A method for composite cleaning of semiconductor equipment shutter and cold plate

Abstract

The application discloses a composite cleaning method for semiconductor equipment Shutter and Cold plate, and belongs to the technical field of semiconductor packaging testing. The model discards the rigid logic in the prior art that multiple groups of models must pass all at once or the process is terminated, and proposes a new algorithm model with stronger fault tolerance. The core is to configure a backup coordinate set for each group of point matching models. When the main coordinate fails to judge, the backup set is automatically enabled to continue to try, instead of immediately terminating the process. At the same time, an image rotation compensation mechanism and an extended normal core particle appearance template library are introduced in the judgment process to improve the success rate of single judgment. The application effectively solves the problem of automatic point matching failure caused by chip falling off and slight appearance abnormalities. The application can significantly improve the automatic point matching success rate of the handler to more than 95%, greatly improving the automatic point matching success rate and equipment utilization rate of the handler, and is especially suitable for the sorting scene of small-size chips such as Mini LED.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment maintenance technology, specifically to a composite cleaning method for the shutter and cold plate in molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD) equipment. Background Technology

[0002] In semiconductor thin film epitaxial growth equipment (such as MBE and MOCVD), the shutter and cold plate are key mechanical components. The shutter is used to absorb residual heat from the environment and protect the chamber walls, while the cold plate precisely controls the molecular beam to optimize gas flow. These components are exposed to high temperature, high vacuum, and reactive gas environments for extended periods during operation.

[0003] As the equipment operates for longer periods, deposits gradually accumulate on the surfaces of the shutter and cold plate, as well as in the internal cooling water channels. These deposits mainly include: unreacted decomposition products of metal-organic sources (MO sources), polymeric byproducts of the reaction, and metal particles volatilized from components such as heating wires. Especially in the internal cooling water channels, where the water flow is slow and the temperature gradient is large, a dense scale layer is easily formed.

[0004] Currently, there is no cleaning solution for the Shutter and Cold Plate. However, neglecting to clean and maintain them will inevitably lead to the following technical drawbacks:

[0005] (1) Lack of cleaning process leads to blockage and cracking: As described in the background section of this application, there is currently no effective in-situ cleaning solution. Long-term lack of cleaning leads to the gradual thickening of deposits in the internal water channels and a decrease in cooling water flow. According to the monitoring data of this application, the flow rate of the cold plate water channel before cleaning was only 28L / min, while the initial design value was 36-37L / min, a decrease of more than 22%.

[0006] (2) Thermal stress concentration leads to component cracking: Water channel blockage leads to a decrease in local cooling effect, and hot spots appear between the Shutter and the Coldplate. During the repeated heating and cooling thermal cycle, huge thermal stress is generated between the hot spots and the normal cooling area. Long-term accumulation leads to material fatigue, eventually causing microcracks to develop and propagate. Before cleaning, the highest temperature of the Coldplate reached 62.53℃, which was significantly higher than the initial design temperature (60-61℃).

[0007] (3) High maintenance costs: The cost of replacing the Shutter and Cold Plate due to cracking is extremely high, and frequent replacement of parts seriously affects the utilization rate of the equipment.

[0008] Therefore, there is an urgent need for a combined cleaning method for semiconductor device shutters and cold plates. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a composite cleaning method for a semiconductor device shutter and a cold plate.

[0010] This invention is achieved through the following technical solution:

[0011] A composite cleaning method for the shutter and cold plate of semiconductor devices includes the following steps:

[0012] Step 1, Disassembly and Placing: Remove the Shutter and Cold Plate to be cleaned from the semiconductor equipment and place them into the ultrasonic cleaning tank as a whole, ensuring that the Shutter and Cold Plate are completely immersed in the cleaning solution;

[0013] Step 2, Cleaning solution preparation: Pour the prepared cleaning solution into the ultrasonic cleaning tank, ensuring the liquid level is 5-10cm above the highest point of the top cover;

[0014] Step 3: Internal water circulation cleaning: Connect the inlet and outlet pipes of the circulation pump to the cooling water inlet and outlet of the Shutter and Coldplate respectively to form a closed circulation loop; start the circulation pump to force the cleaning fluid to circulate in the internal water circuit, and control the circulation pump flow rate at 5-10L / min.

[0015] Step 4, Ultrasonic Cleaning: Start the ultrasonic generator, control the ultrasonic power at 200-1000W, and apply ultrasonic vibration to the cleaning solution in the ultrasonic cleaning tank; at the same time, maintain the internal water circulation of Step 3, and clean inside and outside simultaneously for 3-5 hours.

[0016] Step 5, External Rinse: After cleaning, use a water gun to thoroughly rinse the outer surface and internal water channels of the Shutter and Cold Plate to remove residual cleaning solution and loose dirt.

[0017] Step 6, Ultrasonic tank water replacement: Perform three-stage water replacement rinsing on the ultrasonic cleaning tank: change the water every half hour, and rinse continuously for 3-5 hours using the overflow method to ensure complete removal of chemical residues;

[0018] Step 7, Drying: After washing, use high-purity nitrogen (GN2) to blow the inside and outside of the Shutter and Cold plate, and wipe the surface with a lint-free cloth; put the parts into an oven and bake at 100-120℃ for 3-5 hours to completely remove moisture;

[0019] Step 8, Leak Detection and Testing: After baking, perform a sealing test on the Shutter and Cold Plate; test the cooling water flow rate to confirm that it has been restored to the initial design value.

[0020] Preferably, the cleaning solution in step two is one of the following formulations:

[0021] Formula A (acidic cleaning solution): oxalic acid aqueous solution, wherein the oxalic acid mass concentration is 20-30%, and the balance is deionized water.

