TW460611B - Process for cleaning showerhead for a chemical vapor deposition chamber - Google Patents

Abstract

The present invention provides a process for cleaning a showerhead for a chemical vapor deposition chamber. First, the showerhead is dipped into an alkaline reagent containing ammonium water so as to remove aluminum fluoride attached on the showerhead. Subsequently, the residual alkaline reagent remaining on the showerhead is removed. The showerhead is made of an aluminum-containing component, and the aluminum fluoride is obtained from the reaction of a plasma of a fluorine-containing gas used for cleaning the chamber and aluminum. By using the ammonia water-containing alkaline reagent, the showerhead for a chemical vapor deposition chamber can be effectively cleaned. Thus, the process stability can be increased and the life span of the showerhead can be lengthened.

Description

4606 1 1 V. Description of the invention (1) The present invention relates to a method for cleaning a gas distributor of a chemical vapor deposition reaction chamber, and particularly to the use of an alkaline agent containing ammonia to remove fluorine attached to the gas distributor. How to clean aluminum. In the manufacture of integrated circuits, silicon oxide is usually used as the dielectric layer between the metal wires, mainly due to its small dielectric constant and good thermal conductivity. Since the metal wire is made of aluminum metal or alloy, and its melting point is less than 500 ° C, the deposition temperature of the silicon oxide dielectric layer needs to be limited to below 450 ° C. At present, the silicon oxide process used for depositing metal layers is mainly zonezone 08 0800 and 1 (16 (ozone-tetraethylsilicic acid (seven 61 ^ & 61: 11〇 乂 78 114 & seven 6) oxide) 'ΡΕ-Oxide (plasma-enhanced oxide) etc. As the wafer area becomes larger, the reaction chamber of a single wafer is becoming more and more popular due to its many advantages. The common operation flow of this single reaction chamber For Ozone catalysis or plasma to promote deposition and use in-situ plasma method to remove oxidized stones in the reaction chamber alternately. In the wafer reaction chamber, the gas flow is evenly distributed and in a single,-) ·, ν * Muscle Jade! • ^ Knife Recognition-% artificial gas dispenser (showerhead). Material of gas distributor = Ming Jin needs to be anodized due to the process or has a surface. When the reaction is reversed, the method is to clean the oxidized stone in the reaction chamber, and the original fluoride is used. The reaction mechanism is that fluorine is generated under the action of plasma. The fluorinated silicon compound is pumped to clean the oxidized stone. The distributor is large, with the aid of plasma, it ’s easy to interact with oxygen gas mouth or vaporize aluminum to produce high boiling aluminum fluoride.

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Focusing on the surface of the gas distributor and the holes for the gas to enter the reaction chamber, the subsequent changes in the deposition rate, stress, and etch rate of the silicon oxide film are deposited, making it difficult to maintain the stability of the process. Shortening 'and high frequency preventive maintenance (PM; preventive ^ maintenance) will be unavoidable. Therefore, it is necessary to clean the gas distributor regularly. The current method of cleaning gas distributors only uses D.〗. Water (deionized water) plus ultrasonic vibration and drying. Because this method cannot effectively remove the attachments of fluoride, it gradually accumulates, resulting in a change in the plasma and gas flow patterns. It increases the frequency of parameter adjustment and shortens the life of the gas distributor.

Therefore, 'the purpose of the present invention is to provide a method for cleaning a gas distributor of a chemical vapor deposition reaction chamber, which can clean the aluminum fluoride attached to the gas distributor' in order to solve the above problems, to increase process stability and prolong, The life of the distributor 'is free of metal contamination. ^ Achieving the Purpose of the Invention 'The present invention provides a method for cleaning a gas distributor of a chemical vapor deposition reaction chamber, including the following steps: (a) immersing the gas distributor in an alkaline agent containing ammonia to remove Aluminum fluoride attached to the gas distributor; and (b) removing residual alkali remaining on the gas distributor.

