot achieve uniform coolant supply during the rough polishing of silicon wafers, thus failing to effectively cool the white pads and resulting in low polishing efficiency and poor surface quality, please refer to [link to relevant documentation]. Figures 1-6 This embodiment provides the following technical solution:

[0029] Example 1

[0030] A silicon wafer with water injection holes is coarsely polished and whitened, including a base layer 1 and a polishing layer 2, with the polishing layer 2 bonded to the surface of the base layer 1.

[0031] In this embodiment, the substrate layer 1 comprises the following raw materials in parts by weight: 25-40 parts of toluene diisocyanate, 55-65 parts of polyether polyol, 0.1-1 parts of amine catalyst, 0.1-1 parts of foaming agent, 1-2 parts of surfactant, 1-2 parts of flame retardant and 1-2 parts of stabilizer.

[0032] The polished layer 2 is provided with uniformly distributed water injection holes 3. The water injection holes 3 are used to squeeze out coolant during the rough polishing of silicon wafers to cool the surface of the polished layer 2.

[0033] In this embodiment, the polishing layer 2 includes a polishing underlayer 21 and a polishing surface layer 22. The polishing underlayer 21 is bonded to the base layer 1, and the polishing surface layer 22 is bonded to the surface of the polishing underlayer 21. A water storage cavity 4 is provided on the inner side of the polishing underlayer 21. The water storage cavity 4 is connected to a water injection hole 3, and the water injection hole 3 is provided on the polishing surface layer 22.

[0034] In this embodiment, a water-storing elastomer 5 is provided inside the water injection hole 3. The water-storing elastomer 5 penetrates the polished surface layer 22. The water-storing elastomer 5 is made of polyurethane foam plastic as raw material. After being extruded by an extruder, it is processed to form an annular water-storing elastomer 5.

[0035] It should be noted that polyurethane foam is made by polymerizing and foaming isocyanates and hydroxyl compounds. It has excellent elasticity, softness, elongation and compressive strength; good chemical stability, and resistance to many solvents and oils; excellent wear resistance; and excellent processability, heat insulation and adhesion. It is a high-performance cushioning material with excellent water absorption characteristics, which can absorb and store the coolant in the water injection hole 3, so as to better realize the coolant supply.

[0036] In this embodiment, the water injection holes 3 on the surface of the polished surface layer 22 are distributed in a circular pattern, and the number of circular water injection holes 3 is 1.

[0037] In this embodiment, the polished surface layer 22 comprises the following raw materials in parts by weight: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth elements, 5-10 parts of silicon dioxide, and the balance cobalt.

[0038] Specifically, coolant is injected through water injection hole 3 and enters water storage chamber 4. When the white pad is used for rough polishing of silicon wafer, the white pad and silicon wafer are squeezed together, causing the coolant absorbed and stored on the water storage elastomer 5 in water injection hole 3 to be squeezed out and uniformly supplied to the surface of polishing layer 2. This can effectively cool down the white pad during the rough polishing process of silicon wafer, improve the polishing efficiency of the white pad, and improve the surface quality of the rough polished silicon wafer.

[0039] To better illustrate the fabrication process of a rough polishing white pad for silicon wafers with water injection holes on the surface, this embodiment provides a fabrication process for a rough polishing white pad for silicon wafers with water injection holes on the surface, used to fabricate the aforementioned rough polishing white pad for silicon wafers with water injection holes on the surface, including:

[0040] Toluene diisocyanate, polyether polyol, amine catalyst, foaming agent, surfactant, flame retardant and stabilizer are added to the reaction vessel, and the raw materials in the reaction vessel are stirred to make them uniformly mixed. After processing, the base layer 1 is formed.

[0041] A water storage cavity 4 is opened on the surface of the polished bottom layer 21, and water injection holes 3 are evenly distributed on the polished surface layer 22. An annular water storage elastomer 5, which is made of polyurethane foam plastic and is formed by extrusion and processing, is processed in the water injection hole 3.

[0042] The polished surface layer 22 is bonded to the polished bottom layer 21, and the polished bottom layer 21 is bonded to the base layer 1. The base layer 1, the polished bottom layer 21 and the polished surface layer 22 are laminated to form a white pad.

[0043] Example 2

[0044] Compared with Example 1, the difference is that the number of circular water injection holes 3 distributed on the surface of the polished surface layer 22 is 3.

[0045] Example 3

[0046] Compared with Example 1, the difference is that the number of circular water injection holes 3 distributed on the surface of the polished surface layer 22 is 5.

[0047] Comparative Example

[0048] The silicon wafer rough polishing pad includes a base layer 1 and a polishing layer 2, with the polishing layer 2 bonded to the surface of the base layer 1.

[0049] In this embodiment, the substrate layer 1 comprises the following raw materials in parts by weight: 25-40 parts of toluene diisocyanate, 55-65 parts of polyether polyol, 0.1-1 parts of amine catalyst, 0.1-1 parts of foaming agent, 1-2 parts of surfactant, 1-2 parts of flame retardant and 1-2 parts of stabilizer.

