TW581804B - 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 to 99.5 wt.% of an aqueous medium, 0.1 to 25 wt.% of abrasive particles, 0.01 to 1 wt.% of a triazole compound as a corrosion inhibitor, and 0.001 to 1 wt.% of a water-soluble chloride ion source. According to the invention, the water-soluble chloride ion of the abrasive slurry composition could wear away during a polishing process the fine layer produced on the surface of a copper film due to an annealing treatment, and to reduce the amount of copper residues on the film after polishing. The chemical-mechanical abrasive slurry composition of the invention may optionally comprise an oxidant. The invention also relates to a process for polishing the surface of a semiconductor wafer by using the said composition.

Description

581804 Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs A7 B7 V. Description of the Invention (1) ^ ^ Field of the Invention The present invention relates to a chemical mechanical polishing slurry composition. The polishing slurry 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) technology is a planarization 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. With the reduction in size, the number of chemical mechanical polishing applications is increasing. By the 0.25 micron generation, chemical mechanical polishing has become a 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, KOC1, KMg04 or CH3COOOH. This polishing slurry is used to polish the copper layer on the semiconductor wafer to manufacture the copper wires on the wafer. U.S. Patent No. 5,209,816 discloses a method for polishing a metal layer containing A 1 or Ti using a chemical mechanical polishing slurry. The polishing slurry contains, in addition to solid abrasives, about 0.1-20% by volume of H3P04 and About 1-30% by volume of H2O2 ° U.S. Patent No. 4,959,113 relates to a method for polishing a metal surface using an aqueous abrasive composition. This aqueous abrasive composition contains water and abrasives (Example -4-This paper size is applicable to Chinese National Standard (CNS) A4 specifications (21〇 ×: 297mm) (Please read the precautions on the back and fill in this note)

