Glue for bonding high-temperature electrostatic chuck as well as preparation method and application of glue

Abstract

The invention relates to glue for bonding a high-temperature electrostatic chuck as well as a preparation method and application thereof, and relates to the technical field of glue. The glue is prepared from the following components in parts by weight: 28 to 40 parts of octamethylcyclotetrasiloxane, 35 to 40 parts of aluminum oxide, 2 to 4 parts of calcium carbonate, 3 to 5 parts of silicon oxide, 2 to 4 parts of polymer filler, 2 to 5 parts of silicate, 5 to 8 parts of non-oxide filler, 3 to 6 parts of organic acid ester, 2 to 5 parts of tin catalyst and 1 to 2 parts of silane coupling agent. During preparation, aluminum oxide and octamethylcyclotetrasiloxane are firstly subjected to ball milling for 8 hours, and then other raw materials are added for ball milling for 16 hours. The glue has high thermal conductivity, excellent high temperature resistance, good mechanical strength and high bonding tensile strength, and can maintain good corrosion resistance at the working temperature of 400 DEG C or above if being applied to high-temperature bonding of the electrostatic chuck.

Description

Technical Field

[0001] The present invention relates to the technical field of glue, and in particular to glue for bonding high-temperature electrostatic chucks, a preparation method and application thereof. Background Art

[0002] Ceramic electrostatic chucks are widely used in semiconductor wafer etching, optics, and other fields. The ceramic chuck and aluminum base are typically bonded with glue. With the continued development of advanced etching applications, long-term use of the ESC can cause the ceramic and adhesive layers to age, corrode, and fall off. This can lead to an increase in particulate matter within the cavity, affecting etching and causing frequent machine swings. The thermal conductivity of conventional ESC mounting glue is typically between 0.6-0.9W / MK, and the operating temperature is limited to 100°C. Furthermore, in advanced etching applications, high-energy plasma continuously erodes the exposed glue. Conventional glue typically corrodes after approximately 5,000 hours, making it unsuitable for etching equipment. Summary of the Invention

[0003] The present invention provides a glue for bonding high-temperature electrostatic chucks, which solves the problems of aging, corrosion and shedding of glue in high-process etching applications. In addition, the silicone gel has the advantages of being resistant to high temperatures, aging, and not easily corroded by plasma bombardment, while also having a very high heat conduction function.

[0004] The technical solution adopted to achieve the above-mentioned purpose of the present invention is: In a first aspect, the present invention proposes a glue for bonding a high-temperature electrostatic chuck. The raw materials of the glue are, by weight, 28-40 parts of octamethylcyclotetrasiloxane, 35-40 parts of aluminum oxide, 2-4 parts of calcium carbonate, 3-5 parts of silicon oxide, 2-4 parts of polymer filler, 2-5 parts of silicate, 5-8 parts of non-oxide filler, 3-6 parts of organic acid ester, 2-5 parts of tin catalyst, and 1-2 parts of silane coupling agent.

[0005] Preferably, the non-oxide filler is one or a combination of aluminum nitride and graphene. The aluminum nitride and graphene components can greatly improve the thermal conductivity level of the glue.

[0006] Preferably, the glue is divided into component A and component B, and both component A and component B contain octamethylcyclotetrasiloxane, aluminum oxide, calcium carbonate, silicon oxide, polymer filler, silicate, non-oxide filler, organic acid ester, tin catalyst and silane coupling agent; the non-oxide filler in component A is aluminum nitride, and the non-oxide filler in component B is graphene; the weight ratio of component A to component B is 1:1.

[0007] Preferably, the polymer filler is polyimide. Polyimide, as a high-temperature resistant polymer, significantly improves the high-temperature stability of the adhesive layer.

[0008] Preferably, the silicate is mica powder, and the addition of mica powder can enhance the mechanical strength and insulation of the glue.

[0009] Preferably, the tin catalyst is stannous octoate, which is a highly efficient tin catalyst and can control the curing rate.

[0010] Preferably, the silane coupling agent is trimethylsilane, which is used to promote the curing reaction of the glue.

[0011] Preferably, the organic acid ester is citrate, which is used to improve the flexibility of the colloid.

[0012] In a second aspect, the present invention also proposes a method for preparing glue for bonding high-temperature electrostatic suction cups, comprising the following steps: mixing powdered alumina and octamethylcyclotetrasiloxane and performing a first stage of ball milling; adding the remaining raw materials to the mixture after the first stage of ball milling, and performing a second stage of ball milling, wherein the non-oxide filler in the remaining raw materials is powdered; the first stage of ball milling time is 6-10 hours, and the second stage of ball milling time is 12-20 hours, and the viscosity of the final colloid is controlled within the range of 8000-10000 cP.

[0013] In a third aspect, the present invention further proposes an application of a high-temperature electrostatic chuck bonding glue in an electrostatic chuck, wherein the electrostatic chuck comprises a ceramic disc and an aluminum base, and the glue bonds the ceramic disc and the aluminum base to each other.

