Chemical mechanical rough polishing composition suitable for polishing indium phosphide substrate

Abstract

The invention relates to a chemical mechanical rough polishing composition suitable for indium phosphide substrate polishing, the rough polishing composition comprises an alumina abrasive, an oxidizing agent, a surface protective agent, a PH stabilizer and deionized water, the PH of the alumina abrasive is neutral, the average particle size of the alumina abrasive is 0.1-1 micron, the oxidizing agent is sodium hypochlorite, the surface protective agent is an azole compound, and the PH stabilizer is deionized water. The grinding wheel comprises the following components in percentage by weight: 10-50wt% of aluminum oxide grinding material; 0.1 to 1 wt% of a pH stabilizer; 1-10 wt% of an oxidizing agent; 0.01 to 0.1 wt% of a surface protective agent; the invention aims to provide the chemical mechanical rough polishing composition suitable for polishing the indium phosphide substrate, so as to solve the technical bottlenecks of poor surface quality and low polishing rate of the indium phosphide after polishing in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical mechanical polishing of ultra-precision machining and relates to a chemical mechanical rough polishing composition suitable for polishing an indium phosphide substrate. Background Art

[0002] Indium phosphide (InP) is an important III-V compound semiconductor material. It has a direct-transition band structure and a wide bandgap, resulting in a high conversion rate when used in solar cells. InP crystals have advantages such as a high electric field drift velocity, good thermal conductivity, and strong radiation resistance, making them suitable for manufacturing high-frequency, high-speed, and low-power microwave devices and circuits. In the field of optical fiber communications, InP is also a preferred communication material. During sawing and grinding processes, the wafer surface is prone to surface damage, requiring both rough polishing and fine polishing through chemical mechanical polishing (CMP) to improve surface quality. During the rough polishing process, the polishing fluid is required to achieve a high polishing rate, a non-corrosive surface, a bright surface, no significant damage, and easy cleaning after polishing. Patent CN116333601A uses a silica sol system of rough polishing solution 1 and fine polishing solution 2 for polishing InP, but does not mention the surface corrosion caused by rough polishing. Furthermore, the use of a fine polishing solution in conjunction with the polishing fluid ensures a good polishing effect. Patent CN114559302A uses a polishing fluid consisting of a base fluid and diamond powder mixed in the base fluid with a particle size of 0.01μm to 10μm. The high hardness of the diamond powder can cause significant surface damage to the indium phosphide surface, and the polishing rate is not mentioned. Domestic research on alumina abrasives is relatively rare, with most studies focusing on optimizing the polishing process and polishing equipment conditions (patents CN112975592A, CN214723256U, and CN115820128A). To meet the needs of indium phosphide electronic devices, it is urgent to develop an alumina polishing fluid that is non-corrosive, has a high polishing rate, and produces a bright surface. Summary of the Invention

[0003] The object of the present invention is to provide a chemical mechanical rough polishing composition suitable for polishing indium phosphide substrates, so as to solve the technical bottlenecks of poor surface quality and low polishing rate faced by indium phosphide in the prior art.

[0004] To achieve the above-mentioned object, the technical solution adopted by the present invention is: a chemical mechanical rough polishing composition suitable for polishing indium phosphide substrates (a polishing liquid for indium phosphide), characterized in that: the polishing liquid contains aluminum oxide abrasive, an oxidant, a surface protective agent, a pH stabilizer and deionized water, the aluminum oxide abrasive has a neutral pH and an average particle size of 0.1-1 μm, the oxidant is sodium hypochlorite, and the surface protective agent is an azole compound, and the weight percentage of each component is as follows: aluminum oxide abrasive 10-50wt%; pH stabilizer 0.1-1wt%; oxidant 1-10wt%; surface protective agent 0.01-0.1wt%; deionized water as the balance.

[0005] Furthermore, the azole compound is one of benzotriazole, methylbenzotriazole, 1,2,4-triazole, 1-methyl-1,2,4-triazole, 5-aminotetrazolyl, imidazole, methylimidazole, and mercaptobenzothiazole.

