TW200407420A - Aqueous cleaning composition for post chemical mechanical planarization - Google Patents

Abstract

The invention relates to an aqueous cleaning composition for post chemical mechanical planarization, comprising 0.1 to 10 wt% of a quaternary ammonium salt or an alcohol amine or a mixture thereof, and water. The aqueous cleaning composition of the present invention has a low surface tension, provides wafers with a good wetting effect, and is able to effectively remove residual contaminants from the surfaces of the wafers obtained from a copper processing and treated by chemical mechanical planarization. Furthermore, the aqueous cleaning composition of the invention can be prepared in the form of a highly concentrated liquid so as to efficiently save the freight and be conveniently transported and stored.

Description

200407420 A7 __ B7 V. Description of the Invention (彳) Field of the Invention The present invention relates to a cleaning composition with a specific chemical composition in a semiconductor back-end process, which effectively removes silicon wafer surface contaminants after chemical mechanical planarization in a copper process. To facilitate the subsequent thin film deposition, lithography and other processes. BACKGROUND OF THE INVENTION During the chemical mechanical polishing (CMP) polishing process, a large amount of fine abrasive particles and chemical aids' in the polishing solution and the peeling debris during the polishing process may adhere to the wafer surface. Generally, the common contaminants after wafer grinding are metal ions, organic compounds, or abrasive particles. If there is no effective cleaning procedure to remove the above contaminants, it will affect subsequent processes and reduce the yield and reliability of components. Therefore, the cleaning process after CMP polishing has become a key technology for the successful application of CMP in semiconductor processes. U.S. Patent No. 6,044,851 discloses a post-CMP cleaning composition containing tetraalkylammonium fluoride. U.S. Patent No. 6,030,932 also discloses a post-CMP cleaning composition of a fluorine-containing compound. However, their wastewater containing self-cleaning cleaning composition is not easy to treat and easily causes environmental pollution. Recently, wafer cleaning steps after chemical mechanical planarization are mostly performed using a wafer cleaning machine including a polyvinyl alcohol (PVA) brush, which directly contacts the wafer surface with a PVA brush head, brushes away dust on the wafer surface, and etches the wafer surface. Then, ‘megahertz’ megasonic cleaning technology is used to shake out the cleaning. Finally, the surface of the wafer is micro-etched with chemicals such as acid solutions, and the dissolution characteristics are -4. This paper is in accordance with the Chinese National Standard (CNS) A4 (210 X 297 mm) 200407420 A7 B7 V. Explanation of the pollution (2) To remove surface contamination. Today's semiconductor devices have been developed towards smaller line widths and higher volume densities. When the minimum line width of integrated circuits is reduced below 0.25 microns, the time delay caused by the resistance of the metal wire itself and the parasitic capacitance of the dielectric layer (RC delay) has become the main key that affects the speed of component operations. Therefore, in order to increase the computing speed of the components, the semiconductor industry currently adopts low a 黾 dielectric materials (low κ dielectrics), and the use of copper metal wires to replace the traditional copper alloy wires, in order to improve the conductive speed of integrated circuits and The computing speed of the component. The representative low-dielectric constant materials that are often discussed at present are shown in Table 1.The surface of these materials is mostly hydrophobic. As a result, aqueous cleaning compositions often cannot effectively wet the surface of the material, and therefore cannot be combined with the surface of the material. Effective contact and action of pollutants. Therefore, it is still necessary to find a cleaning solution that can effectively wet and clean the surface of a low dielectric constant material. Table 1: Basic physical properties of representative low-k dielectric materials

Contaminants on wafer surface after chemical mechanical planarization treatment1. The surface tension of the cleaning composition of the present invention is low

SiLK (Note) Even porous SiLK amorphous phase ratified carbon ______ film siliconized, especially hydrophobic on the wafer