The gas distributor is made of an aluminum-containing component, and the above-mentioned fluorination inscription is obtained by reacting a fluorine-containing plasma cleaning gas used to clean the reaction chamber with aluminum. 'As mentioned before, when cleaning the CVD reaction chamber using a fluorine-containing plasma to clean the gas' and the gas distributor in the reaction chamber is made of aluminum-containing components, the I-poly cleaning gas will be mixed with the aluminum of the gas distributor. Effect 'Generates Gao Xiangdian

Page 5 4 606 1 1 V. Description of the invention (3) The surface of the distributor and the basicity of the water that feeds the gas into the reaction chamber is more alkaline than ammonia. The distributor of fluorine reaction chamber is preferably fluorine 'aluminum hexafluoride. The cleaning gas is made of aluminum fluoride. 'Reaction with water removal fluid and fluorinated scrubbing gas distributor table reaction' to produce soluble, with the apparatus of the present invention, the process such as nitrogen trifluoride can be increased. Gas Dispensers Novel Method. Among the first potions, the most potent ones are water-removing potions. The removal of hydrogen peroxide helps to cause the organic pollution caused by the following reactions: Pharmacy to clear and aluminum fluoride. Therefore, the gas distribution life. Compounds, such as two carbon (c2F6). The basicity of the water in the dispenser. This solution containing ammonia is possible. Fluorinated aluminum, which can be processed by aluminum, is stuck in the holes of the gas. The present invention uses aluminum fluoride attached to the ammonia surface. Because of the product of water, it can be used to clean the chemical vapor deposition stability. It can also extend the gas containing I electric cleaning gas (nf3), carbon tetrafluoride ( cf4) The invention can provide a method for immersion, alloying, or oxygen. First, the gas distributor is immersed in the gas distributor. The adhesion of the gas distributor includes ammonia and hydrogen peroxide, and the dyeing can be performed. The ammonium fluoride and aluminum hydroxide obtained from the reaction of the alkaline medicine 3NH4OH + AIF2 —i ^-^ 3NH4F + Al (〇H) 3 containing ammonia are soluble in water. Therefore, after soaking in the alkaline medicine, As long as the residual alkali remaining on the gas distributor is removed, ammonium fluoride and aluminum hydroxide can be removed. Residual alkali is usually removed by flushing the gas distributor with water, which can be washed in a general quick rinse tank.

Page 6 4606 1 1 V. Description of the invention (4) 'I " In order to achieve a better effect, after removing the residual alkali, it is better to immerse the gas in the acidic medicament, then remove the residual acid remaining on the gas distributor, and finally dry the gas distributor. —The main purpose of immersion in acidic medicament is to remove the aluminum-ammonia compound film formed on the surface of the gas distributor after immersion in water at the previous stage, and also to remove metal pollution that may occur during operation. Similarly, to remove residual acid, the gas distributor can usually be flushed with water. Rinsing with water can help remove man-made contamination such as sodium and potassium. The drying method can use natural shade drying 'or heat and dry in the oven. In addition to the method for removing residual inspection or residual acid, in addition to the direct water flushing method, the gas distributor can be immersed in water and oscillated with ultrasonic waves to achieve better results. According to the present invention, in the alkaline medicine containing ammonia, the volume mixing ratio of ammonia, hydrogen peroxide, and water may be i ~ 5: Bu 5: 5 ~ 丨 〇, and the preferred mixing ratio is 2 ~ 3: 3 ~ 5. : 7 ~ 9. Generally, the concentration of ammonia is 29%, and the concentration of hydrogen peroxide is 100% by weight. The time and temperature of the body dispenser immersed in the alkaline medicine containing ammonia is not limited. The preferred time may be 40 minutes to 1 hour, and the preferred temperature may be 20 ° C ~ 100t :, preferably 4 °. 〇c. The acidic medicament suitable for the present invention may be nitric acid, hydrochloric acid, sulfuric acid and the like. For J: the concentration range can be 1M ~ 5M ', preferably 2M. Similarly, the time and temperature for immersing the gas dispenser in the acidic agent is not limited. The preferred time may be 15 to 20 minutes, and the preferred temperature may be 20 t.

Page 7 46061Ί V. Description of the invention (5) 100 0 ° C. In the following, several examples are given to explain the method, features and advantages of the present invention in more detail. It is not intended to limit the present invention. The scope of the present invention shall be subject to the scope of the attached patent application. . The chemical vapor deposition performed in the following examples was performed under the following conditions: a temperature of 400 C, a pressure of 5 Torr, an RF power of 55 watts, and a reaction gas of TE 〇s. Example 1 (Belonging to the single-wafer reaction chamber 'containing a new gas distributor), the "chemical vapor phase" method (c :) deposits 13,000 angstroms of silicon oxide film on the V silicon wafer. 〇 After the tablets, take out the gas distributor in the reactor, carry out the invention of the gas 8 (volume mixed compounds. Then remove the residual test, rinse) ° Connect the bell to remove the aluminum ammonia compound pollution. Then bubble Immerse the body dispenser in deionized example 2 in ammonia: hydrogen peroxide: water = 2 · 5: 4 ratio) alkaline agent for about 60 minutes to remove aluminum fluoride, and rinse the gas dispenser with deionized water. 5 minutes, this step is called quick down (QDR; quick down =, immersed in diluted nitric acid or hydrochloric acid (2 M) for about 5 minutes before the first paragraph of ammonia water soaked on the surface of the gas distributor knife film, but also can Clear operation process may produce

