TW200533429A - Cleaning device implemented in a cleaning liquid circulation system capable of extending filter lifespan - Google Patents

Abstract

This invention discloses a cleaning device implemented in a cleaning liquid circulation system capable of extending filter lifespan. The cleaning device is installed in a cleaning liquid circulation system. The cleaning device includes a secondchamber that is installed therein with a mixture of hydrofluoric acid, hydrogen peroxide and hydrochloric acid, and is connected to two control valves installed to the cleaning liquid circulation system by a piping. Moreover, the mixture in the second chamber flows and circulatesthrough the filter in the cleaning liquid circulation system through a second pump so as to effectively clean the filter. The structural design of this invention can effectively prolong the lifespan of the filter in the cleaning circulation system and enhance cleaning effect.

Description

200533429 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a technology that can improve the life of a filter of a semiconductor integrated circuit cleaning process, and particularly relates to a filter that can be extended in a cleaning liquid circulation system. Lifetime cleaning device. [Previous technology] In the sub-micron wafer process, whether it is thin film deposition, high-temperature furnace tube diffusion, oxidation, or wafer surface treatment after #etching, it needs to go through a lot of high-purity chemical cleaning processes, The step of washing with pure water and finally drying with isopropyl alcohol. Semiconductor cleaning is mainly multi-tank cleaning. The American Radio Corporation (RCA) cleaning formula, which has been developed since the early 1960s, has been used to this day. Although different application methods have been continuously developed in each module, Only a few adjustments were made in the proportion of chemicals and the order of cleaning. The RC A cleaning process mainly includes three steps: 1. H 2S 0 4+ Η 20 2 (S PM), which is a caroic acid produced by sulfuric acid and hydrogen peroxide. Its strong oxidizing and dehydrating properties can destroy organic matter. The main purpose of carbon-hydrogen bonding is to remove photoresist. 2. ΝΗ40Η + Η 20 2 + Η20 (APM, also known as SC-1 or ΗΑ), which uses the weak alkali of ammonium hydroxide to activate the surface of silicon wafers and particles, so that the wafer surface and the particles repel each other to reach For the purpose of cleaning, hydrogen peroxide can also oxidize the surface of the silicon wafer, and the micro-etching of silicon dioxide by hydrogen peroxide can achieve the effect of removing particles; the purpose of this cleaning step is to remove organic pollution and particles. 3. HC1 + H 20 2 + H20 (HPPM, also known as SC-2 or HB), which uses peroxide

Page 6 200533429 V. Description of the invention (2) The metal contaminated by hydroxide is dissolved with hydrochloric acid and metal ions to form soluble chloride and dissolved, so the purpose of this crystal washing step is to remove metal contamination. The cleaning liquid in the cleaning process is performed in a cyclic manner, and filtered by a filter to remove impurities or contamination in the cleaning liquid. However, with the increase of component accumulation, the requirements of the Semiconductor Industry Association (SIA) on wafer quality, such as residual metal, anion (anion) ions, oxygen, organics, particles, etc., are gradually increasing, and cleaning fluid The frequency of replacement of the filters used in the circulation system has increased accordingly. The cleaning method and device of the transition device have been found in the previous case of China Patent Bulletin No. 4 2 193, this case uses a pressure control device, and uses a ring cap, a check piece, a check ring, a filter, etc. Form a filtration system for cleaning. However, the structure of the previous case is complicated, and the composition of the solution in the tank or pipeline is not described, and the cleaning effect is very limited. In view of this, the present invention proposes a cleaning device which can be used to extend the life of a filter in a cleaning liquid circulation system, so as to extend the life of the filter and the filter and improve the cleaning effect. [Summary of the invention] The main purpose of the present invention is to provide a cleaning device which can be used in a cleaning liquid circulation system to extend the life of the filter. The cleaning device is further provided with a cleaning device on the cleaning liquid circulation system. Hydrogen and hydrochloric acid mixed liquid to clean the filter to effectively remove particles of silicon dioxide, silicon and its compounds, metals and their compounds, organic types, etc., and thereby obtain a better cleaning effect, thereby extending the life of the filter . Another object of the present invention is to use a simple structure design to extend the service life of the filter in the SC-1 cleaning cycle system and improve the cleaning effect.