This paper size applies to Chinese National Standard (CNS) A 200407420 at ------------- B7 V. Description of the invention (3) The material (such as the dielectric material with low '1 private hanging number) has good Wetting effect This good wettability enables the cleaning liquid to effectively contact and function with the wafer, so it can improve the cleaning effect; 2 · The cleaning composition of the present invention does not contain a combination of a a serious cause of steel, low dielectric materials and various materials on the wafer Corrosive H ^ Α Α ^ ^ chemical substances such as liceic acid, hydrochloric acid, sulfuric acid and ammonia; and 3. The cleaning composition of the present invention does not contain nan m, ^. A ^ σI and jujube ring, and its The metal content is less than 1 PPm, so its waste has little impact on the environment. OBJECT AND SUMMARY OF THE INVENTION The purpose of the present invention is to provide an aqueous cleaning composition for post-chemical mechanical planarization, the main component of which is a quaternary ammonium salt or an alcohol amine or a mixture thereof, and the terminal or branched polymer Non-ionic surfactant of oxyethylene alcohol and water 0 Brief description of the diagram Figure 1: Comparison of the wetting effect of water and the composition of the present invention on a low dielectric constant material. Detailed description of the invention The present invention relates to an aqueous cleaning composition for post-chemical mechanical planarization, which comprises from 0.1 to 10% by weight of a quaternary ammonium salt or alcohol amine or a mixture thereof, from 0.0001 to 0.2% by weight of a terminal or Polyoxyethylene alcohol nonionic surfactant with branched chain containing [_ (〇 (3j * j2CH2) n0HJ functional group and water. The cleaning composition of the present invention can be adjusted by adding an alkali such as KOH { The value of 11 is between 7 and 14, preferably between 9 and 1 2.5. The quaternary ammonium salt used in the present invention is not particularly limited. It is a familiar one. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 200407420 A7 B7. 5. Description of the invention (4) This Known by those skilled in the art. The quaternary ammonium salt that can be used in the present invention can be selected from tetramethyl ammonium hydroxide (teUamethyl ammonium hydroxide), tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide, for example (TPAH, tetraproplyammonium hydroxide) or tetrabutyl ammonium hydroxide (TBAH), or a mixture of two or more of these quaternary ammonium salts. The alcohol amine used in the present invention is not particularly limited, and it is also well known to those skilled in the art. U.S. Patent No. 6,1 94,366 discloses the types of alcohol amines that can be used in post-MP cleaning compositions, the contents of which are incorporated herein by reference. Therefore, the alcohol amine that can be used in the present invention may be selected from, for example, ethanolamine, diethanolamine, triethanolamine, triethanolamine, 3-arnino-b propanol, and methyiethan. iamine), and methyldiethanolamine, or a mixture of two or more of these alcoholamines. The quaternary ammonium salt or alcohol amine or a mixture thereof used in the present invention is used in an amount of 0.1 to 10% by weight, preferably 0.1 to 5% by weight. The non-ionic surfactant containing terminal (OCf ^ cHJnOH) polyoxyacetic alcohol used in the present invention is preferably one having the structure of the following formula (I). R2 R3 R1-CC = CC- R4 I As (〇CH2CH2) n〇HR / τ,

200407420 A7 B7 V. Description of the invention (, where 'n is a value from 1 to 30'1, 12, Han 3, and 114 are each hydrogen or a hydrogen radical, and R5 is hydrogen or Ci_c6 alkyl or _, 2CH2) m. H 'where m is a value from 1 to 30. Non-ionic surfactants that can be used in the present invention are commercially available, such as Surfynoi series surfactants manufactured by Air Products. According to the 4-preferred embodiment of the present invention, the non-ionic surfactant of the formula ⑴ used in the present invention may be wherein r2 and r3 are methyl groups; Rm is isobutyl '; JL R5 is _ (〇CH2 (: H2) mC> H. The content of the non-ionic surfactant in the cleaning composition of the present invention is 0.001 to 0.2% by weight, and preferably 0.0001 to 0.001% by weight. The cleaning of the present invention The composition may optionally include additives known to those skilled in the art that can be used in post-mechanical planarization cleaning compositions. Such additives include agents such as organic acids having chelating ability to metals, and preferably organic acids. It is selected from malonic acid, glutaric acid, adipic acid, oxalic acid, stick-like acid, rhymonic acid, or tartaric acid or a mixture of two or more of the above acids. When present, the content of the organic acid is G · 1 to 15 % By weight, preferably G.mo% by weight. Other additives used as needed include, for example, polyhydric alcohol compounds and inhibitors. The preferred polyhydric alcohol compounds are selected from ethylene glycol, H propylene glycol, butanediol or Diethylene glycOi, or two or more of these The mixture of alcohols, when present, is used in an amount of up to 5% by weight based on the total weight of the composition. A preferred corrosion inhibitor is a triazole compound, more preferably a benzotriazole (benz. uiaz〇ie BTA) and / or its derivatives, when present in the cleaning composition of the present invention, the amount of the corrosion inhibitor is from 0.001 to 5% by weight based on the total weight of the composition. SS Home Standard (CNS) A4 Specification (210 X 297 ^ 17 200407420 A7