^ Minute fast undershoot. Finally, the gas is distributed and immersed in water, ultrasonic vibration is applied, and then dried. D 4 606 1 1 V. Description of the invention (6) The gas cleaned in the chamber according to the method of Example 1 was grown by chemical vapor deposition to 1000 angstroms ^ assembled back to the silicon oxide deposited by the above-mentioned inversion analysis. Metal contamination of the film. = Si ’and then show. From the analysis results in Table 1, it is known that the oxidized stone is thin and the content of impurities is much lower than that of ordinary CVD dielectrics +, and atom / cm2 of metal π dye. 疋 的 袼 1E12 Implementation Example 3 A new unused gas distributor was used to assemble a Centura-Dxz reaction chamber with-; the US commercial application deposited a silicon oxide film of about 13,000 angstroms. The film was formed on a silicon wafer by two-to-eight method. Characteristics, measured by the etching rate, silicon oxide H20 deposited with a knife, j kg = 30 .. 6: 64 (volume ratio). The results are shown in Table II. The two-liquid composition is NH4F: HF: f. Example 4 Use new unused gas

The reaction chamber of CeW-Dxz is equipped with a US company applying a silicon oxide thin layer vapor deposition method that deposits 1 3000 angstroms. The gas distributor is taken out from the silicon wafer. After washing, the washing method will be followed by washing (that is, the newly-cleared gas distributor of the present invention performs the second Λ and then deposits 300,000 tablets, and then takes the tablets, and the cleaning steps ... first, then repeats the reinstallation and deposition 3_ Regenerate, regenerate, regenerate + back to the reaction chamber in Example 1, and wash the gas distributor membrane three times to perform various thin film characteristics:; upper; 1 = °°° Angstrom cvD oxidation dream meeting Example 5 The results are shown in Table 2. 460611 V. Description of the invention (7) The steps are the same as in Example 4, but the method of cleaning the gas distributor is changed. The cleaning method in this embodiment is a conventional method. The gas distributor was immersed in deionized water, ultrasonically shaken for 30 minutes, and then dried. The gas distributor cleaned three times in this old method was reinstalled in the reaction chamber, and the growth was about 1 3000 angstroms on the wafer. The CVD silicon oxide film was analyzed for the characteristics of each film. The results are shown in Table 2. ′ From the results in Table 2 It is known that after the gas distributor is cleaned by the old cleaning method, the uniformity of the deposited CVD silicon oxide is significantly deviated, and the stress value is low. However, the gas distributor cleaned by the new cleaning method or a new gas distributor, two The characteristics of the deposited CVD silicon oxide film are equivalent. Therefore, it can be proved that the present invention can completely remove the attached aluminum fluoride compound, so that the old gas distributor can restore the quality of the new product. Example fi Use a new, unused one The gas distributor is installed in a US-based Centura-Dxz reaction chamber, and a silicon oxide film of about 1 3000 angstroms is deposited on a silicon wafer by chemical vapor deposition. The single wafer is repeatedly deposited until the number of leaves deposited on the leaf reaches 300 The film characteristics of the silicon oxide thin film deposited last time are analyzed. The results are shown in Table 3. The cumulative number of deposited sheets in Example 4 was 900,000, and the cleaning method was repeated three times in Example! The gas distributor was re-installed, and a CVD dysprosium oxide of about 13 mm was grown on the circle. A single wafer was repeatedly deposited until the cumulative number of deposited wafers reached 30,000 or 4,000. Analysis of silicon oxide film is then the best film properties after the first deposited. The results are shown in Table three

