TW514661B - Chemical-mechanical abrasive composition for use in semiconductor processing - Google Patents

Abstract

A chemical-mechanical abrasive composition for use in polishing metal films in a semiconductor processing, which composition comprises 1-25% by weight of an abrasive particle, 1-10% by weight of an oxidant, and 0.1-20% by weight of a buffer agent for use as an abrasion enhancer, wherein the buffer agent comprises a persulfate group-containing compound or an iron (III) salt and a carboxy group- or an amido group-containing compound.

Description

514661 A7 B7 V. Description of the Invention (1) Field of the Invention The present invention relates to a chemical mechanical polishing composition. The polishing composition of the present invention has high stability and can be effectively applied to the polishing of the surface of a semiconductor wafer. BACKGROUND OF THE INVENTION In the semiconductor industry, the polishing of the surface of semiconductor wafers is a widely used technique to improve the flatness of semiconductor wafers and dielectric layers, and to facilitate the manufacture of metal circuits. Generally speaking, the polishing method for manufacturing metal circuits is to place a semiconductor wafer on a rotating polishing platform equipped with a polishing head, and apply a polishing slurry containing abrasive particles and an oxidizing agent on the surface of the wafer to improve the grinding efficiency. U.S. Patent No. 5,225,034 discloses a chemical mechanical polishing slurry comprising AgN03, a solid abrasive substance, and an oxidant selected from the group consisting of H202, H0C1, K0C1, KMg04, or CH3COOOH. This polishing slurry is used to polish copper layers on semiconductor wafers to make copper wires on wafers. U.S. Patent No. 5,209,816 discloses a method for polishing a metal layer containing A1 or Ti using a chemical mechanical polishing slurry. The polishing slurry contains about 0.1-20% by volume of H3P04 and about 1-30 in addition to solid abrasives. H2o2 by volume 〇 Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page) US Patent No. 4,959,113 relates to a method for polishing metal surfaces by using aqueous abrasive compositions . The aqueous abrasive composition includes water, abrasives (such as Ce02, Al2O3, Zr02, Ti02, Si02, SiC, Sn02, and TiC), and a salt containing the periodic table IIA, IIIA, IVA, or IVB. Group of metal cations and anions of chloride, bromide, ion, nitrate, sulfate, phosphate or perchlorate. This U.S. patent also states that the paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 514661 A7 B7 V. Description of the invention (2) Use hydrochloric acid, nitric acid, phosphoric acid or sulfuric acid to grind it in water The composition is formulated to pH = 1-6. U.S. Patent No. 5,391,258 discloses a polishing composition for polishing a composite containing silicon, silica or silicate, which contains abrasive particles in addition to abrasive particles. Hydrogen oxide and S potassium hydrogen phthalate. U.S. Patent No. 5,114,437 relates to a polishing composition for polishing an aluminum substrate, which comprises an alumina polishing agent having an average particle size of 0.2 to 5 μm, and is selected from chromium (III) nitrate and lanthanum nitrate. Polishing accelerator for zinc (III) ammonium nitrate or neodymium nitrate. U.S. Patent No. 5,084,071 relates to a method for polishing electronic component substrates using a chemical mechanical polishing slurry. The polishing slurry used contains less than 1% by weight of alumina and abrasive particles (for example, Si02, Ce02, SiC, Si3N4 or Fe203), a transition metal chelate salt (for example, EDTA ammonium iron) as a grinding efficiency promoter, and a solvent for the salt. US Patent No. 5,480,476 discusses the effect of Ce4 + and Zr4 + cations on the polishing rate of SiO2 type abrasives. Printed by the Consumer Standards Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the notes on the back before filling this page) US Patent No. 5,366,542 discloses a polishing composition comprising alumina abrasive particles and a polyamine Chelating agents for acids (such as EDTA) or their sodium or potassium salts. This polishing composition may further comprise boehmite or an aluminum salt. U.S. Patent No. 5,340,370 discloses a slurry for chemical mechanical polishing of, for example, tungsten or tungsten nitride films, comprising a potassium cyanoferrate oxidant, an abrasive, and water for use in the film, wherein the slurry has a pH of 2 to 4 value. U.S. Patent No. 5,516,346 discloses a titanium film for chemical mechanical polishing. This paper size is applicable to the Chinese National Standard (CNS) A4 (210X297 mm). 丄 4661 Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. Α7 Β7 5. Description of the invention (3) The filling liquid 'comprises a fluorinated bell and an abrasive (such as silicon oxide) at a concentration sufficient to be incompatible with the thin film, wherein the slurry has a pH of less than 8. WO 96/16436 discloses a chemical mechanical polishing slurry comprising abrasive particles having a median diameter of less than 400 microns, an iron salt oxidant, and an aqueous surfactant suspension of propylene glycol and methyl paraben. U.S. Patent No. 5,476,606 discloses a slurry for chemical mechanical polishing of a metal layer comprising an oxidizing agent that oxidizes a metal complex (such as iron nitrate), molten alumina particles containing at least 50% γ-phase, and, for example, a polyalkane Siloxane or polyoxyalkylene are nonionic surfactant additives based on acid. The polishing slurry shown by the above-mentioned previous techniques cannot avoid _ ion or transition metal / defective staining or the use of South molecular type surfactants, except for the local polishing unevenness and coarseness of the wafer surface which is easy to blister during polishing. In addition to the increase in degree, it is also because of the poor water solubility of polymer compounds, which can easily lead to the possibility of "defective staining". In addition, although U.S. Patent No. 5,476,606 shows that the use of a low molecular weight super quinic acid to suppress the polishing rate of the oxides, thereby improving the polishing selectivity of the metal / oxides, the potential of the abrasive particles cannot be increased by the hydroxycarboxylic acid (i.e., Electrokinetic potential), so it often causes slurry instability after addition. ~ In summary, in the technology of semiconductor manufacturing, companies are still looking for chemical mechanical polishing compositions of higher quality to overcome the disadvantages faced by the aforementioned prior art polishing compositions. Brief Description of the Invention The present invention provides a method for polishing metal thin films in semiconductor manufacturing processes (please read the precautions on the back before filling this page)

