TW574352B - Chemical mechanical abrasive slurry composition and method of using the same - Google Patents

Abstract

The invention provides a chemical-mechanical abrasive slurry composition for semiconductor processing, which comprises 70-99.5 wt.% of an aqueous medium; 0.1-25 wt.% of an abrasive particle; 0.01-1 wt.% of a corrosion inhibitor; and 0.01-1 wt.% of a chemical selected from the group consisting of a glycol compound and 2-hydroxy carboxylic acid compound and a mixture thereof. The chemical-mechanical abrasive slurry composition of the invention may further comprise an oxidant. The invention also pertains to the use of the composition in a method for polishing the surfaces of semiconductor wafers.

Description

574352

FIELD OF THE INVENTION The present invention relates to a chemical mechanical polishing slurry composition. The polishing composition of the present invention can be effectively applied to polishing the surface of a semiconductor wafer. BACKGROUND OF THE INVENTION Chemical Mechanical Polishing (CMP) is a flattening technology developed to solve the difficulty of focusing on the lithography process due to the difference in coating height during the manufacture of integrated circuit (IC). Chemical mechanical polishing technology was first applied in a small amount to the manufacture of 0.5-micron components. As the size of chemical mechanical polishing was reduced, the number of layers of chemical mechanical polishing was increasing. By the 0.25 micron generation, chemical mechanical polishing has become the mainstream and necessary planarization technology. Generally speaking, the polishing method for manufacturing metal circuits is to place a semiconductor wafer on a rotary polishing table equipped with a polishing head, and apply a polishing slurry containing abrasive particles and an oxidant on the surface of the wafer to improve the polishing 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, HOC1, K 0 C 1, K M g 0 4 or C C 3 C 0 OO Ο. This polishing liquid is used to polish the copper layer on the semiconductor wafer to make copper wires on the wafer. U.S. Patent No. 5,209,816 discloses a method for polishing a metal layer containing A1 or Ti using a chemical mechanical polishing polymer solution. The polishing slurry contains about 0.1-20 vol% H3P04 and U0 vol% H202. U.S. Patent No. 4,9 5 9, 1 1 3 is related to the use of water-based abrasive composition -4-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

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Line 574352 A7 B7 V. Description of the invention (2) A method for polishing a metal surface "This aqueous abrasive composition contains water, an abrasive (such as Ce02, Al2O3, Zr02, Ti02, Si02, SiC,

SnO2 and TiC), and a salt containing a metal cation of group IIA, IIIA, IVA or IVB of the periodic table with chloride ion, bromide ion, iodide ion, nitrate, sulfate, phosphate or ion Anion of chlorate. This U.S. patent also teaches the use of hydrochloric acid, nitric acid, phosphoric acid, or sulfuric acid to formulate its aqueous grinding composition to pH = 1-6. U.S. Patent No. 5,391,258 discloses an abrasive composition for polishing a composite containing hard, silica, or silicate, which, in addition to abrasive particles, also contains hydrogen peroxide and g peracid hydrogen (potassium hydrogen phthalate) ° U.S. Patent No. 5,114,437 relates to a polishing composition for polishing aluminum substrates, which includes an oxide I polishing agent having an average particle size of 0.2 to 5 μm, and is selected from chromium nitrate (ΠΙ) Polishing accelerators for lanthanum nitrate, ammonium (in) ammonium nitrate or neodymium nitrate. US Patent No. 5,084,07 No. 1 relates to a method for polishing electronic component substrates by using a chemical mechanical polishing slurry. The polishing slurry used contains less than 1% by weight of alumina, abrasive particles (for example, S i 〇 2, Ce02, SiC, Si3N4 or Fe203), a transition metal chelate salt (eg, EDT A ferric ammonium) as a grinding efficiency promoter, and a solvent for the salt. U.S. Patent No. 5,336,542 discloses a polishing composition comprising oxidized chain abrasive particles and a chelating agent selected from a polyamine carboxylic acid (e.g., EDTA) or a steel or salt thereof. This polishing composition may further include boehmite