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The accumulation, v-etching in Example 5 was performed. The number of collapsed A Λ ΑΑΜΜ Y 9900 pieces was used, and Exercise 4: The gas distributor that was shoveled and Φ was re-installed again. ^ ,. Know—old, > CVD silicon oxide film with a monthly wash of 1 300 Angstroms. It is said that the number of accumulated wafers on the wafer has reached 1000. (A 'Erji Soap tablets, until the cumulative sink distributor, after depositing 1,000 tablets, said: the characteristics of the gas film cleaned by the old cleaning method is too poor, lost = = oxidized stone, oxidized stone After the thin analysis, the last deposited porphyrin = ^, so it is no longer accumulated.) Table 3 shows. The thin film characteristics of the product of oxidized stone oxide film. As a result, after the crucible has passed through the hair, in terms of the oxygen distributor, the silicon film can be cleaned by 0.3 / m cleaning method, which can only increase the length of the new silicon film. It can be known from the characteristics of the dust-washing gas that the process stabilizes the gas content. For the oxidized stone washing method that depends on the cleaning membrane, the volume distribution is still not good at the volume of 40. The item that has been cleaned by the method of the hair and the deposition of the container life 900 method The characteristics are still the characteristics of the film. After the sinking of 4,000 pieces, the amulet 'only deposits', such as the uniformity and the cleaning method of the moon, to extend the gas division. After the film is old, it is not bad. It is almost 1 000 pieces of oxygen standard, and the gas distributor of the dispenser should be cleaned. After the deposition of 400,000 pieces and the use of new products, the dust increases the quantified silicon film. . After using a single wafer, the oxygen level is low. Gas distributor, the number of irregular maintenance, although the present invention has been better to I5B ^, only dead * example is disclosed as above, lack of basin 廿 non-ra, uggs, according to the present invention, anyone familiar with this 蓺 ..... .It is not used to sacrifice and guilty confines when you can make changes to the fish sculpture + the essence of Zhiyue ^ retouching so the scope of protection of the present invention

4606 1 1 V. Description of the invention (9) Subject to the scope of the appended patent application. Table 1. Analysis of the contamination of tritium in the thin film of the diffuser treated with the new cleaning method of the present invention. Analysis of the elemental contamination in the thin film. Analysis element A1 Na Fe Cu Cr Ni (atom / cm2) (atcni / cm2) (atom / cm2) (atom / cm ^ (atom / cm ^ (atom / cm ^)) 2E10 4E9 4E9 2E9 4E8 7E9 Sample 1 NDND 7E10 4.7E9 2E2 ND Sample ND 1.7E10 ND 5.4E9 NDNDND Detected (not detected)

Page 12 460611 V. Description of the invention (Table 2) Comparison of the test results of the gas distributor and the new gas forging distributor in the same reaction chamber after cleaning. Mmtn rate C ^ riin) Thick uniform ribs (dyne ^ cm2) (1000 ^ Dust ^ Man (&0.3; η) Surname engraving rate (βύ ^ ύη) New product (Example 3) 6871 1.1 -10.15E8 1.465 7 2210 New cleaning method (Reward Example 4) 6926 1.2 -12.56E8 1.463 9 2105 Old cleaning method (Example 5) 73G7 2.9 -8.04E8 1.461 0 2393 • = The calculation method of the average hook degree is [(maximum value-minimum value) / 2] x almost the average value x 100% 1111 Page 13 4606 1 1 5 Description of the invention (11) Table 3. Comparison of the test results of the gas-plated distributor and the new gas radon distributor after cleaning in the same reaction chamber. Increased flj rate (Ahiin) (%) fdvnes / cm?) (≫ 0.3μτη) (kcmn) Old cleaning method 7076 4.1 -6.80E8 1.458 12 2351 (1000 pieces) New product 6937 3.5 -8.11E8 1.460 4 2302 ( 3000 tablets) new cleaning method 7013 1.9 -10.95E8 1.463 2110 (3000 tablets) new cleaning method 7045 2.2 -10.88E8 1.463 18 2113 (4 (000 pieces) * The calculation method of uniformity is [(maximum value-minimum value) / 2] χ almost the average value x100%

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Claims (1)