-6-Printed A7 by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs -----_____ B7 __ V. Description of the Invention (4) A mechanical grinding composition containing 25% by weight of abrasive particles; and 〇1_2〇 weight % As a buffering agent for grinding accelerator, wherein the buffering agent includes compounds containing persulfate group or salts containing iron (III) and compounds containing carboxyl group or amido group. Detailed description of the invention The present invention provides a chemical mechanical polishing composition for polishing a metal film in a semiconductor manufacturing process, which comprises 25% by weight of abrasive particles, preferably 3-10 weight ° / °; and 0.1-20% by weight, It is preferably 6-15% by weight of a buffering agent which is also used as a grinding accelerator, wherein the buffering agent includes a compound containing a persulfate group or a salt containing iron (m) and a compound containing a carboxyl group or a sulfonium group. The chemical-mechanical polishing composition of the present invention may further include 10-10% by weight, and Chevron is 4-6% by weight of an oxidizing agent. According to the present invention, the abrasive particles used in the abrasive composition may be general marketers, such as s102, Al203, Zrt) 2, CeC > 2, SlC, Fe203, TiQ2,

SisN4, or a mixture thereof. These abrasive particles have the advantages of high purity, high specific surface dentistry, and narrow particle size distribution, so they are suitable for use as abrasive particles in chemical mechanical polishing compositions. The oxidizing agents that can be used in the present invention are generally commercially available, such as H202, KI〇3, KBro3, K2Cr207, K2Mn207, KMn04, HOC1, CH3COOOH, or a mixture thereof. Examples of persulfate-containing compounds according to the present invention as a buffering agent component include ΗΑ208, 8〇8, 44) 至 0, 〇2, or a mixture thereof, and == Examples of the salts containing iron (111) include potassium ferricyanide, iron (III) ammonium sulfate, iron (111) nitrate, or a mixture thereof. --_____ -7- This paper is suitable for Guancai County (―CNS) Α4 size (270 ^ 297 ^ ¾ ^ ----- (Please read the precautions on the back before filling in this page) k-shirt-order five Description of the invention (5 A7 B7 The carboxyl-containing compound that can be used in the buffer of the present invention is selected from: (1) a monocarboxyl compound of the following formula: 0