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Line A7 B7 3 V. Description of the invention (Boehmite) or Ming salt. U.S. Patent No. 5,3 40,3 7 0 discloses a slurry for chemical mechanical polishing of, for example, tungsten or tungsten nitride films, comprising Potassium ferricyanide oxidant, abrasive and water for film, wherein the slurry has a pH value of 2 to 4. U.S. Patent No. 5,516,34 6 discloses a slurry for chemical mechanical polishing of thin films, which contains a concentration Potassium fluoride and abrasives (such as silicon oxide) sufficient to blend with the titanium film, where the slurry has a pH value below 8. WO 96/16436 discloses a chemical mechanical polishing slurry comprising Medium-diameter abrasive particles, iron salt oxidants, and aqueous surfactant suspensions of propylene glycol and methyl parahydroxybenzoate. Salts commonly used to promote grinding rates include iron ions (such as Fe (N〇3) 3 or K3Fe (CN) 6) or potassium ions (such as KI〇3), however, these metal ions will contaminate wafers and CMP equipment, increase the workload of subsequent cleaning and reduce the useful life of CMP process equipment. In addition, Has considerable mobility It is easy to penetrate the dielectric layer and reduce the reliability of the IC. In the 1C process, Ta or TaN films are often used to improve the adhesion of copper to the silicon oxide insulation layer. In addition, Ta or TaN films are also used as barrier films In theory, the removal rate of Ta or TaN should be similar to the removal rate of Cu, but Ta metal is a highly chemically resistant metal. Because it is not easy to oxidize, in the copper process, the grinding of Ta metal has always been The most difficult to overcome in the art. At the same time, because the barrier film is difficult to remove, it often leads to the problem of copper wire depression. In addition, in this copper process, the copper film will be tempered. --ft This paper size applies to China National Standard (CNS) A4 (210X297 mm)

= And it is easy to produce a dense layer of copper oxide on the copper film. And because of the uniformity of the CMP I%, when the copper on the wafer has been abraded and pits have started to form, unwanted copper often remains on the wafer. Therefore, how to quickly remove copper residues to reduce copper wire sags and accelerate production capacity is a major issue that CMP processes need to overcome. In summary, in the semiconductor process technology, there is still an urgent need for chemical mechanical polishing compositions that are more economical, more efficient, and can reduce the above disadvantages. Disclosed briefly, the present invention provides a chemical mechanical polishing slurry composition for use in semiconductor manufacturing processes, which contains 70-99.5 wt% of an aqueous medium; 〇1-25 wt% of abrasive particles; Inhibitors and 001_1% K are selected from the group consisting of glycolates and 2-hydroxycarboxylic acid compounds and mixtures thereof. The chemical mechanical polishing slurry composition of the present invention may further contain an emulsifier. The present invention also relates to a method for using the composition for polishing the surface of a semiconductor wafer. Detailed description of the invention The chemical mechanical polishing slurry composition system of the present invention comprises 70-99.5% by weight 'preferably 80-99.5% by weight of an aqueous medium; 〇__25% by weight, preferably 0.5-10% by weight, And more preferably 0.5-5% by weight of abrasive particles; 0.01-1.0% by weight, more preferably 0.01_0 · 5% by weight, and most preferably 0.05-0.2% by weight corrosion inhibitor; and 001_1 ()% by weight of this paper selected from the group consisting of glycolates and 2-hydroxycarboxylic acid compounds and their mixtures applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 574352

Chemicals. The chemical-mechanical abrasive composition of the present invention can further scour the oxidizing agent by weight. According to the embodiments of the present invention, it is known that the addition of a diol or a 2-¾-based citric acid to the abrasive slurry towel can prevent the occurrence of copper sags.

According to the present invention, the grinding particles used for grinding the slurry composition may be general commercial ones, such as Si02, Al203, Zr02, Ce (^^,: e203, T "02, Si3N4 or The mixture of these abrasive particles has the advantages of higher purity, high surface area, and narrow particle size, so it is suitable for use as abrasive particles in the abrasive composition. The choice of the aqueous medium containing the abrasive slurry composition of the present invention, Those who are familiar with this technology, τ, is obvious and easy to know. For example, water can be used in the preparation process, and preferably deionized water is used to make the grinding composition slurry.

According to the present invention, the corrosion inhibitor used in the polishing slurry composition is a triazole compound, which can be selected from benzotriazole, cyanuric acid (1,3,5_uiazine_2,4,6-triol), 1,2 , 3-triazole, 3-amino-1,2,4-triazole, 3 · nitro-1,2,4-triazole, pui: paid®, benzotriazole_5- Carboxylic acid, 3 • amino1,2,4-triazole-5-carboxylic acid, 1 · hydroxybenzotriazole, and nitrobenzotriazole; benzotriazole is preferably used. According to the present invention, the diol compound used in the grinding slurry composition is a compound having the following structural formula: OH 0H Rl-CH-CH-R2 -8- This paper size applies to China National Standard (CNS) A4 (210X 297) (Centi) 574352 A7 B7 V. Description of the invention (wherein R and r2 are selected from fluorene or Ci-Cb alkyl, respectively. The diol compound suitable for use in the present invention may be, for example, ethylene glycol, cardiac propylene glycol, Glycol or 2,3 · butanediol, preferably ethylene glycol or α-propylene glycol, most preferably ethylene glycol. According to a preferred embodiment of the present invention, the composition of the present invention contains 0.001- 1.0% by weight, preferably 0.001-0.55% by weight, and more preferably 0.1-0.4% by weight of ethylene glycol. According to the present invention, the 2-hydroxycarboxylic acid used to grind the slurry composition Compounds with the following structural formula: ΟΗ