—: 1Τ11., Ψ 581804 Printed by the Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs A7 B7 V. Invention Description (2) Such as Ce02, Al2O3, Zr02, Ti02, Si02, SiC, Sn02 and TiC), and a salt This salt contains anions of metal cations of group HA, ιπα, IVA or IVB of the periodic table and chloride, bromide, moth, nitrate, sulfate, phosphate or perchlorate anions. This U.S. patent also teaches the use of salt, 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 a method for polishing silicon-containing, crushed stone, or crushed acid salts. In addition to the abrasive particles, the composite abrasive composition also includes hydrogen peroxide and potassium hydrogen phthalate. U.S. Patent No. 5,114,437 relates to a polishing composition for polishing a 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 accelerators of rhenium (III) ammonium nitrate or neodymium nitrate. U.S. Patent No. 5,084,071 relates to a method of using a chemical mechanical polishing slurry to polish electronic component substrates. The polishing slurry used contains less than 1% by weight of alumina and abrasive particles (for example, Si02, Ce02, SiC, Si3N4 or Fe203), transition metal chelating salts (such as' EDTA ferric ammonium) as a grinding efficiency promoter, and solvents for the salts. U.S. Patent No. 5,336,542 discloses a polishing composition including oxide abrasive particles and a chelating agent selected from a polyamine carboxylic acid (e.g., EDTA) or its sodium or potassium salt. This polishing composition may further include boehmite or an aluminum salt. U.S. Patent No. 5, 3 40, 3 7 0 Tiger uncovers a slurry for chemical mechanical polishing of, for example, iron or nitride film, which contains potassium ferricyanide-5 for film use-this paper size Applicable to China National Standard (CNS) A4 specification (210X 297mm) (Please read the precautions on the back before filling out this page) Binding · ---- 581804 Employees' cooperation with the Central Standards Bureau of the Ministry of Economic Affairs 衽 Printing A7 B7 5 2. Description of the invention (3) Chemical agent, abrasive and water, wherein the slurry has a pH value of 2 to 4. U.S. Patent No. 5,516,346 discloses a titanium film < slurry for chemical mechanical polishing, which comprises potassium fluoride and an abrasive (e.g., oxidized pulverizer) at a concentration sufficient to blend with the titanium film, wherein the slurry has a value below. WO 96/16436 discloses a chemical mechanical polishing slurry comprising abrasive particles having a median diameter of less than 0.400 micrometers, an iron salt oxidant, and an aqueous surfactant suspension of propylene glycol and methyl parahydroxybenzoate. Salts commonly used to promote the polishing rate contain 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 can contaminate wafers and CMP equipment , Increase the workload of subsequent cleaning and reduce the life of the CMP process equipment. In addition, potassium ions have considerable mobility, easily 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 insulating layer. In addition, a Ta or TaN film is also used as the metal of the barrier film. Theoretically, the removal rate of Ta or TaN should be similar to the removal rate of Cu. However, Ta metal is a metal with high chemical resistance. Because it is not easy to oxidize, the polishing of Ta metal has always been the most advanced technique in the copper process. Insurmountable At the same time, the barrier film is difficult to remove, which often causes the copper wire to sag. In addition, in this copper process, the copper film is subjected to an annealing process, which is likely to produce a dense layer of copper oxide on the copper film. And because of the uniformity of the cMp process, when some copper on the wafer has been abraded and recesses have begun to be produced, there is often unwanted copper left on the wafer. Therefore, how to quickly remove the copper residue to reduce the depression of the steel wire and accelerate the production capacity is-6 (CNS) (210X297 ^^ 7 clothing — (Please read the precautions on the back before filling out this page) —: 1TI — Ψ A7 B7 581804 V. Description of the invention (4) A major problem that the CMP process has to overcome. In the iC semiconductor process technology, it is still urgent to seek a more economical, more efficient chemical mechanical polishing composition that can reduce the above disadvantages. The present invention provides a chemical mechanical polishing slurry for use in semiconductor manufacturing processes, and the finished product contains 7G to 99 5 wt% of aqueous medium; w to "wt% of flour"; magic weight % Is used as the source of water-soluble chloride ion with three bites and 0.001 to 1% by weight. The chloride ion in the aqueous solution contained in the polishing slurry composition of the present invention can be worn through during tempering due to tempering treatment. The dense layer produced on the surface of the steel film, and the amount of copper residues after lapping can be reduced. The chemical mechanical polishing slurry composition of the present invention can be further L; the oxidant. The present invention also relates to the composition for polishing semiconductor wafers Detailed description of the invention The chemical mechanical polishing slurry composition of the present invention comprises 70 to 99.5% by weight and preferably 80 to 99.5% by weight of an aqueous medium; ^ "to"% by weight, preferably 0.5 to 15% by weight " , More preferably 05 to 10% by weight, and most preferably 05 to 5% by weight of abrasive particles; 0.01 to 1.0% by weight, preferably 0.01 to 0.5% by weight, and more preferably 0.05 to 0.2% by weight Corrosion inhibitor, and water-soluble chloride ion source of 0.00 to 1% by weight, preferably 0.01 to 0.5% by weight, and more preferably 0.02 to 0% by weight. The chemical mechanical polishing slurry of the present invention The composition may further include an oxidizing agent in an amount of 0.00 to 5% by weight. According to the examples of the present invention, it is known that the emulsion slurry is added to the polishing slurry composition to penetrate through the dense layer on the copper surface and reduce the copper residual amount. Ί Ί — This paper size applies to Chinese National Standards · (CNS) A4 size (210X297 male shame) (Please read the precautions on the back before filling this page)-"Order

P Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 581804 V. Description of the invention (5) 1 = Non-chlorine-containing compounds that dissociate from chloride ions in aqueous media, ... Hydrogen chloride, gas M, n A ^ Synthetic rat ion source, Example female, monomethotamine hydrochloride, tetramethylammonium chloride, and hemicarbazine hydrochloride. τ volume bismuth and: According to the present invention, the abrasive particles used in the abrasive slurry composition may be described as: seller: e.g. si02, A1203, ZK) 2, ce () 2, sic 2 3 / lG2, Sl3N4 or mixtures thereof . These abrasive particles have advantages such as high specific gravity, specific surface area, and narrow particle size distribution, and are therefore suitable for use as abrasive particles in abrasive compositions. The selection of the aqueous medium of the grinding slurry composition of the present invention is obvious to those skilled in the art. For example, in the preparation process, η: water can be used, and preferably deionized water is used to make The polishing composition was in the form of a slurry. According to the present invention, the corrosion inhibitor used in the polishing slurry composition is a tertiary compound, which may be selected from benzotriazine, cyanuric acid (u, 5th, zi_2, 4, 6_triol), 1, 2 , 3-diazole, 3-amino-1,2,4-triazole, 3-nitro-, 2,4-triazole, purpald, benzotriazole-5_carboxylic acid ,% Amine group, 2,4_ triazole-5 carboxylic acid, b-hydroxybenzotriazole, and nitrobenzotriazole; benzotriazole is preferred. Employees' Cooperatives, Central Standards Bureau, Ministry of Economic Affairs According to the present invention, the oxidant used to grind the slurry composition is a component known in the chemical mechanical polishing technology, which can be selected from h202, Fe (N〇3) 3, KI〇3, CH3COOOH, and KMn. 4; Preferably, h2O2 is used. According to a preferred embodiment of the present invention, when the deionized water is 99-5 wt%, the solid content of the slurry is 0.5-15 wt%, preferably 0.5-5 10% by weight, and more preferably 0.5 to 5% by weight. The paper sizes as described above will then apply the Chinese National Standards (CNS) M specifications (210X297 mm) 刈 1804 employees of the Central Standards Bureau of the Ministry of Economic Affairs A7 printed by Fei Cooperative Co., Ltd. 5. Description of the invention (6) The components are introduced into the high-purity slurry, and then acid or alkali is added to control the p 所需 value of the slurry to a desired range. The present invention also relates to a polished semiconductor wafer The surface method includes applying a chemical mechanical polishing slurry composition according to the present invention on a wafer surface. The following examples will further illustrate the present invention, but are not intended to limit the scope of the present invention, anyone familiar with this technology Modifications and changes that can be easily achieved by those skilled in the art are within the scope of the present invention. Grinding test A. Instrument · IPEC / Westech 4 72 B. Conditions: Pressure: 2p si Back pressure: 0.5ps i Temperature: 25 ° C Spindle speed: 93rpm Platen speed: 87rpm Type of pedestal · IC1000, k-grv · Slurry flow rate: 250 ml / min C · Wafer: Copper film, purchased from siiiC0I1 Valley Microelectonics.

Inc · 'It is deposited on a 8-inch silicon wafer with 1,000-person silicon oxide thermal oxide, 300 A of PVD_Ta, and 1000 Å ± 5% of a PVD copper film. The copper wafer was tempered in an oven at 100 ° C. D. Polymer solution: The slurry obtained in the example is stirred with 30% η 2 02 in a volume ratio of 9: 1 and then tested. Grinding test process: This paper size applies the Chinese National Standard (CNS) Α4 specification (21〇 > < 297 public director ---- Shang! F Please read the precautions on the back before filling this page) -Order I.—

581804 A7 B7 V. Description of the invention (7) Before and after grinding, the thickness of the film must be measured with a film thickness tester. Measure the sheet resistance of the thin film of the metal film with a four-point probe. The film thickness is converted by the following formula: τ XR = resistivity where T is the film thickness (Λ) and R is the sheet resistance (i2 / crn2). For various metal films, the resistivity (Ω / cm) is a constant. In the present invention, the thickness of the metal layer was measured using a RS 75 machine from KLA · Tencor. The method of measuring the polishing rate is to first measure the metal layer film thickness T 1 with the RS 75 machine, and grind the slurry obtained in the example for 1 minute, and then use Evergreen from Solid State Equipment Corporation