[0022] Formula B (Alkaline Oxidative Cleaning Solution): A mixed aqueous solution containing 5-15% hydrogen peroxide and 10-30% ammonia by volume, with the remainder being deionized water.

[0023] Preferably, the internal and external simultaneous cleaning time in step four is 4 hours.

[0024] Preferably, in step seven, the oven drying conditions are 120°C for 4 hours to completely remove moisture from the components.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention employs a composite cleaning mechanism: external ultrasonic cavitation combined with internal circulating rinsing, achieving synergistic cleaning without dead angles; it utilizes a dual chemical formulation system: Option A, oxalic acid + deionized water, and Option B, hydrogen peroxide + ammonia + deionized water, allowing for flexible selection based on deposit type to achieve targeted cleaning and synergistic chemical effects; optimized parameter combination: the optimal parameter range (i.e., ultrasonic power 200-1000W, circulation flow rate 5-10L / min, cleaning time 4h, baking temperature 120℃ / 4h) determined through extensive experiments ensures effective cleaning without damaging the substrate; environmentally friendly and water-saving: a three-stage clean water replacement + overflow rinsing process ensures no chemical residue after cleaning.

[0027] After cleaning the shutter and cold plate of the semiconductor device using the method of this invention, the device achieves the following results:

[0028] (1) Completely restore cooling performance: After cleaning, the water flow rate recovered from 28L / min to 36L / min, with a recovery rate of over 98%, basically reaching the initial design value (36-37L / min).

[0029] (2) Significantly reduced operating temperature: After cleaning, the highest temperature of the top cover dropped from 62.53℃ to 60.83℃, a decrease of 1.7℃, returning to the design temperature range (60-61℃).

[0030] (3) Effectively prevent cracking: By removing blockages and restoring uniform cooling, the heat stress concentration points are eliminated, preventing heat stress cracking from the root cause. It is expected that the service life of the component can be extended by 2-3 times.

[0031] (4) Surface repair and corrosion protection: The deposits on the outer surface are completely removed, and the micro-corrosion products and attachments on the surface are removed, which fundamentally blocks the conditions for corrosion to occur and extends the service life of the components. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the process structure of the cleaning method of the present invention. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings:

[0034] As shown in the attached diagram, the cleaning steps of this invention are as follows:

[0035] Table 1

[0036]

[0037] The method of this invention was used to clean the Shutter and Cold Plate. The key parameters before and after cleaning are compared in Tables 2 and 3 below:

[0038] Option 1 (Oxalic Acid Cleaning) Cleaning Data Table 2

[0039]

[0040] Option 2 (Hydrogen peroxide + ammonia cleaning) Cleaning data table 3

[0041]

[0042] The cleaning effect verification data is shown in Table 4 below (taking Cold Plate as an example):

[0043]

[0044] The durability test results are shown in Table 5 below:

[0045]

[0046] The results showed that the flow rate did not decrease significantly after cleaning by either scheme, and the cleaning effect was long-lasting.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A composite cleaning method for the shutter and cold plate of a semiconductor device, characterized in that, Includes the following steps: Step 1, Disassembly and Placing: Remove the Shutter and Cold Plate to be cleaned from the semiconductor equipment and place them into the ultrasonic cleaning tank as a whole, ensuring that the Shutter and Cold Plate are completely immersed in the cleaning solution; Step 2, Cleaning solution preparation: Pour the prepared cleaning solution into the ultrasonic cleaning tank, ensuring the liquid level is 5-10cm above the highest point of the top cover; Step 3: Internal water circulation cleaning: Connect the inlet and outlet pipes of the circulation pump to the cooling water inlet and outlet of the Shutter and Coldplate respectively to form a closed circulation loop; start the circulation pump to force the cleaning fluid to circulate in the internal water circuit, and control the circulation pump flow rate at 5-10L / min. Step 4, Ultrasonic Cleaning: Start the ultrasonic generator, control the ultrasonic power at 200-1000W, and apply ultrasonic vibration to the cleaning solution in the ultrasonic cleaning tank; at the same time, maintain the internal water circulation of Step 3, and clean inside and outside simultaneously for 3-5 hours. Step 5, External Rinse: After cleaning, use a water gun to thoroughly rinse the outer surface and internal water channels of the Shutter and Cold Plate to remove residual cleaning solution and loose dirt. Step 6, Ultrasonic tank water replacement: Perform three-stage water replacement rinsing on the ultrasonic cleaning tank: change the water every half hour, and rinse continuously for 3-5 hours using the overflow method to ensure complete removal of chemical residues; Step 7, Drying: After washing, use high-purity nitrogen (GN2) to blow the inside and outside of the Shutter and Cold plate, and wipe the surface with a lint-free cloth; put the parts into an oven and bake at 100-120℃ for 3-5 hours to completely remove moisture; Step 8, Leak Detection and Testing: After baking, perform a sealing test on the Shutter and Cold Plate; test the cooling water flow rate to confirm that it has been restored to the initial design value.

2. The composite cleaning method for the shutter and cold plate of a semiconductor device according to claim 1, characterized in that, The cleaning solution in step two is one of the following formulations: Formula A (acidic cleaning solution): oxalic acid aqueous solution, wherein the oxalic acid mass concentration is 20-30%, and the balance is deionized water; Formula B (Alkaline Oxidative Cleaning Solution): A mixed aqueous solution containing 5-15% hydrogen peroxide and 10-30% ammonia by volume, with the remainder being deionized water.

3. The composite cleaning method for the shutter and cold plate of a semiconductor device according to claim 1, characterized in that, The simultaneous internal and external cleaning in step four takes 4 hours.

4. The composite cleaning method for the shutter and cold plate of a semiconductor device according to claim 1, characterized in that, In step seven, the oven drying conditions are 120°C for 4 hours to completely remove moisture from the components.

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