Ri-C-〇r2 where ~ is hydrogen, Cl-c6 alkyl or Ci_c6 # f 垸 group; and the heart is chlorine, ammonium ion or alkali metal ion (preferably potassium ion). Examples of such mono-I-based compounds include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, glycolic acid, and lactic acid (2) a dicarboxylic compound of the formula: 4 〇R3〇-c-R4 -c.〇r2 wherein ~ is -single bond, Cl_C6fluorenyl or Ci_Qfluorenyl; and R3 is hydrogen, ammonium ion or alkali metal ion (preferably deionized ion). Examples of this type: Endyl compounds include: oxalic acid (oxalic acid), malonic acid 'γ-1' succinic acid), glutaric acid, hydroxysuccinic acid (malic acid), tartaric acid, galactic acid, and the like Salt. (3) Dialkyl compounds, such as citric acid and its salts. Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the notes on the back before filling this page) ⑷Bismuth compounds such as glycine, sarcosine, dimethylalanine and their salts. Examples of the amino group-containing compounds that can be used as the buffering agent component of the present invention include formamide, acetamide, propylamine, N-methylformamide, N-methylacetamide, urea, methyl Urea, ethylurea, dimethylurea and diethylurea. The buffer additive used as a grinding accelerator for the H-composite of the present invention can provide the following advantages: The paper size Yan quiet-8 514661 Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (6) ⑴ Since the change of pH 値 of the grinding slurry will affect the ξ_ potential of the grinding particles, 'maintaining a stable pH 値 is extremely important for the grinding slurry. The buffer used in the present invention can provide a pH 研磨 of the grinding slurry between 15 and 85, and therefore has the function of stabilizing the pH 値 of the grinding slurry. (2) The buffer used in the present invention has excellent water solubility, so it can be easily removed without remaining on the wafer. (3) The buffering agent used in the present invention has larger molecules, which will not penetrate into the wafer and cause contamination of the wafer.缓冲 The buffering agent used in the present invention is a common chemical, which is less dangerous, so it can significantly reduce the danger to semiconductor process workers and not cause pollution to the environment. (5) The respective components of the buffering agent of the present invention are relatively less corrosive compounds. However, when these less corrosive compounds are used in combination according to the present invention, unexpectedly strong corrosiveness will be generated. Therefore, Can effectively improve the scraping rate of metal thin films. The abrasive composition of the present invention may include 'for example, water as a medium. In the preparation process, water may be used to make the grinding composition liquid, and it is preferable to use conventional deionized water. The abrasive composition of the present invention can be prepared by a conventional method. For example, you can first add the abrasive particles to water and continue to stir them with a high-shear 4 × 0 blade shear mixer until the abrasive particles are completely suspended in the water. After that, Jing added water to make the abrasive particles in the slurry reach /, <solid content. According to the present invention, the solids content of the slurry is 1 to 25 weight | 0 /,, lining / 0, preferably 3 to 10 weight%. Then import the additives as described above, Basuo Pieces &lt; High-Purity Slurry-9 This paper size applies to China National Standard (CNS) A4 specifications (210X 297 mm) (Please read the precautions on the back before filling this page )

A7 B7 5. In the description of the invention (7), for example, ammonia water is added, so that the pH of the slurry is between the required range. For example, '#When the metal film to be polished 胄 W film' 丨 Control pH 在 一 between 1 · 8-2.3 i; when the metal film to be polished is Ai film '♦ pn 値 is controlled to 3 〇-4 5 Between, preferably between; and when the metal thin film to be polished is a Cu thin film, ⑻ 値 is controlled to 5.5-9.0 ^ .1? 6.〇.τ〇 ^ Γ, 〇 the present invention (grinding composition. The preparation process of the grinding composition of the present invention can be carried out at any suitable temperature, preferably at a temperature of 20-40 t. The following examples will further illustrate the present invention, but are not intended to limit the present invention. The scope, modifications and changes that can be easily achieved by anyone skilled in the art are all included in the scope of the present invention. Example 1 In this example, the silicon dioxide produced by Degussa is used, and has the same properties: 八 a ( 1) The pH range of the 4% aqueous suspension is between 36 and 43; (2) the specific surface area is 40-130 m2 / g; and (3) the specific gravity is S0.7 g / ml. Central Ministry of Economic Affairs Printed by the Consumer Bureau of Standards Bureau ------: --- II (Please read the notes on the back before filling this page} Order

At room temperature, 5 kg of the above-mentioned silicon dioxide was added to 20 kg of deionized water, and stirring was continued with a high-shear mixer until the silicon dioxide completely floated in the water and became a slurry. Then, 20 kg of deionized water was added to dilute the slurry so that the solid content of the slurry was slightly greater than 11%. Then 5 kg of oxalic acid (oxalic acid) and 3 kg of ammonium iron sulfate (111) were added to the slurry, which quickly fell into the polymer solution. After continuing to stir for 3 hours, adjust the pH of the paddle fluid with NH4OH. -10- A7 A7 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs __ ________ B7 V. Description of the invention (8) A I is about 2.0. The slurry was filtered to prepare a chemical mechanical polishing composition ' of the present invention having a solids content of about 10%. The grinding test results of the obtained grinding compositions are shown in Table 1 below. The same preparation procedure as in Example 1 was repeated, except that the acetic acid was replaced with 15 kg of formic acid. The grinding test results of the obtained grinding composition are listed in Table 1 below.

