Organosilicon temporary bonding material easy to clean and preparation method and application thereof

Abstract

The invention provides an easy-to-clean organosilicone temporary bonding material and a preparation method and application thereof, and the easy-to-clean organosilicone temporary bonding material comprises the following components by weight: 40-70% of an organic solvent; 10%-25% of vinyl raw rubber; 10%-35% of hydrogen-containing silicone oil; 1%-5% of a reinforcing agent; 0.5 to 1 ppm of a catalyst; and 0.5%-1.5% of an inhibitor. Conventional vinyl silicone oil is abandoned, vinyl raw rubber is used as a crosslinking main body, the viscosity and stability of the product can be more efficiently regulated and controlled, meanwhile, a proper amount of reinforcing agent is added, the heat resistance and tensile property of the product are improved, the product has the advantages of organic silicon, the bonding requirement is met, and the production cost is reduced through a subsequent high-temperature process. And finally, the cleaning removal performance after de-bonding can also be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wafer production and processing, and relates to an easily cleanable silicone temporary bonding material, a preparation method thereof, and an application thereof. Background Art

[0002] As a process material in the entire semiconductor process, the temporary bonding material is the key to ensuring the smooth progress of the entire TBDB process. On the one hand, it is required to tightly bond the temporary carrier plate and the device wafer together, so that the device wafer can be effectively protected and supported, and can withstand harsh processing environments such as high temperature, high vacuum, mechanical pressure, and chemical corrosion in subsequent process steps; on the other hand, it is required to safely separate the temporary carrier plate and the device wafer by a simple and fast method after processing. Due to its excellent high-temperature resistance and chemical resistance, and good leveling property, which is easy to obtain a good film surface, silicone materials can be selected as the temporary bonding material.

[0003] CN114521211A discloses a double-layer structure in which a photocurable silicone material is spin-coated on a support plate and can be peeled off from the adhesive layer on the substrate. However, the material on the substrate is a thermoplastic material with slightly poor high-temperature resistance, and the warpage of the double-layer structure is unstable, affecting the processing yield.

[0004] US7541264L discloses a technology that uses a silicone adhesive for the temporary bonding material layer. However, it is a technology that uses a heat-curable silicone adhesive to bond the substrate and the support, and is immersed in a chemical reagent that dissolves or decomposes the silicone resin during peeling to separate the substrate from the support. Therefore, the peeling takes a very long time and is difficult to apply to actual production processes. Moreover, after peeling, it also takes a long time to clean the silicone adhesive remaining on the substrate as a residue, and there are also problems in terms of cleaning removability.

[0005] Therefore, in this field, it is desirable to develop a silicone temporary bonding material with excellent heat resistance and easy to clean. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, that is, the peeling performance and cleaning removability of the existing silicone resin after curing with the support plate and the substrate cannot meet the process requirements and other defects, the purpose of the present invention is to provide an easily cleanable silicone temporary bonding material, a preparation method thereof, and an application thereof. The silicone temporary bonding material provided by the present invention can improve the warpage of the wafer during bonding, has good cleaning removability, and has excellent tolerance to wafer thermal processes such as PECVD (chemical vapor deposition) and reflow soldering, and can improve the productivity of thin wafers.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an easily cleanable silicone temporary bonding material. The easily cleanable silicone temporary bonding material comprises the following components by weight percentage:

[0009]

[0010] The present invention does not use macromolecular vinyl silicone oil, but instead uses vinyl raw rubber as the crosslinking main body, which greatly facilitates the adjustment of the viscosity of the bonding material and is convenient for preparing adhesive liquids with different film thickness requirements. At the same time, the molecular chain of the raw rubber is longer and more stable. After adding a reinforcing agent and crosslinking and curing, a wider crosslinked region is formed, and when washed with a solvent, it tends to swell and peel off as a whole film.

[0011] The silicone temporary bonding material provided by the present invention is a clear and transparent liquid at room temperature storage and a colorless and transparent thin film after crosslinking and curing.

[0012] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the organic solvent can be 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, etc.

[0013] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the vinyl raw rubber can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 25%, etc.

[0014] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the hydrogen-containing silicone oil can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 35%, etc.