R——CH—COOH where R is fluorene or Ci-C6: fe group. The 2-hydroxy-acid acid suitable for use in the present invention may be, for example, 2-hydroxyacetic acid, 2-hydroxypropionic acid, or 2-hydroxybutyric acid. Preferably, it is 2-hydroxyacetic acid or 2-hydroxypropionic acid, and most preferably It is 2-glycolic acid. According to a preferred embodiment of the present invention, the composition of the present invention may contain 0.001-1.0 wt%, preferably 0.001-05 wt%, and more preferably 0.1-0.4 wt% of 2-hydroxyl. Acetic acid. According to the present invention, the oxidant used to grind the slurry composition is a component known in the chemical mechanical polishing technology, and it can be freely selected.

Fe (N〇3) 3, KI〇3, ch3COOOH and KMη04; preferably η2ο2. According to the present invention, when the deionized water is 80 to 99.5% by weight, the solid of the slurry is applied to the paper standard (CNS) M specification (21GX297)

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The content is 0.5-15% by weight, preferably 0.5-10% by weight, and more preferably 0.55% by weight I%. Each component as described above is then introduced into the resulting slurry of the same purity, and then an acid or alkali is added to control the pΗ value of the slurry to a desired range. The invention also relates to a method for polishing the surface of a semiconductor wafer, which comprises applying a chemical mechanical polishing slurry composition according to the invention on the surface of the wafer. The following examples will further illustrate the present invention, but are not intended to limit the scope of the present invention. Modifications and changes that can be easily achieved by anyone skilled in the art are all included in the scope of the present invention ^ Grinding test A · Instrument : AMAT / Mi rra B. Conditions and Membrane Pressure: 2psi

Inner Tube: Vent Retaining Ring · 2.6psi Platen Speed · 93rpm Carrier Speed · 87rpm Temperature: 25 ° C Type of polishing pad: IC 1 000, k-xy. Slurry flow rate: 150 ml / min. C. Wafer · patterned wafer, purchased from Semitech, model: 0 · 25μιη line width 854CMP017 wafer. D · Slurry: Take the slurry obtained from the example and 30% Η2 02 in a 9: 1 body * " 1 .........-λ η This paper size applies to China National Standard (CNS) Α4 specification (210X297) %)

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574352 A7 B7 V. Description of the invention () 8 After the product ratio is evenly dropped, test it. Grinding test process: The invention uses the Mirra grinding machine of Applied Materials to perform grinding. The grinding process uses the signal generated by the End Point System as the end point (EP2) signal to determine. During grinding, the slurry in the example was ground to EP2 and then over-polished by 20%. After polishing, the wafers were cleaned with Evergreen Model 10X cleaning machine from Solid State Equipment Corporation. After cleaning, the wafers were blown dry with nitrogen (N2). Then use KLA-Tencor P-1 1 Surface Profiler contact surface profiler to measure the degree of copper sag (Dishing), the copper wire with a line width of 100 micrometers (μπ) as the measurement point, and its barrier layer (Barrier) Layer). Example 1 A colloidal silica was used as abrasive particles to prepare a slurry. The composition of the polymer solution is as follows, and the results of the grinding test are shown in Table 1. Silica gel content: 2.0% by weight; benzotriazole (BTA): 0.1% by weight; the rest are ammonia or nitric acid and deionized water with adjusted pH. Example 2 A slurry was prepared in the same manner and composition as described in Example 1, except that formic acid was added in an amount of 0.2% by weight. The results of the grinding test are shown in Table 1. Example 3 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