The same preparation steps as in Example 1 were repeated, except that 5 kg of alumina (manufactured by Sumitomo Chemical Co., model AKj ^ GOOg) was used to replace silicon dioxide, and i 5 kg of citric acid was used to replace oxalic acid. The grinding test results of the obtained grinding compositions are shown in Table 1 below. The same preparation procedure as in Example 3 was repeated, except that citric acid was replaced with 15 kg of glycolic acid. The grinding test results of the obtained grinding compositions are shown in Table 1 below. The same preparation steps as in Example 1 were repeated, except that ammonium iron (III) sulfate was not added. The grinding test results of the obtained grinding compositions are shown in Table 1 below. Comparative Example 2 The same preparation steps as in Example 3 were repeated, except that ammonium iron (III) sulfate was not added. The grinding test results of the obtained grinding compositions are shown in Table 1 below. Grinding test A. Apparatus: IPEC / Westech 472 ___- 11-___ This paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) (Read the precautions on the back before filling this page)

A7 B7 V. Description of the invention (9) --- ^-: --- φ ^! (Please read the precautions on the back before filling in this page. Β Conditions: Pressure: 5psi Temperature · 25 ° C Spindle speed: 45rpm platen rotation speed · 42 rpm Pedestal type: Rodel 1C 1400 Slurry flow rate: 150 liters / minute C · g pieces · (1) W film: from Silicon Valley Microelectronics, Inc., using CVD technology at 6 0.8 micron ± 5% thin film deposited on a 2-inch silicon wafer (2) Ti film: purchased from silicon Valley Microelectronics, Inc., is designed to deposit a 0.5 micron ± 5% thin film on a 6-inch silicon wafer by CVD technology (3) TiN thin film: purchased from silicon Valley Microelectronics, Inc., which uses CVD technology to deposit 0.5 micron ± 5% on 6-inch silicon wafers. Printed rubidium oxide by the Central Consumers Bureau of the Ministry of Economic Affairs. Thin film: The silicon dioxide D · slurry thermally generated on a silicon substrate was commissioned to the National Nanometer Component Laboratory: the slurry obtained in the above example i_4 and comparative example ^ was mixed with the same volume containing 2% by weight Aqueous solution, stir evenly for 15 minutes and then test the grinding process: After that, the thickness of the film needs to be measured with a film thickness tester. The metal film is measured with a four-point probe to measure the sheet resistance of the film, and the film thickness is converted by the following formula: —________- 12-This paper size applies to Chinese national standards (CNS) A4 specifications (2i〇; ^^ v issued 1-* ------- 514661 Α7 Β7 V. Description of the invention (1〇) TXR = resistivity (Please read the precautions on the back before filling this page ) Among them, T is the film thickness (A), and R is the sheet resistance (Q / cm2). For various metal films, the resistivity (Ω / cm) is a constant. The present invention uses RS from KLA-Tericor The 75 type machine measures the film thickness of the metal layer. The oxide film thickness can be directly measured by the optical principle. The present invention uses the SM300 model of KLA-Tencor company to measure the film thickness of the thermal oxide. The measuring method of the polishing rate As follows: First measure the film thickness of the metal layer with the above RS 75 machine, grind the slurry according to the above example, and grind it under the above operating conditions for 丨 minutes, and then clean it with the Evergreen Model 10X machine from Solid State Equipment Corporation. Machine cleaning wafer, after Blow the wafer dry. Then measure the film thickness T2 of the metal layer with an Rg 75 type machine. The Ti-T2 is the polishing rate of the metal layer. In addition, the film thickness τ3 of the thermal oxide was measured with a SM 300 machine. After grinding for 丨 minutes with the same slurry and the same operating conditions, the film thickness was measured to be I. T3-A is the polishing rate of thermal oxide. The test data obtained are listed in Table 1 below: Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs ___________ ~ 13- This paper size applies to the Chinese National Standard (CNS) V. Description of the invention (11) Α7 Β7 Table 1 Removal rate Example number w (A / minute) Ti (A / minute) TiN (A / minute) Si02 (A / minute) Example 1 4145 2976 983 237 Example 2 4315 2921 950 201 Example 3 5008 2337 3523 102 Example 4 5273 1368 3899 210 Comparative Example 1 572 247 687 167 Comparative Example 2 1161 1198 1695 233 (Please read the precautions on the back before filling out this page) Fei Jingdi Department Central Standard Bureau Staff Consumer Cooperative Co., Ltd. Printing Example 5 Repeat the same preparation steps as in Example 3 However, 3 kg of formic acid was used to replace Lemon Han 'and 2 kg (NH4) 2S2 08 was used to replace ammonium iron sulfate (πΐ), and the pH was adjusted to 4.0 with ammonia. The grinding test results of the obtained grinding compositions are shown in Table 2 below. Example 6 The same preparation procedure as in Example 5 was repeated, except that formic acid was replaced with 3 kg of glycine, and the pH was adjusted to 4.0 with ammonia water. The grinding and test results of the obtained grinding composition are shown in Table 2 below. Example 7 The same preparation procedure as in Example 5 was repeated, except that the acid was replaced with 3 kg of formamidine, and the pH was adjusted to 4.0 with ammonia water. Hu of the obtained grinding composition: τ grinding clam The test results are shown in Table 2 below. -14- This paper size is in accordance with Chinese National Standard (CNS) A4 (210X mm) mi -i ·-· —— mi mi 1., mu mi ^ ϋ · ϋ,-口

