KR20100083492A - Slurry composition for chemical mechanical polishing of metal film - Google Patents

Abstract

PURPOSE: A chemical mechanical polishing slurry composition for a metal film is provided to offer slurry without the surface defect, and to prevent the generating of a scratch with the improved slurry dispersion stability. CONSTITUTION: A chemical mechanical polishing slurry composition for a metal film contains an abrasive, an organic compound having a carboxyl group, and amine or amino alcohol as a polishing speed enhancer. The abrasive is zeolite, fumed silica, colloid silica, alumina, ceria, zirconium oxide, titanium oxide, or their compound. The polishing speed enhancer is selected from the group consisting of diethylamine, monoethanolamine, diethanolamine, triethanolammine, hexylamine, propylamine, 3- aminopropanol, or their mixture.

Description

Slurry composition for chemical mechanical polishing of metal film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slurry composition for chemical mechanical polishing of a metal film, and more particularly, to planarization of aluminum materials such as contact or interconnection between devices for supplying power and forming pads for wiring. For the chemical mechanical polishing slurry of the required process.

As semiconductor devices become more integrated and higher in performance, metallization layers increase, and strict DOF (depth of focus) and fine design rules are applied to the chemical mechanical polishing (CMP) process, which is a planarization process. Increasingly, the multilayer wiring forming process is applied to various processes such as planarization of an interlayer insulating film, metal plug formation, and damascene wiring formation.

Tungsten, aluminum, copper and the like are increasingly used as wiring materials for semiconductor devices. Metal wiring using aluminum, which has the next lowest resistance after copper, has the advantage of being able to use existing equipment, which reduces manufacturing costs and has excellent mass production. In addition, a dual damascene process may be applied to the aluminum wiring process, and problems caused by electro-migration may be solved by using an alloy containing copper or silicon.

Metal film polishing slurry generally requires a high polishing rate for the metal film to be removed, and may require a slurry in which the selectivity between the metal film and the insulating film can be freely adjusted according to the process conditions and the user's request. In addition, among the wiring materials, aluminum is a metal of relatively low hardness, which is likely to cause scratches caused by large abrasive particles, and is also susceptible to stress. This may cause high quality of the polishing surface.

On the other hand, the aluminum film polishing slurry is disclosed in US Patent No. 5,783,489, not only the amount of the oxidant is excessively used, but also defects such as scratches may occur when removing the oxidized metal film by the use of the excessive oxidant. The slurry for aluminum film CMP disclosed in Korean Patent Laid-Open Publication No. 2005-0034381 is likely to cause problems in reducing the polishing rate of the metal film and storage stability of the slurry due to the cationic additive added to improve the polishing selectivity of the aluminum film over the insulating film. high.

An object of the present invention is to provide a slurry composition for metal film CMP having a high polishing rate of the metal film and having a high selectivity between the metal film and the silicon oxide film.

Another object of the present invention is to provide a slurry composition for CMP suitable for use in a metal film CMP containing a metal having a low hardness such as aluminum, since it is possible to effectively manufacture a mirror metal film without surface scratches.

Still another object of the present invention is to provide a chemical mechanical polishing method capable of selectively removing a metal film in a CMP process for a substrate containing a metal film using the slurry composition for metal film CMP.

In order to solve the above problems, the inventors of the present invention have studied the slurry for polishing a metal film, and as a result, when the organic material having one carboxyl group is contained, the slurry stability is improved, the polishing rate is high, and a high selection between the metal film and the silicon oxide film is performed. It has been found that it is possible to obtain a ratio, and to effectively produce a mirror-surface metal film without surface scratches, and when it contains an amine or amino alcohol, it is surprisingly found that the polishing rate for the metal film is significantly improved, thereby completing the present invention. Was done.

The present invention relates to a chemical mechanical polishing slurry composition for performing a metal film polishing process, and more particularly, to a metal film CMP slurry containing an amine or an amino alcohol as an abrasive, an organic material having one carboxyl group, and a polishing rate improving agent. To provide a composition.

The present invention also provides a chemical mechanical polishing method for a metal film-containing substrate, using the slurry composition for metal film CMP. The metal film-containing substrate may be formed of a metal film to be polished, and may further include a silicon oxide film, a silicon nitride film, a metal oxide film, or a metal nitride film in addition to the metal film.