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V. Description of the invention (Slurry was prepared in the same manner and composition as described in Example 1, but 0.2% by weight of adipic acid was added. Its grinding test results are shown in Table 1. Example 4 was the same as described in Example 1. The composition was prepared as a slurry but aminoacetic acid was added in an amount of 0.2% by weight. The grinding test results are shown in Table 1. Example 5 A slurry was prepared in the same manner as the composition as described in Example 2, but ethylene glycol was added as an additional 0.2% by weight. The results of the grinding test are shown in Table 1. Example 6 A slurry was prepared in the same manner and composition as described in Example 3, but an additional 0.2% by weight of ethylene glycol was added. The results of the grinding test are shown in Table 1. Example Ί — Prepare the slurry in the same manner and composition as described in Example 4, but with the addition of ethylene glycol 0.2 weight section 'The grinding test results are shown in Table 丨. Example 8 is the same as Example 7, except that the pH value is changed to 5-6 In the meantime, the grinding test results are shown in Table 1. Example 9 A slurry was prepared in the same manner and composition as described in Example 3, but 0.4% by weight of ethylene glycol was additionally added, and the grinding test results are shown in Table 丨. Example 1 0 Phase 6 , Only changed to alumina abrasive particles, which was triturated test results shown in Table 1. Example 1 1 - - Paper This applies China National Standard Scale (CNS) A4 size (210 X 297 mm)

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Line 574352 A7 B7 V. Description of the invention (1 ()) The grinding test is the same as in Example 3, except that alumina is used as the abrasive particles. The results are shown in Table 1. Example 1 2 A slurry was prepared in the same manner as the composition described in Example 3, but an additional 0.2 weight was added. The results of the grinding test are shown in Table 1 below. Example 1 3 was the same as Example 12, except that alumina was used as the abrasive particles. The grinding test results are shown in Table 1. -This paper size is in accordance with Chinese National Standard (CNS) A4 (210X 297 mm) 574352 A7 B7 V. Description of the invention (n) • ί / Table 1 Examples of abrasive particles, solid content (%), chemicals added and their Content (wt%) pH depression (A / 100 micron line width) Cu 1 Silica gel 2 Benzotriazole (0.1%) 3-4 1213 2 Silica gel 2 Benzotriazole (0.1%) Formic acid (0.2 %) 3-4 1617 3 Silica gel 2 Benzotriazole (0.1%) Adipic acid (0.2%) 3-4 1530 jfl 4 Silica gel 2 Benzotriazole (0.1%) Glycine (0.2%) 3-4 1593 5 Silica gel 2 Benzotriazole (0.1%) Formic acid (0.2%) Ethylene glycol (0.2%) 3-4 659 6 Silica gel 2 Benzotriazole (0.1%) Adipic acid ( 0.2%) Ethylene glycol (0.2%) 3-4 544 7 Silica gel 2 Benzotriazole (0.1%) Glycolic acid (0.2%) Ethylene glycol (0.2%) 3-4 631 ίτ 8 Silica gel 2 Benzotriazole (0.1%) Adipic acid (0.2%) Ethylene glycol (0.2%) 5-6 537 9 Silica gel 2 Benzotriazole (0.1%) Adipic acid (0.2%) Ethylene glycol ( 0.4%) 3-4 553 * 4 10 alumina 2 benzotriazole (0.1%) adipic acid (0.2%) ethylene glycol (0.2%) 3-4 1139 11 alumina 2 benzotriazole (0 .1%) adipic acid (0.2%) 3-4 1802 12 Silicic acid gel 2 benzotriazole (0.1%) adipic acid (0.2%) 2-glycolic acid (0.2%) 3-4 613 13 alumina 2 Benzotriazole (0.1%) adipic acid (0.2%) 2-alcohol-acetic acid (0.2%) 3-4 1187 -14- This paper size applies to China National Standard (CNS) A4 (210x 297 mm) ) 574352 A7 B7

V. Description of the invention (Comparison of the results of Examples 1 to 7 shows that copper sag can be prevented after the addition of ethylene glycol to the grinding slurry. The results of Comparative Examples 6 and 8 show that the addition of ethylene glycol to the grinding liquid of different pH values It can prevent copper sag. Comparing the results of Examples 6 and 9, it can be seen that copper sag can be prevented by adding different concentrations of ethylene glycol to the grinding slurry. Comparing the results of Examples 3 and 6 and Examples 10 and 11, it can be seen that ethylene glycol The additions are suitable for grinding slurry with silicic acid glue and alumina as abrasive particles, and both can achieve the effect of preventing copper sag. Comparing the results of Examples 3 and 12 and 11 and 13, it can be seen that 2_ It can also prevent the copper from sinking.