• I

LI 1--1 — — — — — — —— — I Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (4 () 61 Α7 ----------- Β7 _____ V. Description of the Invention (12) ~~ Daqing Example 3 Repeat the same preparation steps as in Example 5 except that (NΗ4) 2§2108 is not added. The grinding test results of the obtained grinding compositions are shown in Table 2 below. 1 Mill test A · Instrument: IPEC / Westech472 B · Condition: Pressure: 5 psi Temperature: 25X: Spindle speed: 45 rpm Platen speed: 42 rpm Pedestal type: Rodel Politex Slurry flow rate: 150 ml / min C · Wafer: ⑴ A1 thin film: purchased from silicon Valley Microelectronics, Inc., is deposited by CVD technology on a 6-inch silicon wafer with a thickness of 0.85 micron ± 5%, the purity is A1: 98.5%, Si: 1%, Cu: 0.5% (2) Ti thin film · Speaking from Silicon Valley Microelectronics, Inc., it uses CVD technology to deposit 0.5 micron ± 5 on 6-inch silicon wafer. / 〇 的 膜 (3) TiN thin film · Speaking from Silicon Valley Microelectronics, Inc., it is based on the CVD technology to deposit a thin film of 0.5 micron soil 5 0/0 on a 6 忖 Shi Xi wafer. Entrusted to the National Nanometer Component Laboratory to thermally generate the silica dioxide D · slurry on a silicon substrate: Take the slurry obtained in the above Examples 5-7 and Comparative Example 3, with the same body-15. This paper size is applicable to China Standard (CNS) A4 specification (210 '/ 297cm ^ ~ -------- —Clothing-(Please read the precautions on the back before filling out this page)-Order W4661 A7 Invention Description (13) 5. The test solution containing 5% by weight of aqueous solution of 0% is tested as described above. The test number obtained is evenly stirred for 15 minutes and is listed in Table 2 below. Table 2 ---------- Remove Rate instance number A1 (A / minute) Ti (A / minute) TiN (A / minute) Si〇2 (&quot; minute) Example 5 3944 1704 3318 129 Example 6 4682 1223 3380 117 Example 7 3552 2279 4454 112 Comparative Example 3 1705 673 3237 192 * Clothing — I (Please read the precautions on the back before filling out this page) Order the staff of the Central Bureau of Standards of the Ministry of Economic Affairs Printed by the cooperative ά- ··, | Example 8