[0015] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the reinforcing agent can be 1%, 2%, 3%, 4%, 5%, etc.

[0016] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the catalyst can be 0.5 ppm, 0.6 ppm, 0.7 ppm, 0.8 ppm, 0.9 ppm, 1 ppm, etc.

[0017] In the present invention, for the easily cleanable silicone temporary bonding material by weight percentage, the amount of the inhibitor can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, etc.

[0018] Preferably, the organic solvent includes any one or a combination of at least two of cyclohexane, n-hexane, and ethylcyclohexane.

[0019] Preferably, the molecular weight of the vinyl raw rubber is 400,000 - 700,000, such as 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, etc.

[0020] Preferably, the vinyl content in the vinyl raw rubber is 0.03% - 3%, such as 0.03%, 0.3%, 3%, etc.

[0021] Preferably, the vinyl raw rubber includes any one or a combination of at least two of methyl-capped methyl vinyl raw rubber, vinyl-capped methyl vinyl raw rubber, methyl vinyl phenyl raw rubber, and methyl vinyl trifluoropropyl raw rubber.

[0022] Preferably, the hydrogen content of the hydrogen-containing silicone oil is 0.07 - 1.2 mmol / g, such as 0.07 mmol / g, 0.18 mmol / g, 0.20 mmol / g, 0.50 mmol / g, 1.2 mmol / g, etc.

[0023] Preferably, the reinforcing agent includes any one or a combination of at least two of vinyl MQ resin, methyl MQ resin, and octamethylcyclotetrasiloxane. For example, the reinforcing agent includes any one or a combination of at least two of Chenxi vinyl MQ resin (CX-355), Xinhou methyl MQ resin (AM-8026-2), Longsheng Sihai vinyl MQ resin (SH-5202), Delta vinyl MQ resin (DT-6901), and octamethylcyclotetrasiloxane.

[0024] Preferably, the catalyst includes a Pt catalyst.

[0025] Preferably, the inhibitor includes any one or a combination of at least two of 2-vinyl isopropanol, 2-ethynylbut-2-ol, 3-phenyl-1-butene-3-ol, 1-ethynyl-1-cyclopentanol, 1-ethynyl-1-cyclohexanol, and β-alkynol inhibitors.

[0026] In a second aspect, the present invention provides a method for preparing an easily cleanable silicone temporary bonding material as described in the first aspect. The preparation method includes the following steps:

[0027] (1) Mix the inhibitor, vinyl raw rubber, reinforcing agent, and organic solvent, and stir.

[0028] (2) Add the hydrogen-containing silicone oil to step (1), and stir until a clear and transparent liquid is formed.

[0029] (3) Add a catalyst to step (2), stir until a clear and transparent liquid is formed, and then perform post-treatment to obtain the easily cleanable silicone temporary bonding material.

[0030] Preferably, the rotation speed of the stirring in step (1) is 100 - 400 rpm, such as 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, etc., and the stirring time is 2 - 3 h, such as 2 h, 2.5 h, 3 h, etc.

[0031] Preferably, the rotation speed of the stirring in step (2) is 100 - 400 rpm, such as 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, etc., and the stirring time is 0.5 - 1.5 h, such as 0.5 h, 1 h, 1.5 h, etc.

[0032] Preferably, the rotation speed of the stirring in step (3) is 100 - 400 rpm, such as 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, etc., and the stirring time is 4 - 6 h, such as 4 h, 4.5 h, 5 h, 5.5 h, 6 h, etc.

[0033] Preferably, the post-treatment in step (3) includes filtration.

[0034] Preferably, the precision grade of the filter element used for the filtration is 5 - 10 μm, such as 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc.

[0035] In the third aspect, the present invention provides an application of the easily cleanable silicone temporary bonding material as described in the first aspect in a wafer processing process.

[0036] Preferably, the method of the application includes the following steps:

[0037] 1) Place the wafer on a spin coater, spin coat the easily cleanable silicone temporary bonding material on the wafer, and bake.

[0038] 2) Bond the coated surface of the baked wafer and the glass sheet coated with a laser release material to the surface of the carrier stage, evacuate, heat, apply pressure, bond, and cool to room temperature to complete the temporary bonding of the wafer.