The composition for CMP according to the present invention can achieve a high polishing rate and a polishing selectivity for a metal film without using an oxidizing agent, can suppress dishing and erosion, and slurry dispersion stability Since this is very excellent, it is applied to a metal film having a low hardness, such as aluminum, and has an effect of not causing defects such as scratches.

Hereinafter, the present invention will be described in more detail.

The slurry composition for metal film CMP according to the present invention is a composition containing an abrasive, an organic substance having one carboxyl group, an amine or amino alcohol as a polishing rate enhancer, and deionized water, and may further contain a pH adjusting agent for adjusting pH. have.

The abrasive contained in the slurry according to the present invention serves to control the polishing rate of the insulating film such as a metal film, an oxide film. As the amount of the abrasive increases, the polishing rate of the metal film increases. As the abrasive, zeolite, fumed silica, colloidal silica, alumina, ceria, zirconium oxide, titanium oxide and mixtures thereof can be used. Preferred abrasives are colloidal silica, alumina and zeolite, more preferred abrasives are alumina, and the content is preferably from 0.1 to 25% by weight, more preferably from 0.1 to 10% by weight. The lower the content, the better the dispersibility and the scratch, but the lower the 0.1% by weight, the lower the polishing rate of the metal film, more than 25% by weight is difficult to expect the improvement of the dispersibility and polishing rate.

The organic material having one carboxyl group according to the present invention enables the polishing of a metal film without an oxidizing agent, and has an effect of improving the dispersibility of the abrasive, thereby significantly reducing the surface defects such as scratches caused by mechanical friction. have. On the other hand, in the case of polyhydric carboxylic acid, the dispersibility of the abrasive is deteriorated to generate scratches.

The organic material having one carboxyl group is acetic acid, lysine, serine, threonine, valine, acrylic acid, butyric acid, aminobutyric acid, isobutyric acid, methacrylic acid, glycolic acid, glycoic acid, gluconic acid, propionic acid, alanine, glycine, arginine or its It may be used alone or in combination as a derivative, the content is preferably 0.0001 to 10% by weight, particularly preferably 0.1 to 5% by weight. If the content is less than 0.0001% by weight, the effect of improving the dispersibility of the abrasive is insignificant. If the content is more than 10% by weight, the effect of increasing the content is insignificant, which is disadvantageous in terms of economy. However, the organic substance having one carboxy group is not limited to those described in the text.

The polishing rate improving agent is selected from a primary, secondary or tertiary amine compound having an amine group as a functional group or aminoalcohol, and an amine or aminoalcohol having 2 to 10 carbon atoms is preferable, and specific compounds include diethylamine and monoethanol. Amines, diethanolamine, triethanolamine, hexylamine, propylamine, 3-aminopropanol and the like. The content of the polishing rate improving agent is preferably 0.0001 to 5% by weight based on the total weight of the composition, and more preferably 0.001 to 2% by weight when considering slurry dispersion stability. When the content is lower than 0.0001% by weight, the polishing rate improvement effect is insignificant, and the dispersion stability of the slurry may be lowered at 5% by weight or more.

The composition of the slurry according to the present invention may further use a defect preventive agent to reduce surface defects, and the defect preventive agent may be 1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 5-methyl-1,2,3,4-tetrazole, 1,2,3-triazole, 4-amino-1,2,3-triazole, 4,5-diamino-1,2,3- Triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, benzotriazole, 5,6-dimethyl -1,2,3-benzotriazole (DBTA), 1- (1,2-dicarboxyethyl) benzotriazole (DCEBTA), 1- [N, N-bis (hydroxyethyl) aminomethyl] benzotria Sol (HEABTA), 1- (hydroxymethyl) benzotriazole (HMBTA), triazole-3-carboxylic acid, benzotriazole-5-carboxylic acid, 1-alkyl-5-aminotetrazole, 5-hydroxy-tetra Sol, 1-alkyl-5-hydroxy-tetrazole, tetrazol-5thiol, imidazole and diethylethylenediamine, tetramethylethylenediamine, diethylenetriamine, pentamethyldiethylenet Amine can be 2-hydroxyethyl ethylene diamine in tree acid, ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid and salts thereof used alone or in combination. The defect preventing agent may be mixed or used alone, and the amount added is preferably 0.0001% to 1% by weight, more preferably 0.05% to 0.5% based on the total weight of the composition. If the content is more than 1% by weight can lead to a reduction in polishing rate, less than 0.0001% by weight is difficult to expect the effect of the additive.