[0050] In this embodiment, the polishing layer 2 includes a polishing underlayer 21 and a polishing surface layer 22. The polishing underlayer 21 is bonded to the base layer 1, and the polishing surface layer 22 is bonded to the surface of the polishing underlayer 21. The polishing surface layer 22 includes the following raw materials in parts by weight: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth elements, 5-10 parts of silicon dioxide, and the balance cobalt.

[0051] The performance of the coarse polished white pads for silicon wafers manufactured according to the above process was tested, and the results are shown in Table 1.

[0052] Table 1: Performance Test Results of White Pads for Rough Polishing of Silicon Wafers

[0053] Cooling rate / 100% 92.36％ 94.47％ 96.18％ 82.19％ Polishing efficiency / 100% 93.18％ 94.96％ 97.29％ 82.67％ Rough polishing surface quality / 100% 92.89％ 94.64％ 96.83％ 82.35％

[0054] Therefore, compared with Example 1, Example 2 has an increase in the number of circular water injection holes 3 distributed on the surface of the polished surface layer 22 from 1 to 3. This makes the supply of coolant in the water injection holes 3 more uniform, thereby improving the cooling rate, polishing efficiency and surface quality of the silicon wafer rough polishing pad.

[0055] Therefore, compared with Example 2, Example 3 has an increase in the number of circular water injection holes 3 distributed on the surface of the polished surface layer 22 from 3 to 5. This makes the supply of coolant in the water injection holes 3 more uniform, thereby improving the cooling rate, polishing efficiency and surface quality of the silicon wafer rough polishing pad.

[0056] Therefore, compared with Example 1, since the polished surface layer 22 does not have uniformly distributed water injection holes 3, the white pad cannot provide a uniform supply of coolant when rough polishing the silicon wafer, resulting in a decrease in the cooling rate, polishing efficiency and surface quality of the rough polished silicon wafer.

[0057] In summary, by injecting coolant through the water injection hole 3 and having the coolant enter the water storage chamber 4, the white pad and the silicon wafer are squeezed together during the rough polishing of the silicon wafer. This causes the coolant absorbed and stored on the water storage elastomer 5 in the water injection hole 3 to be squeezed out, and provides a uniform supply of coolant to the surface of the polishing layer 2. This effectively cools and reduces the temperature of the white pad during the rough polishing process of the silicon wafer, improves the polishing efficiency of the white pad, and enhances the surface quality of the rough polished silicon wafer.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A silicon wafer rough-polished white pad with water injection holes on its surface, comprising a substrate layer (1) and a polishing layer (2), characterized in that, The surface of the base layer (1) is bonded with a polishing layer (2), and the polishing layer (2) is provided with uniformly distributed water injection holes (3). The water injection holes (3) are used to squeeze out coolant during the rough polishing of the silicon wafer to cool the surface of the polishing layer (2). The polishing layer (2) includes a polishing base layer (21) and a polishing surface layer (22). The polishing base layer (21) is bonded to the base layer (1). The polishing surface layer (22) is bonded to the surface of the polishing base layer (21). A water storage cavity (4) is provided inside the polishing base layer (21). The water storage cavity (4) is connected to a water injection hole (3). The water injection hole (3) is provided on the polishing surface layer (22). A water storage elastomer (5) is provided inside the water injection hole (3). The water storage elastomer (5) penetrates the polishing surface layer (22). The water storage elastomer (5) is made of polyurethane foam plastic as raw material. After being extruded by an extruder, it is processed to form a ring-shaped water storage elastomer (5). The water injection holes (3) on the surface of the polished surface layer (22) are distributed in a circular pattern, and the number of circular water injection holes (3) is 1, 3 or 5.

2. The silicon wafer rough polishing pad with water injection holes as described in claim 1, characterized in that, The base layer (1) comprises the following raw materials in parts by weight: 25-40 parts toluene diisocyanate, 55-65 parts polyether polyol, 0.1-1 parts amine catalyst, 0.1-1 parts foaming agent, 1-2 parts surfactant, 1-2 parts flame retardant and 1-2 parts stabilizer.

3. The silicon wafer rough polishing pad with water injection holes as described in claim 2, characterized in that, The polished surface layer (22) comprises the following raw materials in parts by weight: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth, 5-10 parts of silicon dioxide, and the balance cobalt.

4. A process for manufacturing a silicon wafer rough polishing pad with water injection holes on its surface, used to manufacture a silicon wafer rough polishing pad with water injection holes as described in any one of claims 1-3, characterized in that, include: Toluene diisocyanate, polyether polyol, amine catalyst, foaming agent, surfactant, flame retardant and stabilizer are added to the reactor and the raw materials in the reactor are stirred to make them evenly mixed and formed into a base layer after processing (1). A water storage cavity (4) is opened on the surface of the polished bottom layer (21), and water injection holes (3) are evenly distributed on the polished surface layer (22). A ring-shaped water storage elastomer (5) formed by extruding and processing polyurethane foam plastic is processed in the water injection hole (3). The polished surface layer (22) is bonded to the polished bottom layer (21), and the polished bottom layer (21) is bonded to the base layer (1). The base layer (1), the polished bottom layer (21) and the polished surface layer (22) are laminated to form a white pad.

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