[0039] 3) Perform a backside process on the bonded pair, use laser release to unload the wafer, and clean the surface of the wafer with a cleaning agent to complete the construction of the easily cleanable silicone temporary bonding material.

[0040] Preferably, the spin coating in step 1) includes: first spin coating at a spin coating rate of 400 - 800 rpm (such as 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, etc.) for 60 - 90 s (such as 60 s, 65 s, 70 s, 75 s, 80 s, 85 s, 90 s, etc.), and then spin coating at a spin coating rate of 1500 - 2000 rpm (such as 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, 1750 rpm, 1800 rpm, 1850 rpm, 1900 rpm, 1950 rpm, 2000 rpm, etc.) for 2 - 5 s, such as 2 s, 3 s, 4 s, 5 s, etc.

[0041] Preferably, the baking temperature in step 1) is 60 - 90 °C (such as 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, etc.), and the baking time is 4 - 8 min (such as 4 min, 5 min, 6 min, 7 min, 8 min, etc.).

[0042] Preferably, the heating in step 2) is to heat to 180 - 220 °C (such as 180 °C, 185 °C, 190 °C, 195 °C, 200 °C, 205 °C, 210 °C, 215 °C, 220 °C, etc.).

[0043] Preferably, the pressurization in step 2) is to pressurize to 0.1 - 0.2 KN (such as 0.1 KN, 0.15 KN, 0.2 KN, etc.).

[0044] Preferably, the bonding time in step 2) is 5 - 10 min (such as 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.).

[0045] Preferably, the backside process in step 3) includes processes such as grinding, polishing, photolithography, baking, chemical vapor deposition, etc.

[0046] Preferably, the laser wavelength in step 3) is 330 - 360 nm (such as 330 nm, 340 nm, 350 nm, 360 nm, etc.).

[0047] Preferably, the cleaning method in step 3) includes spraying or immersion.

[0048] Exemplarily, the method of the application includes the following steps:

[0049] Step 1: Place a 12-inch wafer on the spin coater, turn on the vacuum system, fix the wafer with the chuck, pour 40 - 50 mL of the easily cleanable silicone temporary bonding material evenly on the wafer, turn on the spin coating, and set the spin coating rate as follows: first spin coat at a rate of 400 - 800 rpm for 60 - 90 s, and then spin coat at a rate of 1500 - 2000 rpm for 2 - 5 s;

[0050] Step 2: Turn off the vacuum chuck, remove the wafer coated with silicone, and place it in an oven at 60 - 90 °C for baking for 4 - 8 min, preferably 5 min;

[0051] Step 3: Bond the coated side of the baked wafer and the glass sheet coated with release material to the surface of the carrier stage, evacuate, heat to 180 - 220 °C, apply a pressure of 0.1 - 0.2 KN, and bond for 5 - 10 min (preferably 10 min). After cooling to room temperature, the temporary bonding of the wafer is completed;

[0052] Step 4: Perform backside processes such as grinding, polishing, lithography, baking, chemical vapor deposition, etc. on the bonded pair. Use laser debonding to unload the wafer. The laser wavelength range is 330 - 360 nm. Use Huaxun Remover3 as the cleaning agent, and clean the residual glue on the wafer surface by spraying or immersion. Then use a stripping solution to remove a small amount of small molecule residues.

[0053] Compared with the prior art, the present invention has at least the following beneficial effects:

[0054] The present invention abandons conventional vinyl silicone oil and uses vinyl raw rubber as the crosslinking main body, which can more efficiently control the viscosity and stability of the product. At the same time, an appropriate amount of reinforcing agent is added to improve the heat resistance and tensile properties of the product, making the product have the advantages of silicone, meeting the bonding requirements, and being able to pass through subsequent high-temperature processes. Finally, it can also improve the cleaning and removal performance after debonding. Detailed Embodiments

[0055] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0056] Unless otherwise specified, the information of some raw materials involved in the following specific embodiments of the present invention is shown in Table 1 below. For other raw materials not shown, they are all conventional materials in the art and can be obtained through commercially available products.