[0014] The beneficial effects of the present invention are as follows: 1) The adhesive for bonding high-temperature electrostatic chucks proposed in this invention incorporates silicon oxide, polyimide, and mica powder, significantly enhancing its high-temperature resistance and mechanical strength. During plasma etching, the adhesive maintains its properties even at temperatures exceeding 300°C and is not easily corroded by plasma bombardment, effectively extending the lifespan of the electrostatic chuck. 2) The glue for bonding the high-temperature electrostatic chuck proposed in the present invention is added with aluminum nitride and graphene powder with high thermal conductivity. The thermal conductivity of the glue reaches above 4 W / mk, which can achieve temperature uniformity during the etching process, thereby improving the yield of the etched product. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is described in detail below with reference to the examples, but the scope of protection of the present invention is not limited thereto. The raw materials involved in the examples are all commercially available specifications, and the process parameters can be adjusted according to actual production needs.

[0016] A method for preparing glue for bonding high-temperature electrostatic chucks, the specific steps are as follows: Component A and component B are separately prepared by a two-stage ball milling method. The two-stage ball milling method includes a first ball milling stage and a second ball milling stage. In the first ball milling stage, aluminum oxide powder and octamethylcyclotetrasiloxane are first mixed and ball milled for 8 hours; in the second ball milling stage, calcium carbonate, silicon oxide, polyimide, mica powder, non-oxidizing filler, citrate, stannous octoate and trimethylsilane are added to the mixture after the first ball milling, and ball milled for 16 hours. The non-oxidizing filler in component A is aluminum nitride powder, and in component B is graphene powder. After ball milling, test the colloid viscosity and determine whether additional ball milling is needed based on the viscosity until the viscosity is within the range of 8000-10000 cP.

[0017] To use, mix components A and B in a 1:1 weight ratio, stir for 120 seconds, apply, and bake in an oven at 150°C for 8 hours to cure. For electrostatic chucks, mix and stir components A and B, then apply evenly to the bonding area between the ceramic plate and the aluminum base of the electrostatic chuck. Assemble the coated ceramic plate and aluminum base, apply pressure, and bake to cure.

[0018] The above method was used to prepare multiple groups of glues with different ratios, and the thermal conductivity, tensile strength, shear strength, high temperature resistance and density of the glue layers after curing of each group of glues were measured, as shown in the following Examples 1-6.

[0019] Example 1 This embodiment provides a glue for bonding a high-temperature electrostatic chuck, the raw material composition and weight parts of which are as follows: Component A: 39 parts of octamethylcyclotetrasiloxane, 35 parts of aluminum oxide, 4 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 2 parts of mica powder, 5 parts of aluminum nitride powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane; Component B: 39 parts of octamethylcyclotetrasiloxane, 35 parts of aluminum oxide, 4 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 2 parts of mica powder, 5 parts of graphene powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane.

[0020] The glue has been tested to have a thermal conductivity of 3.4 W / m·K, a tensile strength of 1.8 MPa, a shear strength of 1.3 MPa, a high temperature resistance of 320°C, and a density of 2.72 g / cm 3 The high temperature resistance is the highest temperature at which the glue does not crack.

[0021] Example 2 This embodiment provides a glue for bonding a high-temperature electrostatic chuck, the raw material composition and weight parts of which are as follows: Component A: 28 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 3 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 5 parts of mica powder, 8 parts of aluminum nitride powder, 5 parts of citrate, 4 parts of stannous octoate, and 2 parts of trimethylsilane.

[0022] Component B: 28 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 3 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 5 parts of mica powder, 8 parts of graphene powder, 5 parts of citrate, 4 parts of stannous octoate, and 2 parts of trimethylsilane.

[0023] The glue has been tested to have a thermal conductivity of 4.1 W / m·K, a tensile strength of 1.5 MPa, a shear strength of 1.1 MPa, a high temperature resistance of 375°C, and a density of 2.78 g / cm 3 .

[0024] Example 3 This embodiment provides a glue for bonding a high-temperature electrostatic chuck, the raw material composition and weight parts of which are as follows: Component A: 30 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 3 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 5 parts of mica powder, 8 parts of aluminum nitride powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane.

[0025] Component B: 30 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 3 parts of calcium carbonate, 3 parts of silicon oxide, 3 parts of polyimide, 5 parts of mica powder, 8 parts of graphene powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane.

[0026] The glue has been tested to have a thermal conductivity of 4.2 W / m·K, a tensile strength of 1.82 MPa, a shear strength of 1.32 MPa, a high temperature resistance of 410°C, and a density of 2.78 g / cm 3 .

[0027] Repeated verification with the same formula yielded the following test data: thermal conductivity 4.15 W / m·K, tensile strength 1.79 MPa, shear strength 1.28 MPa, high temperature resistance 400°C, density 2.76 g / cm 3 All indicators have a downward trend to varying degrees, indicating that the results of this formula are not stable enough.

[0028] Example 4 This embodiment provides a glue for bonding a high-temperature electrostatic chuck, the raw material composition and weight parts of which are as follows: Component A: 30 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 2.85 parts of calcium carbonate, 3.2 parts of silicon oxide, 3 parts of polyimide, 5.1 parts of mica powder, 8 parts of aluminum nitride powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane.