The cleaning composition of the present invention can be concentrated into a high-concentration liquid, so that it has low freight costs and improves storage stability. Depending on the concentration of the group after concentration, the concentration of the quaternary ammonium salt or alcohol amine or its mixture may be from 2 to 40% by weight, and the concentration of the surfactant may be from 0.001 to $ weight, ❶ // 3 The following examples will further illustrate the present invention, but not for the scope of the present invention. Anyone familiar with the art can easily achieve decoration and changes, which are all included in the scope of the present invention. <仏 Example: Wetting effect test of various surfactants: Commercially available glycols, cationic, anionic, and non-ionic interfaces were added to deionized water at 500 ppm, and the surface tension and Contact angle to SiLK and Silicon Carbide (SiC). The results obtained are shown in Table 2 below. 200407420 A7 B7 Table 2 Example No. Surfactant Source Surfactant Type Surface Tension (Dyne / cm) Contact Angle of Solution to SiLK Material Contact Angle of Solution to Silicon Carbide Material 1 Deionized Water 74.0 82.8. 75.7 ° 2 500ppm glycol glycol aqueous solution 73.5 * 79.7 ° 80.9 ° 3 500ppm PEG200 aqueous glycol 74.1 79.6 ° 76.Γ 4 500ppm KC-143 aqueous solution is cationic 61.9 68.7 ° 72.4 ° 5 500ppm 12 Burning surface sulfuric acid is (C12H25OS〇3 (NH4) aqueous solution anionic 50.7 81.5 ° 74.7 ° 6 5 OOppm surfynol 440 aqueous solution AIR Produ cts nonionic 35.4 40.5 ° 52.9. 7 5OOppm surfynol 336 aqueous solution AIR Produ cts nonionic 28.8 37.4. 48.8 ° II. 5. Description of the invention (a) From the data of Examples 2 and 3 in Table 2, it can be seen that glycols and polyglycols cannot effectively reduce surface tension and wet SiLK and silicon carbide surfaces; (b) From examples It can be seen that cationic and anionic surfactants (KC-143 and ammonium dodecyl sulfate) can reduce the surface tension but cannot completely wet the surface of SiLK and silicon carbide; and (c) From Example 6, It can be seen that non-ionic surfactants (surfy η ο 1 440 and surfynol 3 3 6) can effectively reduce the surface tension and wet the surface of SiLK and silicon carbide. (D) As shown in Figure 1, water and 5% Ethanolamine + 500ppm surfynol -10- This paper size applies to Chinese National Standard (CNS) A4 (210x 297 mm) 200407420 A7 B7 V. Description of the invention (8 3 3 6 aqueous solution is poured on the surface of SiLK, it can be seen that the latter can completely wet its surface. Charm 8-15 Aqueous cleaning composition preparation: Add different kinds and proportions of quaternary ammonium salts or alcohol amines and surfactants of different types and proportions as shown in Table 3 to the water and stir, and add K 〇η to adjust the resulting cleaning if necessary. Ρ value of the liquid. Evaluation of cleaning effect: (1) Take a commercially available copper process grinding liquid ETERPOL-U6 and hydrogen peroxide in a 9: 1 mixture, and add 7 2 ppm copper nitrate to prepare a contaminated liquid. (2) Immerse a wafer with a low dielectric constant material Si LK or silicon carbide on the surface for 12 minutes, then immerse it in deionized water for 2 to 3 seconds, and then take it out. (3) Place the contaminated wafer in a cleaning machine. (4) Measure the number of surface particles with a surface defect measuring instrument (KLA-2138). (5) Calculate the removal rate, where the removal rate is the number of particles before cleaning. Number of particles after) / Number of particles before cleaning X 100%. The results obtained are shown in Table 3. -11-This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210X297 mm) 200407420 A7 B7 V. Description of the invention (Table 3 Composition of cleaning solution and cleaning effect Fu