The slurry composition according to the present invention can secure a high polishing rate for the metal film and a high polishing selectivity for the insulating film even without an oxidizing agent. In addition, hydrogen peroxide, periodate, potassium iodide, ammonium persulfate, potassium ferricyanide, potassium bromide, vanadium trioxide, hypochlorite, sodium hypochlorite, and ferric nitrate can be used to increase the polishing rate of titanium or titanium nitride films, which are diffusion barrier films. It is also possible to add commonly used oxidants such as. The oxidizing agent content is preferably 0.01 to 10% by weight based on the total weight of the composition. When the content is less than 0.01% by weight, the effect of increasing the polishing rate of the titanium-based film is insignificant, and the content is too high exceeding 10% by weight. This is because the stability of the slurry composition may decrease.

The slurry composition of the present invention need not be limited to a pH range. However, in order to secure additional slurry stability, the pH is preferably 2 to 8, more preferably 2 to 5, and any pH adjusting agent may be used as long as the pH can be obtained as the pH adjusting agent. It is desirable to use materials that do not contain ions, such as sodium (Na) ions, which may affect the properties of the device at the time. Usable pH adjusting agents include, but are not limited to, nitric acid, potassium hydroxide (KOH), and the like. If the pH range is lower than 2, it may cause corrosion of equipment and the like.

The present invention provides a chemical mechanical polishing method for a metal film-containing substrate, wherein the chemical mechanical polishing is performed using the slurry composition for metal film CMP. Substrates for metal film-containing substrates include aluminum, copper, tungsten, titanium, gallium, silver, gold, platinum, tantalum, titanium, ruthenium, palladium, nickel, cobalt, phase change metals (Ge _X Sb _y Te _z ), hafnium, etc. It may be made of one or more metal films selected from, and may further comprise a silicon oxide film, a silicon nitride film, a metal oxide film or a metal nitride film in addition to the metal film. The metal film may contain aluminum, and may further contain other metal components such as titanium in addition to aluminum, may be an alloy of aluminum and other metal components, and may be formed of a single layer or multiple layers.

The slurry composition according to the invention may additionally comprise a surfactant. The surfactant has a function of lowering the contact angle of the surface to be polished to promote uniform polishing. As an anionic surfactant used, what was selected from the following groups is preferable.

Examples thereof include carboxylate, sulfonate, sulfuric acid ester salt and phosphate ester salt. Examples of the carboxylate salt include soap, N-acylamino acid salt, polyoxyethylene or polyoxypropylene alkyl ether carboxylate, and acylation. Peptides; Alkyl sulfonates, sulfosuccinates, α-olefin sulfonates, N-acyl sulfonates as sulfonates; As sulfuric acid ester salts, sulfated oil, alkyl sulfate, alkyl ether sulfate, polyoxyethylene or polyoxypropylene alkyl allyl ether sulfate, alkylamide sulfate; phosphoric acid ester salts include alkyl phosphate, polyoxyethylene or polyoxypropylene alkyl allyl ether phosphate Can be. The amount of the anionic surfactant added is preferably 0.0001% by weight to 5% by weight when used for polishing as a total amount.

In the present invention, in addition to the anionic surfactant, it is also possible to use other surfactant together. As another surfactant which can be used together, what is shown below is mentioned.

As a cationic surfactant, For example, aliphatic amine salt, aliphatic quaternary ammonium salt, benzalkonium chloride, benzetonium chloride, pyridinium salt, imidazolinium salt; Examples of amphoteric surfactants include carboxybetaine, aminocarboxylate, imidazolinium betaine, lecithin, and alkylamine oxides.

As a nonionic surfactant, an ether type, an ether ester type, ester type, a nitrogen containing type is mentioned, for example, As an ether type, polyoxyethylene alkyl and alkylphenyl ether, alkyl allyl formaldehyde condensation polyoxyethylene ether, poly And oxyethylene polyoxypropylene block polymers and polyoxyethylene polyoxypropylene alkyl ethers. Examples of the ether ester type include polyoxyethylene ethers of glycerin esters, polyoxyethylene ethers of sorbitan esters, and polyoxyethylene ethers of sorbitol esters. As ester type, polyethylene glycol fatty acid ester, glycerin ester, polyglycerol ester, sorbitan ester, propylene glycol ester, sucrose ester, nitrogen containing type fatty acid alkanolamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamide, etc. And the like. And fluorine-based surfactants.