[0029] Component B: 30 parts of octamethylcyclotetrasiloxane, 39 parts of aluminum oxide, 2.85 parts of calcium carbonate, 3.2 parts of silicon oxide, 3 parts of polyimide, 5.1 parts of mica powder, 8 parts of graphene powder, 4 parts of citrate, 3 parts of stannous octoate, and 2 parts of trimethylsilane.

[0030] The glue has been tested to have a thermal conductivity of 4.18 W / m·K, a tensile strength of 1.84 MPa, a shear strength of 1.34 MPa, a high temperature resistance of 410°C, and a density of 2.79 g / cm 3 .

[0031] Repeated verification with the same formula yielded the following test data: thermal conductivity 4.17 W / m·K, tensile strength 1.85 MPa, shear strength 1.36 MPa, high temperature resistance 410°C, density 2.78 g / cm 3 It can be seen that the performance of the glue is relatively stable under this formula.

[0032] A comparative analysis of the above examples shows that as the content of aluminum nitride powder and graphene powder in the formula increases, the thermal conductivity of the glue significantly improves, but the strength decreases. In Examples 3-4, when the content of aluminum nitride powder and graphene powder both reaches 8 parts and the ratio of plasticizer and catalyst is reduced, the thermal conductivity of the glue stabilizes within the range of 4.1-4.2 W / m•K, and the high temperature resistance is also improved to around 410°C, showing excellent heat resistance stability. At the same time, the mechanical strength is also within the expected range. In Example 4, the amount of calcium carbonate, silicon oxide, and mica powder was slightly adjusted to ensure that the thermal conductivity and high temperature resistance, tensile strength, shear strength, and density of the glue are basically stable.

[0033] Through a specific raw material ratio and preparation process, the present invention has successfully developed a high-temperature electrostatic chuck adhesive with excellent overall performance. Using octamethylcyclotetrasiloxane as the base material and a specific filler system, the adhesive achieves a balance of high thermal conductivity, high temperature resistance, and mechanical strength. The adhesive is capable of withstanding temperatures exceeding 400°C, is resistant to aging and corrosion by plasma bombardment, and exhibits high thermal conductivity. These advantages make the adhesive particularly suitable for electrostatic chuck bonding applications requiring high temperatures and high thermal conductivity.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, shall be included in the scope of patent protection of the present invention. Those skilled in the art may modify the technical solutions described in the embodiments or make equivalent substitutions for some of the technical features therein without departing from the spirit and scope of the technical solutions of the present invention. Such modifications or substitutions shall be included in the scope of protection of the present invention.

Claims

1. A glue for bonding high-temperature electrostatic chucks, characterized in that: The raw materials of the glue are as follows by weight: 28-40 parts of octamethylcyclotetrasiloxane, 35-40 parts of aluminum oxide, 2-4 parts of calcium carbonate, 3-5 parts of silicon oxide, 2-4 parts of polymer filler, 2-5 parts of silicate, 5-8 parts of non-oxide filler, 3-6 parts of organic acid ester, 2-5 parts of tin catalyst, and 1-2 parts of silane coupling agent.

2. The high-temperature electrostatic chuck bonding glue according to claim 1, characterized in that: The non-oxide filler is one or a combination of aluminum nitride and graphene.

3. The glue for bonding high-temperature electrostatic chuck according to claim 2, characterized in that: The glue is divided into component A and component B, and both component A and component B contain octamethylcyclotetrasiloxane, aluminum oxide, calcium carbonate, silicon oxide, polymer filler, silicate, non-oxide filler, organic acid ester, tin catalyst and silane coupling agent; the non-oxide filler in component A is aluminum nitride, and the non-oxide filler in component B is graphene; the weight ratio of component A to component B is 1:

1.

4. The glue for bonding high-temperature electrostatic chuck according to claim 1, characterized in that: The polymer filler is polyimide.

5. The glue for bonding high-temperature electrostatic chuck according to claim 1, characterized in that: The silicate is mica powder.

6. The glue for bonding high-temperature electrostatic chuck according to claim 1, characterized in that: The tin catalyst is stannous octoate.

7. The glue for bonding high-temperature electrostatic chuck according to claim 1, characterized in that: The silane coupling agent is trimethylsilane.

8. The glue for bonding high-temperature electrostatic chucks according to claim 1, characterized in that: The organic acid ester is citrate.

9. A method for preparing the glue for bonding a high-temperature electrostatic chuck according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing powdered aluminum oxide and octamethylcyclotetrasiloxane and performing a first stage of ball milling; adding remaining raw materials to the mixture after the first stage of ball milling and performing a second stage of ball milling, wherein the non-oxide filler in the remaining raw materials is in powder form; the first stage of ball milling is performed for 6-10 hours, and the second stage of ball milling is performed for 12-20 hours, and the viscosity of the final colloid is controlled within the range of 8000-10000 cP.

10. Use of the glue for bonding a high-temperature electrostatic chuck according to any one of claims 1 to 8 in an electrostatic chuck, wherein the electrostatic chuck comprises a ceramic disc and an aluminum base, and the glue bonds the ceramic disc and the aluminum base to each other.