Sound No. 6. Shengui Patent Model 速速 枪 # 4 · Month Revision 1. A chemical method, including degassing and j drying, using the solution, 5 ~ 10. 2. Steps 3. Steps 4. Steps 5. The test of water includes the following: the gas distributor removes the remaining gas and removes the remaining dry gas from the gas to clean the ammonia-containing water. Apply for the gas such as the application agent 2 ~ 3: 3 ~ 5: 7 ~ 9 6. Water test 5: 4: 8 As the application for pharmacological vapor deposition steps: The test of hydrogen peroxide in the reaction chamber of the gas distributor, the patent scope flushes the gas, the patent scope flushes the gas, the patent scope distributor immerses the ammonia in the patent scope, the ammonia in the patent scope, and the gas distributor in the reaction chamber. The cleaning square is soaked in an alkaline agent containing ammonia to remove aluminum fluoride; the residual test on the dispenser; the acidic agent is soaked; the residual acid on the dispenser; and it is made of aluminum-containing ingredients, as described above It is obtained by reacting the cleaning gas of aluminum fluoride fluorine-containing plasma with barium. The medicament is ammonia water, hydrogen peroxide water, the mixture with water and the volume mixing ratio of water is 1 ~ 5: 1 ~ 5: The method according to item 1, wherein Removal of residual alkalinity Orchestration. The method according to item 1, wherein the residual acid body distributor is removed. The method according to item 1, wherein the residual acid is removed, soaked in water, and oscillated with ultrasonic waves. The method according to item 1, wherein the volume mixing ratio of the ammonia-containing hydrogen peroxide and water is the method according to item 5, wherein the volume-mixing ratio of the ammonia-containing hydrogen peroxide and water is 2. 0492-4407TW Rev.ll.ptc Page 16 4 β Ο 6 1 1 ___Case No. 88108628_Year Month Day__ VI. Application for Patent Scope 7. The method described in item 1 of the scope of patent application, wherein the gas is distributed The device is immersed in the alkaline medicine containing ammonia for a time of 40 minutes to 1 hour. 8. The method according to item 1 of the scope of patent application, wherein the temperature of the gas distributor soaked in the alkaline agent containing ammonia is 0 ° C ~ 100 ° C. 9. The method according to item 1 of the scope of patent application, wherein the acidic agent is selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid. 10. The method according to item 9 of the scope of patent application, wherein the concentration of the acidic drug is 1M to 5M. 11. The method according to item 1 of the scope of patent application, wherein the acid dispenser is immersed in the acidic agent for 15 to 20 minutes. 1 2. The method according to item 1 of the scope of patent application, wherein the temperature of the gas distributor soaked in the acidic agent is 20 ° C ~ 100 ° C. 0492-4407na ll.pt c page 17 .. 輋 丨 产 月 β B # ^; £ 8ΐΰ862ΐ Invention Patent Specification Petrology Vapor Deposition Chamber Fraction Si H Name of Inventor Chinese and English $ [ocess for Cleaning Showerhead for a Chemical Vapor Deposition Chamber Yin Ming (Chinese) 1. Yang Nenghui 2. Shi Honglin} Zhu Zanxi 4. Ruan Zhongjie ___— Anonymous (English) Office: Chu 3. TC Chu _4. CC Juan ---- National Republic of China 2. Republic of China 3. Republic of China 4. China Republic of China ______ — Residence and residence order — 5th floor, No. 2, Lane W, Section 1, Guangfu Road, Jinshanli, No. 22-11 Xinnan Village, Shebei Road, Gaoshu Township, Yeye County 5. # 5 市 文 华里 14 Neighborhood 田 美No. 1, Lane 6, Lane 22, Sanjie ^ ^ One of the six members of Fuer Erlayi, Lingya District, Yuxiong County ______ Dream Name ---- Desan Applicant I. Residence (Office) 1. Willow Bamboo Science JL · Quansan Road No.4 Representative Name (Chinese) Page 1 2001.04.17.001->v;, Sound No. 6. Shengui Patent Model 速速 枪 # 4 · Month Revision 1. A chemical method, including degassing and j drying, using the solution, 5 ~ 10. 2. Steps 3. Steps 4. Steps 5. The test of water includes the following: the gas distributor removes the remaining gas and removes the remaining dry gas from the gas to clean the ammonia-containing water. Apply for the gas such as the application agent 2 ~ 3: 3 ~ 5: 7 ~ 9 6. Water test 5: 4: 8 As the application for pharmacological vapor deposition steps: The test of hydrogen peroxide in the reaction chamber of the gas distributor, the patent scope flushes the gas, the patent scope flushes the gas, the patent scope distributor immerses the ammonia in the patent scope, the ammonia in the patent scope, and the gas distributor in the reaction chamber. The cleaning square is soaked in an alkaline agent containing ammonia to remove aluminum fluoride; the residual test on the dispenser; the acidic agent is soaked; the residual acid on the dispenser; and it is made of aluminum-containing ingredients, as described above It is obtained by reacting the cleaning gas of aluminum fluoride fluorine-containing plasma with barium. The medicament is ammonia water, hydrogen peroxide water, the mixture with water and the volume mixing ratio of water is 1 ~ 5: 1 ~ 5: The method according to item 1, wherein Removal of residual alkalinity Orchestration. The method according to item 1, wherein the residual acid body distributor is removed. The method according to item 1, wherein the residual acid is removed, soaked in water, and oscillated with ultrasonic waves. The method according to item 1, wherein the volume mixing ratio of the ammonia-containing hydrogen peroxide and water is the method according to item 5, wherein the volume-mixing ratio of the ammonia-containing hydrogen peroxide and water is 2. 0492-4407TW Repair ll.ptc Page 16