The same preparation steps as in Example 5 were repeated, except that the pH was adjusted to 6.5 with ammonia. The grinding test results of the obtained grinding composition are listed in Table 3 below. Example 9 The same preparation steps as in Example 6 were repeated, except that the pH was adjusted to 3 6.5 with ammonia water. The grinding test results of the obtained grinding composition are shown in Table 3 below. Example 10 was repeated with the same preparation steps as in Example 7, except that 1.5 kg of acetamide was used to obtain + formic acid. The grinding test results of the obtained grinding composition are listed in the following table. 0-16 I degree is applicable to China National Standard (CNS) A4 specification (210X297 mm) ^ 14661 A7 B7 V. Description of the invention (14) Cover example 4 The same preparation steps as in Comparative Example 3 were covered, except that the pH was adjusted to 6.5 with ammonia water. The grinding test results of the obtained grinding compositions are shown in Table 3 below. Grinding measurement Α · Instrument: IPEC / Westech472 Β · Conditions: Pressure: 5psi Temperature: 25 ° C Spindle speed: 45 rpm Platen speed: 42 rpm Pedestal type: Rodel 1C 1400 Slurry flow rate: 150 ml / min C. Wafer : ⑴ Cu thin film: purchased from Silicon Valley Microelectronics, Inc., which is based on PVD technology to deposit a 0.85 micron ± 5% thin film on a 6-inch silicon wafer. (2) Ti thin film: from Silicon Valley Microelectronics, Inc. Deposition of 0.5 micron ± 5% thin film on 6-inch silicon wafer by CVD technology. Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling this page). (3) TiN thin film: speak from Silicon Valley Microelectronics, Inc., uses CVD technology to deposit a 0.5 micron ± 50/0 thin film of rhenium oxide film on a 6-inch silicon wafer: it was commissioned to the National Nanometer Component Laboratory to heat on Shixi substrate Resulting Dioxide of the Oxygen D · Slurry · Take the slurry obtained from the above example $ _10 and Comparative Example 4 and mix it with the same volume of aqueous solution containing 5% by weight of H2O2; stir for 15 minutes _-17 -Applicable to Chinese national standards as far as possible CNS) A4 specification (210X 297 mm) ^ &gt; 14661 A7 B7 V. Description of the invention (15) The test grinding test process is as described above, and the test data obtained is listed in Table 3 below: Table 3 "No. (3ιι (Λ / minute) Ti (Α / minute) Example 8 7430 -----_. 1804 Example 9 7217 1665 Example 1 0 4001 1471 Comparative Example 4 7337 598 Removal rate 4340 3677 203 211 ---, _: __ 1 # 衣 II (Please read the precautions on the back before filling in this page)

, 1T From the above examples, it can be seen that the waste phase of the present invention can make people feel poor, and the mouthpiece can effectively improve the grinding efficiency of metal films, especially Ti and TiN films, # 浐 合

Wu Yazhi's grinding selectivity for Cu / Ti and Cu / TiN. Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs -18-

Claims (1)

514661 Patent Application No. 0871〇6624 B8 C8 Chinese Patent Application Scope Amendment (October 91) D8 6. Patent Application Scope 1. A chemical mechanical polishing composition for polishing metal thin films in a semiconductor process, comprising 1-25% by weight of abrasive particles; 0.1-20% by weight of a buffering agent as a grinding accelerator, wherein the buffering agent includes a compound containing a persulfate group or a salt containing iron (III) and a carboxyl group or amidino group Compounds; and 1-10% by weight of an oxidizing agent, wherein the persulfate group-containing compound is selected from the group consisting of H2S208, K2S208, (NH4) 2S208, Na2S208, and mixtures thereof, and the iron (III) -containing salts are Selected from the group consisting of potassium ferricyanide, iron (III) ammonium sulfate, iron (III) nitrate and mixtures thereof, the carboxyl-containing compound is selected from the group consisting of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, Glycolic acid, lactic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, hydroxysuccinic acid, tartaric acid, galactonic acid and citric acid, and their salts, and these acids and / or their salts A group of mixtures of The amido-containing compound is selected from the group consisting of formamide, acetamide, propylamine, N-methylformamide, N-methylacetamide, urea, methylurea, ethylurea, and dimethylurea. And diethylurea, and the abrasive is selected from the group consisting of Si02, Al2O3, Zr02, Ce02, SiC, Fe203, Ti02, Si3N4, or a mixture thereof, and the oxidant is selected from the group consisting of A group consisting of H202, KI03, KBr03, K2Cr207, K2Mη207, KMn04, HOC1, CH3COOOH, and mixtures thereof. 2. The composition according to item 1 of the scope of patent application, which comprises 3 to 10% by weight of the abrasive particles; and 6 to 15% by weight of the buffering agent as a grinding accelerator. O: \ 52 \ 52484-911004.DOC \ 5 · 1 · This paper size applies to China National Standard (CNS) Α4 size (210X 297 mm) binding Line 514661 8 8 8 8 A B c D, scope of patent application 3 · The composition according to item 1 of the scope of patent application, which contains 4-6% by weight of the oxidant. -2- O: \ 52 \ 52484-911004.DOC \ This paper size applies to China National Standard (CNS) A4 specification (210 x 297 mm)