[0057] Table 1

[0058] Material Grade Vinyl raw rubber 110-7, RBG0730 Vinyl silicone oil DOWSIL2-8566 Hydrogen-containing silicone oil MH-300, CX-350D Reinforcing agent DT-6901, Octamethylcyclotetrasiloxane Pt catalyst ZX-BJ01, Inhibitor 2-Ethynylbut-2-ol

[0059] Examples 1 - 8, Comparative Example 1

[0060] In Examples 1 - 8 and Comparative Example 1, a silicone temporary bonding material was provided respectively. The preparation raw materials and their dosages are shown in Table 2. In Table 2, the dosage range of each component is "g". Octamethylcyclotetrasiloxane is abbreviated as "D4"; the amounts of the catalyst and inhibitor are not shown in Table 2. The dosage of the catalyst is 0.5 - 1 ppm of the total weight of the preparation raw materials (the usage amount of the catalyst depends on the concentration and will be diluted when used. The usage amount is small and will not affect the total mass, so there is no specific value), and the dosage of the inhibitor is 0.5% of the total weight of the preparation raw materials.

[0061] Table 2

[0062]

[0063] The preparation method includes the following steps:

[0064] (1) Mix the inhibitor, vinyl raw rubber (or vinyl silicone oil), reinforcing agent, and organic solvent, and stir at a speed of 300 rpm for 3 h;

[0065] (2) Add hydrogen-containing silicone oil to step (1), and stir at a speed of 400 rpm for 1 h to form a clear and transparent liquid;

[0066] (3) Add the catalyst to step (2), and stir at a speed of 350 rpm for 3 h to form a clear and transparent liquid, then filter to obtain the easily cleanable silicone temporary bonding material.

[0067] Perform performance tests on the silicone temporary bonding materials provided in the examples and the comparative example. The test methods are as follows:

[0068] (1) Film surface condition: Spin-coat the silicone temporary bonding material according to the same parameters (800 rpm, 90 s), cure it, and preliminarily observe the film surface; a film thickness tester can be used to measure the film surface uniformity, and the film surface TTV is preferably less than 3 μm.

[0069] (2) Spin-coat the silicone temporary bonding material, pre-bake it, bond the wafer coated with this material to a glass sheet coated with a laser debonding material of the same size. Bonding pair condition: Observe the center and edge of the bonding pair under a microscope, and it is preferably free of defects such as chipping and snowflake-like bubbles.

[0070] (3) Take out the bonding pair and put it into a nitrogen oven to simulate a high-temperature process environment. Specific parameters: After heating from 25°C to 250°C, keep it warm for 2 h and then cool down to 25°C, and cycle 3 times. It is preferably that the film surface of the bonding pair remains smooth, without bubble bulges and no cracks at the edges.

[0071] (4) Take out the bonded pair, use a laser debonding device to remove the bonded pair, and perform a cleaning test using the self-made cleaning agent (Remover3) of Huaxun: Immerse the debonded wafer in the cleaning agent, take it out after ultrasonic cleaning for within 10 minutes, rinse, dry, and observe the wafer surface under a microscope. It is better if there is no residue of the glue dots.

[0072] The performance test results are shown in Table 3.

[0073] Table 3

[0074] Serial number Film surface Bonding test 250°C, 2h experiment Cleaning test / min Example 1 ○ ○ ○ 5 Example 2 ○ ○ ○ 4 Example 3 ○ ○ ○ 6 Example 4 ○ ○ ○ 3.5 Example 5 ○ ○ ○ 5 Example 6 ○ ○ ○ 4 Example 7 ○ ○ ○ 6 Example 8 ○ ○ ○ 5 Comparative example 1 ○ ○ × >10

[0075] # If the test result is excellent or the effect is good, the evaluation is "○"; if the test result has defects or the effect is poor, the evaluation is "×".

[0076] As can be seen from Table 3, the silicone-based temporary bonding materials provided by the embodiments of the present invention all have good heat resistance and good cleaning and removal performance after debonding.

[0077] Compared with Example 1, the silicone-based temporary bonding material provided in Comparative Example 1 uses vinyl silicone oil as the cross-linking main body, its heat resistance becomes worse, and the cleaning test also fails to meet the standard.