The hydrophilic polymer has a function of lowering the contact angle of the surface to be polished like the surfactant, and has a function of promoting uniform polishing. As the hydrophilic polymer to be used, one selected from the following groups is preferable.

As a hydrophilic polymer, For example, ester, such as glycerol ester, sorbitan ester, methoxy acetic acid, ethoxy acetic acid, 3-ethoxy propionic acid, and alanine ethyl ester; Polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, polyethylene glycol alkenyl ether, alkyl polyethylene glycol, alkyl polyethylene glycol alkyl ether, alkyl polyethylene glycol alkenyl ether, alkenyl polyethylene glycol, alkenyl polyethylene glycol alkyl Ether, alkenyl polyethylene glycol alkenyl ether, polypropylene glycol alkyl ether, polypropylene glycol alkenyl ether, alkyl polypropylene glycol, alkyl polypropylene glycol alkyl ether, alkyl polypropylene glycol alkenyl ether, alkenyl polypropylene glycol, al Ethers such as kenyl polypropylene glycol alkyl ether and alkenyl polypropylene glycol alkenyl ether; Polysaccharides, such as alginic acid, pectinic acid, carboxymethylcellulose, curdlan, and pullulan, etc. can be used individually or in mixture.

The present invention relates to a chemical mechanical polishing slurry composition for performing a metal film polishing process in a semiconductor manufacturing process, the slurry composition according to the present invention has a high selectivity even without an oxidizing agent using an organic material having one carboxyl group, It is possible to provide a slurry free, and it is possible to achieve a higher polishing rate, including a polishing rate improver and a defect preventing agent. The slurry of the present invention can improve the yield through the removal of surface defects after polishing, and can further reduce the process time by implementing a high aluminum polishing rate. In addition, the slurry composition according to the present invention has an advantage of reducing defects such as scratches due to excellent aging stability and dispersion stability.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples do not limit the scope of the present invention.

[Example]

The aluminum wafer used for polishing was a specimen wafer on which 10000 μs of aluminum was deposited by PVD, and the silicon oxide film was used on a specimen wafer on which 10000 μs PETEOS thin film was deposited. The polishing equipment used was Poli400 manufactured by G & P Technology. The polishing pad was subjected to a polishing test using an IC1000 pad manufactured by Rohm & Haas. The polishing conditions were Table / Head speed of 93/87 rpm, polishing pressure of 300 g / cm2, retainer ring pressure of 360 g / cm2, The slurry feed flow rate was 200 ml / min and the polishing time was 60 seconds. The aluminum film thickness was calculated by measuring the sheet resistance using an AIT four probe surface resistance measuring instrument (Four Point Probe). PETEOS thin film thickness was measured by Spectra Thick 4000 of K-MAC.

Surface scratches were identified by optical microscopy (magnification: 1000 times), and the surface conditions were classified into good (○), normal (△), and poor (X) as shown in FIG. The results are shown in Table 1.

Slurry dispersion stability was confirmed by measuring the transparency of the supernatant and the lower layer and the presence of particles sinking in the lower layer after 7 days after the slurry was prepared. The transparency of the supernatant and the lower layer was the same or similar, and the lower layer When the particles did not sink in the liquid part, it was shown as good (○), and when the supernatant liquid became transparent or when the particles sank in the lower part liquid part, it was indicated as bad (X).

Example 1

The organic material having 2% by weight of alumina and one carboxyl group as a functional group was mixed in the composition shown in Table 1 below, and the pH was adjusted to 3 to 5 by adding nitric acid and potassium hydroxide.

Table 1 shows the results of evaluating the polishing rate for the slurry composition. As shown in Table 1, the slurry composition has a high removal rate with respect to the metal film and a low silicon oxide film (PETEOS) polishing rate, so that the slurry composition is suitable for use as the metal film polishing composition.

As shown in the results of Table 1 below, the addition of an organic material having one carboxyl group as a functional group increased the polishing rate of the metal film, and the composition having two or three carboxyl groups as a functional group had very poor slurry dispersion stability. Scratch occurred due to dispersibility. From the above results, it was confirmed that the slurry composition according to the present invention has a high polishing rate of the metal film, a good surface state during polishing, and a good dispersion stability of the slurry.