[0006] Furthermore, the pH stabilizer is one of sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, trisodium phosphate, disodium hydrogen phosphate, etc.

[0007] Compared with the prior art, the present invention has the following advantages:

[0008] This invention addresses the technical bottlenecks of poor post-polishing surface quality and low polishing rate faced by existing indium phosphide (IP) processes. The invention develops a CMP polishing liquid for rough polishing of indium phosphide. The composition and preparation process of the present invention are simple, resulting in a bright, corrosion-free, and easily cleanable wafer surface after polishing.

[0009] The beneficial effects of the present invention are as follows: 1. The surface is bright, with little damage and no surface corrosion; 2. The polishing liquid has good stability and can be stably stored for one year; 3. The ingredients are simple, the preparation is convenient, and it is environmentally friendly and pollution-free. DETAILED DESCRIPTION

[0010] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0011] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship and movement status of the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0012] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0013] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0014] The prepared polishing liquid was used for indium phosphide polishing, and the polishing conditions were as follows:

[0015] Polishing machine: Shenyang Kejing 1200S single-side polishing machine;

[0016] Wafer being polished: 2-inch indium phosphide wafer;

[0017] Polishing pad: black damping pad;

[0018] Polishing pressure: 100 g / cm2;

[0019] Workpiece speed: 40 rpm;

[0020] Lower plate speed: 50 rpm;

[0021] Polishing liquid flow rate: 10 ml / min

[0022] Polishing time: 5 minutes

[0023] After polishing, the indium phosphide surface was washed and dried, and then the surface quality of the indium phosphide sheet was measured. The surface state was determined using an electron microscope (OM).

[0024] The detailed proportions of the components of the polishing liquids of Examples 1 to 6 are shown in Table 1, and the surface states of indium phosphide after polishing with the polishing liquids are shown in Table 2.

[0025]

[0026] Table 1. Detailed ratio of each component in polishing liquid example

[0027] The surface conditions of indium phosphide after polishing with the polishing solutions of Examples 1 to 6 are shown in Table 2.

[0028] Table 2. Polishing effect of polishing liquid examples

[0029] Surface state Comparative Example 1 Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Corrosion phenomenon none Extensive corrosion none none Minor corrosion Extensive corrosion none none Removal rate (um / min) 0.36 0.5 0.75 0.78 0.45 0.63 0.80 0.57

[0030] From the polishing effects in Table 2, it can be seen that compared with the comparative example, the indium phosphide in the alumina polishing liquid of Examples 1 to 6 has good surface quality, bright surface, high removal rate, and no surface defects such as corrosion.

[0031] The polishing liquid of the present invention is used to polish the surface of indium phosphide, and has the characteristics of stable polishing performance, high polishing rate, smooth surface, and no defects such as corrosion, and can be used to manufacture high-frequency, high-speed and low-power microwave devices and circuits.

[0032] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A chemical mechanical rough polishing composition suitable for polishing indium phosphide substrates, characterized in that: The rough polishing composition comprises aluminum oxide abrasive, an oxidizing agent, a surface protecting agent, a pH stabilizer and deionized water. The aluminum oxide abrasive has a neutral pH and an average particle size of 0.1-1 μm. The oxidizing agent is sodium hypochlorite and the surface protecting agent is an azole compound. The weight percentage of each component is as follows: 10-50 wt% of the aluminum oxide abrasive; PH stabilizer 0.1-1wt%; oxidant 1-10wt%; surface protective agent 0.01-0.1wt%; deionized water as the balance.

2. A chemical mechanical rough polishing composition suitable for polishing indium phosphide substrates according to claim 1, characterized in that: The azole compound is one of benzotriazole, methylbenzotriazole, 1,2,4-triazole, 1-methyl-1,2,4-triazole, 5-aminotetrazolyl, imidazole, methylimidazole, and mercaptobenzothiazole.

3. The chemical mechanical rough polishing composition suitable for polishing indium phosphide substrates according to claim 1, characterized in that: The pH stabilizer is one of sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, trisodium phosphate, disodium hydrogen phosphate, etc.

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