[0078] The applicant declares that the present invention uses the above embodiments to illustrate the easily cleanable silicone-based temporary bonding material and its preparation method and application, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An easy-to-clean organosilicon temporary bonding material, characterized in that: The easy-to-clean organic silicon temporary bonding material comprises the following components by weight percentage:

2. The easy-to-clean organosilicon temporary bonding material according to claim 1, characterized in that: The organic solvent includes any one of cyclohexane, n-hexane, and ethylcyclohexane, or a combination of at least two of them.

3. The easy-to-clean organic silicon temporary bonding material according to claim 1 or 2, characterized in that: The molecular weight of the vinyl rubber is 400,000 to 700,000; Preferably, the vinyl content in the vinyl raw rubber is 0.03% to 3%; Preferably, the vinyl raw rubber includes any one of methyl-terminated methyl vinyl raw rubber, vinyl-terminated methyl vinyl raw rubber, methyl vinyl phenyl raw rubber, and methyl vinyl trifluoropropyl raw rubber, or a combination of at least two thereof.

4. The easy-to-clean organosilicon temporary bonding material according to any one of claims 1 to 3, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is 0.07-1.2 mmol / g.

5. The easy-to-clean organosilicon temporary bonding material according to any one of claims 1 to 4, characterized in that: The reinforcing agent includes any one of vinyl MQ resin, methyl MQ resin, and octamethylcyclotetrasiloxane, or a combination of at least two of them.

6. The easy-to-clean organosilicon temporary bonding material according to any one of claims 1 to 5, characterized in that: The catalyst comprises a Pt catalyst; Preferably, the inhibitor includes any one of 2-vinyl isopropanol, 2-ethynylbutan-2-ol, 3-phenyl-1-butene-3-ol, 1-ethynyl-1-cyclopentanol, 1-ethynyl-1-cyclohexanol, and β-alkynol inhibitors, or a combination of at least two thereof.

7. A method for preparing an easy-to-clean organosilicon temporary bonding material as claimed in any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: (1) Mixing the inhibitor, vinyl rubber, reinforcing agent and organic solvent and stirring; (2) adding hydrogen-containing silicone oil to step (1) and stirring; (3) adding a catalyst to step (2), stirring, and post-processing to obtain the easy-to-clean organosilicon temporary bonding material.

8. The preparation method according to claim 7, characterized in that: The stirring speed in step (1) is 100 to 400 rpm, and the stirring time is 2 to 3 hours; Preferably, the stirring speed in step (2) is 100 to 400 rpm, and the stirring time is 0.5 to 1.5 h; Preferably, the stirring speed in step (3) is 100 to 400 rpm, and the stirring time is 4 to 6 hours; Preferably, the post-processing in step (3) comprises filtration; Preferably, the filter element used for the filtration has a precision grade of 5 to 10 μm.

9. Use of the easy-to-clean organic silicon temporary bonding material according to any one of claims 1 to 6 in a wafer processing technology.

10. The use according to claim 9, characterized in that: The method of application comprises the following steps: 1) placing a wafer on a spin coater, spin coating the easy-to-clean organic silicon temporary bonding material on the wafer, and baking; 2) Lay the adhesive coated surface of the baked wafer and the glass sheet coated with the laser debonding material on the surface of the wafer stage, evacuate, heat, pressurize, bond, and cool to room temperature to complete the temporary bonding of the wafer; 3) performing back processing on the bonded pair, using laser debonding to remove the wafer, and cleaning the surface of the wafer with a cleaning agent to complete the construction of the easy-to-clean silicone temporary bonding material; Preferably, the spin coating in step 1) comprises: firstly spinning at a spin coating rate of 400 to 800 rpm for 60 to 90 s, and then spinning at a spin coating rate of 1500 to 2000 rpm for 2 to 5 s; Preferably, the baking temperature in step 1) is 60-90° C. and the baking time is 4-8 min. Preferably, the heating in step 2) is heating to 180-220° C.; Preferably, the pressurization in step 2) is pressurized to 0.1-0.2 KN; Preferably, the bonding time in step 2) is 5 to 10 minutes; Preferably, the backside process in step 3) includes grinding, polishing, photolithography, baking, and chemical vapor deposition; Preferably, the wavelength of the laser in step 3) is 330-360 nm; Preferably, the cleaning method in step 3) includes spraying or soaking.

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