After the wafer was cleaned by Model 10 × machine, the wafer was blown dry. The thickness of the metal layer was measured with a μ 75 machine. Let T — T2 be the polishing rate of the metal layer. Example 1 A slurry was prepared using colloidal silica as abrasive particles. The polymer composition is as follows: colloidal silica: 2.0% by weight; benzotriazole (BTA): 0.1% by weight; printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page) The content is ammonia water or nitric acid and deionized water whose pH is adjusted. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. Example 2 A slurry having the same composition as described in Example 1 was prepared, but 0.2% by weight of nitric acid was additionally added. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. This paper size applies Chinese National Standards (CNS) M specifications (210X297 mm) M1804 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs. 5. Description of the invention (Example 3 Preparation and Example) A slurry with the same composition is described, but added. • 2% by weight of phosphoric acid. The grinding rate and the time of grinding through the dense layer of the obtained grinding slurry are shown in Table 丨. Example 4 A slurry having the same composition as that described in Example 1 was prepared, but sulfuric acid was additionally added. The grinding rate of the obtained grinding slurry When it is worn through the dense layer, it is shown in Table 1 between 0.2% by weight and 5% (please read the precautions on the back before filling this page). Preparation and preparation of the slurry consisting of the phase HI described in Example 1, but additional 〇2 % By weight of hydrogen chloride. The grinding rate and the time of grinding through the dense layer of the obtained grinding slurry are shown in Table 丨 f Example 6 A slurry having the same composition as described in Example 1 was prepared, but 0.2% by weight of ammonium gasified was additionally added. The grinding rate of the obtained grinding slurry and the time of grinding through the dense layer are shown in Table 丨. A slurry having the same composition as described in Example 5 was prepared, except that alumina was used as the grinding particle instead of colloidal silica. The grinding rate of the obtained grinding slurry and the time of grinding through the dense layer are shown in Table 丨. Example 8 A slurry having the same composition as described in Example 5 was prepared, but the ρΗ value was adjusted to 6. Known grinding rate of the grinding liquid The time between wear and wear of the dense layer is shown in Table 5 to Table 5.

-11-μ's scale is suitable for financial affairs. I-581804 A7 ^^ 一 _ 一 --___ V. Description of the invention (9) Prepare a slurry with the same composition as described in Example 5, except that the pH value is adjusted. It is between 2 and 3. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. A slurry having the same composition as described in Example 5 was prepared except that the amount of hydrogen chloride was changed to 0.05% by weight. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. A slurry having the same composition as described in Example 5 was prepared except that hydrogen chloride was replaced with 0.1% by weight of dimethylamine hydrochloride. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. A slurry having the same composition as described in Example 5 was prepared, except that hydrogen chloride was replaced by ^ weight% of tetramethylammonium chloride. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. Printed by the Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the precautions on the back before filling this page). Prepare a slurry with the same composition as described in Example 5, except that the gasification is replaced by 0.1% by weight of hydrogenated half card. hydrogen. Table 1 shows the grinding rate and time of grinding through the dense layer of the obtained grinding slurry. π-scale scale suitable financial relationship rate αχ29ϋΊ ------ 581804 A7 B7

Five examples printed by the Central Bureau of Standards of the Ministry of Economic Affairs and Consumer Cooperatives. Types of abrasive particles. Solid content (wt.%) Additives and their content (wt.%). PH time to pass through the dense layer (sec.) Copper; 0 Sweat body speed Z peak clock) 1 Colloidal silica 2 Benzotriazole (0.1%) 3-4 can't be worn through before m 2 Colloidal silica 2 Benzotriazole (0.1%) HN03 (0.2 ° / 〇) 3-4 Can't wear through pain ) No. 3 Colloidal silica 2 Benzotriazole (0.1%) H3PO4 (0.2%) 3-4 Unable to wear through the injection item "4 Colloidal silica 2 Benzotriazole (0.1%) H2SO4 (0.2%) 3-4 Can't wear through again 5 Colloidal silica 2 Benzotriazole (0.1%) HC1 (0.2%) 3-4 15 Page 1 2730 j 1 6 Colloidal silica 2 Benzotriazole (0.1% ) NH4CI (0.2%) 3-4 25 1 1693 7 Alumina 2 Benzotriazole (0.1%) HC1 (0.2%) 3-4 10 4270 Order I 8 Colloidal silica 2 Benzotriazole (0.1%) HC1 (0.2%) 5-6 20 1 1872 1 I 9 Colloidal silica 2 Benzotriazole (0.1%) HC1 (0.2%) 2-3 10 5325 1 10 Colloidal silica 2 Benzotriazole (0.1 %) HC1 (0.05%) 3-4 15 4022 ^ 11 colloidal silica 2 benzotriazole (0.1%) dimethylamine hydrochloride HN (CH3) 2-HC1 (0.1%) 3-4 20 1 1677 1 1 I 12 Colloidal silica 2 Benzotriazole (0_1%) Tetramethylammonium gas N (CH3) 4 + Cr (0.1%) 3-4 25 1 1 1260 | 13 Colloidal silica 2 Benzotriazole ( 0.1%) Hydrogenated carbazide H2NNH-C (= 0) NH2 * HC1 (0.1%) 3-4 25 1 1 1932 | 1 _L Description of the invention (1Q) Table 1 This paper size applies to Chinese National Standard (CNS) A4 Specifications (210X297 mm) 581804 A7 B7 11. V. Description of the invention (Note: (1) Known from Examples 1-5, after adding hydrogen chloride, you can wear through the dense layer on the surface of the copper wafer. (2) From Example 5- It is known that chloride ions play an important role. (3) According to Examples 5 and 7, the addition of chloride ions is suitable for polishing liquids using colloidal silica and alumina as abrasive particles. (4) From Examples 7-13 It is known that chloride ion is the main substance that wears through the dense layer on the surface of copper. (Please read the precautions on the back before filling this page)