200533429 V. Description of the invention (3) The effect of fruit. In order to achieve the above object, the present invention adds a cleaning device to a cleaning liquid circulation system. The cleaning device includes a second containing tank, and a mixed solution of hydrofluoric acid, hydrogen peroxide, and hydrochloric acid is installed therein. The second receiving tank is connected to the second control valve of the cleaning liquid circulation system by using a pipeline connection, and a second pump is used to circulate the mixed liquid in the second receiving tank through the pipeline to flow through the cleaning. Filter in the liquid circulation system to effectively clean the filter. In the following, detailed descriptions will be made with specific embodiments and accompanying drawings to make it easier to understand the purpose, technical content, features and functions of the present invention. [Embodiment] The present invention is to add a cleaning device to a cleaning liquid circulation system, and use a mixed solution of hydrofluoric acid, hydrogen peroxide and hydrochloric acid in the cleaning device to clean the filter to effectively remove silicon dioxide, Particles or impurities of silicon and its compounds, metals and their compounds, organic types, etc. Please refer to the first figure, which is a schematic diagram of adding a cleaning device to a cleaning liquid circulation system for a semiconductor integrated circuit RCA cleaning process. The cleaning liquid circulation system includes a first receiving tank 10, A mixed liquid (SC-1) of ammonium hydroxide (NH 40H), hydrogen peroxide (Η200) and ultrapure water (D · I · water) is placed in the system as a cleaning solution; and a pipeline is used. 1 2 Connect a heater 1 4, a first control valve 16, a filter 18, a second control valve 20 and a first pump 22 respectively, so as to form a circulation for cleaning liquid circulation. Circuit to make the first receiving tank with the first pump 2 2

Page 8 200533429 V. Description of the invention (4) The cleaning liquid in 10 flows and circulates through the filter to remove impurities from the cleaning liquid, such as silicon, silicon dioxide, metal, organic matter, dust, etc., and by the heating The heating of the device 14 keeps the cleaning liquid at a temperature of 25 ~ 90 ° C, and the two control valves 16 and 20 are respectively located on the lines 12 on the two sides of the filter 18, so that Automatic timer or manual operation to control the circulation or non-circulation of the cleaning solution. Among them, another bypass cleaning device 24 is installed on the first control valve 16 and the second control valve 20, which is composed of a second receiving tank 26 and a second pump 28. A mixed liquid of hydrofluoric acid, hydrogen peroxide and hydrochloric acid is installed in the second receiving tank 26, and the second receiving tank 2 6 is connected to the second control valve installed in the cleaning liquid circulation system by using a pipe 12 ' 16 and 20, and can use the two control valves 16 and 20 to control the flow of the mixed liquid, and the mixed liquid in the second holding tank 26 is through the second pump 28 in the pipeline 1 2 ′ circulates through the filter 18 between the two control valves 16 and 20. Hydrofluoric acid, hydrogen peroxide, and hydrochloric acid in the mixed liquid in the second holding tank 26 above are all semiconductor grades, and the hydrofluoric acid is a diluted hydrofluoric acid, and the hydrofluoric acid is The dilution ratio of acid to water is between 1:10 and 1: 100. In addition, the material of the second pump 28 is a pump capable of resisting the mixed solution of hydrofluoric acid, hydrogen peroxide and hydrochloric acid; and the above-mentioned cleaning liquid circulation system and cleaning device 2 4 are used in the pipeline 1 2, 1 2 The material is made of polyvinylidene fluoride (PVDF), perfluorooxyethylene ether (PFA) or polyetheretherketone (PEEK). When the cleaning liquid in the above-mentioned cleaning liquid circulation system needs to be replaced, please refer to the second figure. First, the cleaning liquid in the first storage tank 10 is mixed with hydrogen hydroxide, hydrogen peroxide and ultrapure water. Drain the liquid and add ultrapure water to

200533429 V. Description of the invention (5) Inside the first receiving tank 10; then start the first pump 22 and open the control valves 16 and 20 so that the pipeline 12 forms a passage to clean the circulation system. At this time, the heater 1 4 is temporarily not heated, and only the pipeline is kept in circulation. The second receiving tank 26 and the second pump 28 of the other bypass cleaning device 2 4 are in an idle state at this time. When you want to clean the filter 18 in the cleaning liquid circulation system, please refer to the third figure to make the first pump 22, the heater 14 and the first storage tank 10 in an idle state; start the second pump 2 8 And open the first control valve 16 and the second control valve 20 to form another passage by using the pipeline 12 ′, and use a mixture of hydrofluoric acid, hydrogen peroxide and hydrochloric acid in the second accommodation tank 26. Liquid to clean the filter 18 to clean the filter 18. Among them, hydrofluoric acid will react with silicon dioxide in the cleaning solution to generate silicon tetrafluoride gas; hydrogen peroxide can oxidize silicon and inactive metal particles in the cleaning solution to decompose light organic particles; hydrochloric acid can dissolve active metals And particles of metal compounds. Therefore, after the cleaning liquid passes through the second containing tank, particles are greatly reduced; when the cleaning liquid passes through the filter, the number of particles is small, and the probability of the filter being blocked is reduced, so that the service life of the filter is naturally extended. And the impurity part of the cleaning liquid is decomposed, and when the cleaning liquid flows into the first holding tank again, the cleaning effect can be effectively improved. The invention uses a hydrofluoric acid, hydrogen peroxide and hydrochloric acid mixed liquid to increase the service life of the filter. The chemical mechanism of this mixed liquid is as follows: 1. Hydrofluoric acid dissolves silicon dioxide:

Si02 + HF- > H2SiF6 + 2H20 H2SiF6 (solution)-> SiF4 (gas) + 2HF (liquid) 2. Hydrogen peroxide oxidizes silicon and inactive metals in acidic solutions and decomposes