SiLK surface residual particle removal rate wt% tetramethylammonium hydroxide aqueous solution 13.6 35% 38 ° / 〇10 11 12 13 15 5 wt% ethanolamine aqueous solution --------- 5 wt% tetramethylammonium hydroxide aqueous solution — 500ppm surfynol 440 ------- 5 weight 1% ethanolamine + 500 ppm surfynol 440 aqueous solution 5 weight f% diethanolamine + 500ppm surfynol 440 aqueous solution 5 weight 1 *% diethanolamine + 500 ppm surfynol 336 aqueous solution 5 weight% Ethanolamine + 500ppm surfynol 336 aqueous solution, adjust pH with 1N KOH 5 wt% Ethanolamine + 500ppm surfynol 336 aqueous solution, adjust with ιΝΝΝ〇3? 1 ^ value 5% by weight ethanolamine + 0.5% by weight oxalic acid 500ppm surfynol 440 aqueous solution, 12.3 13.6 12.3 11.7 11.9 26% 77% 72% 68% 70% 72%: 77% 28% 78% 73% 71% 74% 70 ° / 〇

82% i) From the data shown in Table 3, it can be known from Example 8 and 9 that the four-stage use of salt or alcohol amine alone has no obvious cleaning effect. ii) From Examples 8 and 10 and 9 and 11, it can be compared that aw π flat heart and surfactant can improve the cleaning effect. -12- 200407420 A7

iii) iv) v) Tianbei wiu master i 3 Keshanshan π ”There are different kinds of quaternary ammonium salts or alcohol amines and surfactants mixed with the cleaning effect of Example 1 1, 14, 4 and 1 si See the cleaning effect under different pH values. From the examples 1 1 and 16 can be compared μ 4 Ershan — τ, the addition of oxalic acid can slightly improve the cleaning effect. 0 The following patent scope is used to define the reasonable protection scope of the present invention. It should be understood that the improvements made by the skilled person based on the various members that can be achieved by the disclosure of the present invention should also belong to the reasonable protection scope of the present invention. -13- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm)

Claims (1)