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____- 15- This paper size applies to China National Standard (CNS) A4 (210X 297 mm)

Claims (1)

574352 A8 B8 C8 D8 1. A chemical mechanical polishing. A slurry composition comprising 70-99 5 wt% of an aqueous medium; 0 · 1-2 5 wt% of abrasive particles; 0 · 〇i · 1 wt% of corrosion Inhibitors; and 0.001 to 1% by weight of chemicals selected from the group consisting of glycolates and 2-quinocarboxylates and mixtures thereof, wherein the glycolates have the following structural formula: OH OH r'-ch-ch-r2 wherein R1 and R2 are respectively selected from alkyl groups, and the 2-hydroxycarboxylic acid compound has the following structural formula: 〇Η R——CH——COOH wherein R is an alkyl group. 2. The composition according to item 1 of the scope of the patent application, wherein the abrasive particles are selected from the group consisting of Si02, Al2O3, Zr02, Ce02, Sic, Fe A c 2 vJ 3, Ti02, Si3N4 and mixtures thereof. 3. The composition according to item 丨 of the scope of patent application, which comprises 0.5 to 10% by weight of abrasive particles. 4. The composition according to item 3 of the scope of the patent application, which contains 0 _ -16-this paper size is applicable to a family standard (CNS) Α4 specification (21GX 297 male '-_ 574352 A8 B8 C8 Amount of abrasive particles. 5. The composition according to item i of the claimed patent scope, wherein the diol compound is ethylene glycol. 6. The composition according to item 5 of the scope of patent application, which contains ethylene glycol in an amount of 0 q%. 7. The composition according to item 5 of the scope of patent application, which comprises 0% by weight of ethylene glycol. 8. The composition according to item 丨 scope of patent application, wherein the 2-hydroxycarboxylic acid compound is 2 -Glycolic acid. 9. The composition according to item 8 in the scope of the patent application, which contains 0 is 2% by weight of 2-glycolic acid. 10. The composition according to item 8 in the scope of the patent application, which contains 0 丨 _ 〇 · 4% by weight of 2-guinea acetic acid. 11. The composition according to item 丨 of the scope of patent application, wherein the corrosion inhibitor is a triazide. 12_ The composition according to item 11 of the scope of patent application, wherein The trisialylate is benzotriazole. 13. The composition according to item 1 of the scope of the patent application, which further comprises 5% by weight of oxidant. 14. The composition according to item 13 of the scope of patent application, wherein The oxidant is selected from the group consisting of Η202, Fe (N03) 3, KI〇3, CH3C000H, and KMn04. 15. The composition according to item 14 of the scope of patent application, wherein the oxidant is H202 〇-17- This paper Standards apply to Chinese National Standards (CNS) A4 size (210 X 297 mm) 574352 16. The composition according to item i of the patent application scope, which comprises 80-99 5 wt% of an aqueous medium. 17. The composition according to item 16 of the application, wherein the aqueous medium is deionized water. 18. A method for polishing the surface of a semiconductor wafer, which comprises applying a chemical mechanical polishing slurry composition according to any one of claims 1 to 17 of the scope of patent application on the wafer surface. -18- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 3! .. Public application date f 〇 Case No. 091 Category —rH (The above columns are filled by the Office) A4 C4 Chinese Manual Correction Page (November 91) 574352%-^ r Patent Specification Chinese $ 1 Name Chemical Mechanical Polishing Slurry Composition and Method of Use English CHEMICAL MECHANICAL ABRASIVE SLURRY COMPOSITION AND METHOD OF USING THE SAME Name Nationality-Invention One The living and residence of the creator 1. Liu Wenzheng WEN CHENG LIU 2. Li Zonghe and TSUNG-HOLEE 3. Chen Yanliang YEN LIANG CHEN Both ROC 1 · No. 12, Lane 37, Dayi Road, Zhongli Village, Linyuan Township, Kaohsiung County NO. 12, LANE 37 , DAYIRD., LINYUAN SHIANG, KAOHSIUNG COUNTY, TAIWAN, ROC 2.No. 12, DAPING RD., LIGANG SHIANG, PINGTUNG COUNTY, TAIWAN, ROC, Pingtung County 3. Wuyuan, Dongshan Township, Yilan County No. 329, Cunwuhan Second Road NO. 329, WUHAN 2nd RD., WUYUAN VILLAGE DUNGSHAN —SHIANG, ILAN COUNTY. TAIWAN, ROC · _ Binding Nationality III. Applicant £ Former name Changxing Chemical Industry Co., Ltd. ETERNAL CHEMICAL CO., LTD. ROC No. 578, Jianong Road, Sanmin District, Kaohsiung City 578, CHIEN KUNG RD., KAOHSIUNG, TAIWAN, ROC WEN-HSIUNG YA NG This paper size is suitable for financial standards (CNS) M specifications (⑽χ⑽ 公 董) line