Page 10 200533429 V. Description of the invention (6) Organic particles:

Si- Si 1 + 4e

Si 4Η2Η2α- Si02 + 4H +, its exothermic reaction △ G =-3 4 0 KJ / m ο 1 e H2〇2 + 2HH2e- > 2H2〇 The comprehensive reaction of the first three reaction formulas is S l + 2 H 20 2— S i 0 2+ 2 H 20 C u (solid state) —C u 2+ (solution) + 2e—, the endothermic reaction AG = 65.5 KJ / mole The above comprehensive reaction is (: 1) (solid state) +1] 2. 2 + 211— (solution) — (: 112 ++ 2 [120, total heat of this reaction Δ G = -275 KJ / mole 3. Hydrochloric acid dissolves metal compound particles:

Mx0y + 2yH ^ xM (2y / x) ++ yH20 Μ (0Η) x + x Bu Mx ++ 0. 5xH20 In summary, the design of adding a cleaning device to the cleaning liquid circulation system of the present invention can effectively remove two Particles of silicon oxide, silicon and its compounds, metals and their compounds, and organic matter types, to obtain better cleaning results, and to extend the life of the filter. Therefore, the present invention uses a simple structural design to achieve the effect of extending the service life of the filter in the SC-1 cleaning cycle system and improving the cleaning effect. The above-mentioned embodiments are only for explaining the technical ideas and characteristics of the present invention. The purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. When the scope of the patent of the present invention cannot be limited, That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention should still be covered by the patent scope of the present invention. [Illustration of drawing number]

Page 11 200533429 14 Heater 16 First control valve 18 Filter 20 Second control valve 22 First pump 2 4 Cleaning device 26 Second holding tank 28 Second pump

Page 12 200533429 Brief description of the diagram The first diagram is the schematic diagram of the structure of the cleaning device installed in the cleaning liquid circulation system of the present invention. The second figure is a schematic diagram of the structure when the cleaning liquid in the cleaning liquid circulation system of the present invention needs to be replaced. The third figure is a schematic diagram of the structure of a filter for cleaning by using the cleaning device of the present invention.

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Claims (1)

200533429 VI. Application patent scope 1 A filter washing device that can be extended in a cleaning liquid circulation system, which is installed in a cleaning liquid circulation system, and the life of the circulation system package is clear. The cleaning liquid contains a cleaning liquid. The first accommodating tank is connected with a heater and a filter to make the cleaning solution. The filter and the filter are equipped with a first control accommodating hydrochloric acid, which is mixed in the cleaning valve control 2 4 a second circuit. If the application liquid system is 1) ° If the application device is metal, such as application valve opening control. For example, if you apply for a tank pump, the patented flow of hydrogen and oxygen will filter out the organic patent. The patented patented patented patented patented patented patented patent may be used to remove impurities, valves, the tank, and the liquid. The liquid circulation is the cleaning liquid. The flow range is first changed, and the cleaning is performed in the cleaning and washing device, which includes the two controls equipped with a second containing tank system and the mixed liquid second containing tank as described in the filter item. Clean the hydrogen oxide and the super device, and use the liquid to pass through the hydrofluoric acid at the two ends of the heater, and use the pipeline valve to flow or not to the mixing device. The pure water is mixed. The first pump heats up and controls each hydrogen oxide on the pipeline and the connection installation uses the control; and the cleaning liquid (SC-range cleaning device described in item 1 of the scope) in the tube, wherein the impurities in the cleaning liquid are filtered , Including silicon, silicon dioxide, matter, dust, etc. The cleaning device described in item 1 of the scope, wherein the control uses one of an automatic timer and a manual method to scope the cleaning device described in item 1, wherein the Second the Engaging in a hydrofluoric acid solution is dilute hydrofluoric acid, Page 14 200533429 VI. Scope of patent application The dilution ratio of hydrofluoric acid and water is between 1 ·· 10 to 1 · · 1 0 0 0 6 · The cleaning device described in item 1 of the scope of patent application Among them, hydrofluoric acid, hydrogen peroxide and hydrochloric acid in the mixed liquid are all semiconductor-grade ones. 7. The cleaning device according to item 1 of the scope of patent application, wherein the second pump is a pump capable of resisting the hydrofluoric acid, hydrogen peroxide and hydrochloric acid. 8 · The cleaning device according to item 1 of the scope of the patent application, wherein the material of the pipeline is selected from the group consisting of polyvinylidene fluoride (PVDF), perfluorooxyethylene ether (PFA), and polyetheretherketone (PEEK). One of them. 9 · The cleaning device described in item 1 of the patent scope, wherein when cleaning the circulation system, the cleaning liquid in the first storage tank is first discharged, and ultrapure water is installed in the first storage Inside the tank, a first pump is used to flow the ultrapure water in the pipeline to clean the entire circulation system. 10. The cleaning device according to item 1 of the scope of patent application, wherein when cleaning the filter, the first pump is first turned off and the second pump is started, so that the mixed liquid in the second holding tank is in the Clean the filter by flowing in the pipeline 0 Page 15