200407420 Hei Fanli specially invited AB c D for water-based cleaning composition after chemical mechanical planarization, which contains: '(a) 0.1 to 10% by weight of a quaternary ammonium salt or an alcohol amine or a mixture thereof (B) 0.000 1 to 0.2% by weight of a non-ionic surfactant containing terminal or branched polyoxyethylene alcohol [· (〇CH2CH2) nOH] (wherein the value of i to 30); and U) water. 2. The composition according to item 丨 of the patent application range, wherein the composition has a pH value between 7 and 14. 3. The composition according to item 1 of the patent application range, wherein the composition has a pH value between 9 and 12.5. 4. The composition according to item 1 of the scope of patent application, wherein the quaternary ammonium salt is selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide, Or a mixture of two or more of these quaternary amines. 5. The product according to item 1 of the scope of the patent application, wherein the alcohol amine is selected from ethanolamine, diethanolamine, triethanolamine, propanolamine, methylethanolamine or methyldiethanolamine, or two or more of these alcohols A mixture of amines. 6. The composition according to item 1 of the scope of patent application, wherein the amount of the quaternary ammonium salt or alcohol amine or mixture thereof is from 0.1 to 5% by weight. 7. The composition according to item 1 of the scope of patent application, wherein the non-ionic surfactant containing polyoxyethylene alcohol at the end or branch is a non-ionic surfactant selected from the structure of the following formula (): 14- The size of this paper is suitable for CNS A4 specifications (21GX 297 public directors) &quot; — ~ —___ 200407420 A8 B8 C8 __________________, the scope of patent application R2 R3 R1—rod—C three C one C—R4 (I) where η is a value from 1 to 30; R1,! ^ 2 ,! ^ 3 and R4 are each gas or fluorenyl; and R5 is hydrogen or Ci-Cs alkyl or-(〇CH2CH2) mOH, where m is a value from 1 to 30 ^ 8 as the composition of the scope of the first patent application And other organic acids having chelating ability. 9. The composition according to item 8 of the application, wherein the organic acid is selected from the group consisting of malonic acid, glutaric acid, adipic acid, oxalic acid, citric acid, malic acid or tartaric acid, or a mixture of two or more of the foregoing acids. 10. The composition according to item 8 of the application, wherein the organic acid is used in an amount of 0.1 to 10% by weight. 11. The composition according to item 1 of the patent application scope, further comprising a polyhydric alcohol compound. 12. The composition according to item 11 of the scope of patent application, wherein the polyhydric alcohol compound is selected from the group consisting of ethylene glycol, 1,3-propylene glycol, butanediol, diethylene glycol (diethylene glycol), or two or more A mixture of these alcohol compounds. 13. The composition according to item 11 of the scope of patent application, wherein the amount of the polyhydric alcohol compound is 0.1 to 5% by weight. 14 · If the composition of the scope of application for the item 1 of the patent, in addition contains a corrosion inhibitor 0 -15- This paper size applies the Chinese National Standard (CNS) A4 specification (21 × 297 mm) 200407420 A8 B8 C8 15. If the composition of the scope of the application for the patent item No. 14 'wherein the corrosion-inhibiting sword is a triazole compound 〇16. For the composition of the scope of the patent application No. 15 where the triolized character is benzene And Sansa and / or its derivatives. 17. The composition according to item 14 of the patent, wherein the amount of the corrosion inhibitor is 0.001 to 0.5% by weight. 18. If the composition of any of claims 1 to 17 of the scope of patent application, it can be reduced to a concentrated cleaning solution in the south. 19. The composition according to item 18 of the scope of patent application, wherein the highly concentrated cleaning solution contains (a) 15 to 40% by weight of a quaternary ammonium salt or an alcohol amine or a mixture thereof; (b) 0.001 to 2% by weight % Non-ionic surfactant; and (c) water. Order -16- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) Application Date No. 091132581 Class 〇 / (P Vd ^ (The above columns are filled out by the Bureau) A4 C4 200407420 Chinese Manual Replacement Page (January 1992) f | Patent Specification-, Cloud S Name Chinese Water-based Cleaning Composition after Chemical Mechanical Flattening Pod AQUEOUS CLEANING COMPOSITION FOR POST CHEMICAL MECHANICAL PLANARIZATION Bo Zongwen Jian Yang Li Liu Chen 1.2.3.4. First Name ~~~ Names BO-MIN YANG and TSUNG-HO LEE Zheng WEN-CHENG LIU JEAN CHING CHEN Nationality ROC 1. ROC 1. No. 23, CHINGJUNG ST., 700, Taichung Street, Tainan City JUNG CHIU, TAINAN CITY, TAIWAN, ROC 2. No. 12, DAPINGRD. UGANGSHIANG, PINGTUNGCOUNIY, TAIWAN, RO.C. 3. Dayi Road, Zhongli Village, Linyuan Township, Kaohsiung County Lane 12, NO. 12, LANE 37, DAYIRD., LINYUAN SHIANG, KAOHSIUNG COUNTY, TAIWAN, ROC 4. Tainan City 701, Dongmen Road, Section 308, Lane 137, No. 137, 10th Floor, 12 10FL.-12, NO. 137, LANE 308 , SEC. 3, DUNGMEN RD., DUNG CHIU, TAIN AN CITY, TAIWAN, R.O.C. national applicants Changxing Chemical Industry Co., Ltd. ETERNAL CHEMICAL CO., LTD. ROC, Republic of China ROC, No. 578, Jianong Road, Sanmin District, Kaohsiung City 578? CHIEN KUNG RD, KAOHSIUNG, TAIWAN, ROC Operating specifications (⑽ x 297 公 董)