: 1T Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs -14-This paper size applies to China National Standard (CNS) Α4 specification (210 × 297 mm)

Claims (1)

581804 A8 / Leading Private I 5 Tiger Special Application for 5 Youth Cases-She Increased Nose W ----- ------------, plus iiiiP Scope Replacement Book (January 1993 Replacement of Surplus: Application for Patent Scope month, tr • A chemical mechanical polishing slurry composition, which contains 70-99.5 wt% water-based media, 0.1-25 wt% of abrasive particles; 0.001 wt.% Triazole compound as a corrosion inhibitor, 〇〇〇1 · 10% by weight of a water-soluble chloride ion source, and ○ _ 5% by weight of an oxidizing agent. 2 · According to the patent application of the chemical mechanical polishing liquid composition 'where the abrasive particles It is selected from Si02, Al2O3, ZK) 2, Ce02, SiC, Fe2O3, Ti02, Si3N4, or a mixture thereof. 3. The chemical mechanical polishing slurry composition 'according to item 丨 of the patent application scope, which contains 0.5-15% by weight of abrasive particles. 4. The chemical-mechanical polishing liquid composition according to item 3 of the patent application scope, which contains 0.5 10.0% by weight of abrasive particles. 5. The chemical-mechanical polishing polymer composition according to item 丨 of the patent application scope, which comprises a source of chloride ion of 0.001-0.5% by weight. 6. The chemical-mechanical polishing slurry composition 'according to item 5 of the patent application scope, which comprises a source of chloride ion in an amount of 0.02 to 1.1% by weight. 7. The chemical-mechanical polishing polymer composition according to the scope of application for patent (i), wherein the triazole compound is selected from benzotriazole and cyanuric acid (1,3,5-triaZine-2,4,6-td 〇l), 1,2,3-triazole, 3-amino], 2, [triazole, 3-nitro-1,2,4-triazole, Popeder (Similar to fluorene), benzo Triazole-5-carboxylic acid, 3-amino_1,2,4-triazole. 5-carboxylic acid, hydroxybenzotriazole, and nitrobenzotriazole. 8. The chemical mechanical polishing slurry composition according to item 7 of the patent application, wherein the triazole compound is benzotriazole. 9. The chemical mechanical polishing slurry composition according to item 1 of the scope of the patent application, wherein the oxidant is selected from the group consisting of h202, Fe (N03h, κκ > 3, CH3C000H, and KMn〇4 0 ------ O: \ 71 \ 71621-9im · > η ζ-1-This paper size is applicable to Chinese National Standard (CNS) A4 specification (210 X 297 mm) 8 8 8 8 ABCD 581804 6. Patent application scope 1. According to patent application scope The chemical mechanical polishing slurry composition of item 9, wherein the oxidant is H202. 1 1. The chemical mechanical polishing slurry composition according to item 1 of the patent application scope, wherein the water-soluble chloride ion source is selected from the group consisting of hydrogen chloride, chlorine Ammonium chloride, dimethylamine hydrochloride, tetramethylammonium chloride, and hemicarbazine hydrochloride, etc. O: \ 71 \ 71621-93012Q.DOC 5 _ △ This paper size applies to Chinese National Standards (CNS) A4 size (210 X 297 mm)