TABLE 1

[Example 2]

Except for changing the type of the abrasive in the slurry composition of Preparation Example 3, a slit was prepared in the same manner and the polishing rate of the metal film was measured.

TABLE 2

As shown in Table 2, except for fumed silica and ceria, the polishing rate of the metal film was realized.

Example 3

The polishing rate improver was further added to the slurry composition of Preparation Example 3 to compare the polishing rate improving effect and the results are shown in Table 3 below.

[Table 3]

As shown in the results of Table 3, the metal film upon addition of a compound having an amine or an amino alcohol as a functional group And select the polishing rate between the oxide film It was found that the additives of the polymer type resulted in a decrease in the polishing rate.

1 is an optical microscope photograph of the surface state after aluminum polishing.

Claims (13)

abrasive; Organic material having one carboxyl group; A slurry composition for chemical mechanical polishing of a metal film containing amine or amino alcohol as a polishing rate improving agent. The method of claim 1, The abrasive is one or a mixture of zeolite, fumed silica, colloidal silica, alumina, ceria, zirconium oxide, titanium oxide and the content is 0.1 to 25% by weight relative to the total weight of the composition slurry composition for chemical mechanical polishing of a metal film. 3. The method of claim 2, The polishing agent is a slurry composition for chemical mechanical polishing of an alumina or colloidal silica metal film. The method of claim 1, The organic material having one carboxyl group is acetic acid, lysine, serine, threonine, valine, acrylic acid, butyric acid, aminobutyric acid, isobutyric acid, methacrylic acid, glycolic acid, glycoic acid, gluconic acid, propionic acid, alanine, glycine, arginine or its Slurry composition for chemical mechanical polishing of a metal film is at least one selected from derivatives and the content is 0.0001 to 10% by weight based on the total weight of the composition. The method of claim 1, The polishing rate improving agent is selected from diethylamine, monoethanolamine, diethanolamine, triethanolamine, hexylamine, propylamine, 3-aminopropanol or a mixture thereof and the content is 0.0001 to 5% by weight based on the total weight of the composition. Slurry composition for chemical mechanical polishing of membranes. The method of claim 5, The polishing rate enhancer is a slurry composition for chemical mechanical polishing of a metal film is 0.001 to 2% by weight based on the total weight of the slurry. The method of claim 1, The composition is a slurry composition for chemical mechanical polishing of a metal film further comprises a defect preventing agent to be 0.0001 to 1% by weight based on the total weight of the composition. The method of claim 7, wherein The defect avoidant is 1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 5-methyl-1,2,3,4-tetrazole, 1,2,3 -Triazole, 4-amino-1,2,3-triazole, 4,5-diamino-1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2, 4-triazole, 3,5-diamino-1,2,4-triazole, benzotriazole, 5,6-dimethyl-1,2,3-benzotriazole (DBTA), 1- (1,2 -Dicarboxyethyl) benzotriazole (DCEBTA), 1- [N, N-bis (hydroxyethyl) aminomethyl] benzotriazole (HEABTA), 1- (hydroxymethyl) benzotriazole (HMBTA), Triazole-3-carboxylic acid, benzotriazole-5-carboxylic acid, 1-alkyl-5-aminotetrazole, 5-hydroxy-tetrazole, 1-alkyl-5-hydroxy-tetrazole, tetrazol-5thiol , Imidazole and diethylethylenediamine, tetramethylethylenediamine, diethylenetriamine, pentamethyldiethylenetriamine, 2-hydroxyethylethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, diethylene Pentaacetic acid and at least one element selected from a salt content of from 0.0001 to 1% by weight of the metal film is a chemical mechanical polishing slurry composition relative to the composition total weight. The method of claim 1, The composition is a slurry composition for chemical mechanical polishing of a metal film further comprises an oxidizing agent to 0.01 to 10% by weight relative to the total weight of the composition. The method of claim 9, The oxidizing agent is selected from hydrogen peroxide, periodioic acid, potassium iodide, ammonium persulfate, potassium ferricyanide, potassium bromide, vanadium trioxide, hypochlorous acid, sodium hypochlorite, ferric nitrate or mixtures thereof. A chemical mechanical polishing slurry composition of a metal film of 0.01 to 10% by weight based on the weight. The method of claim 1, The composition is a slurry composition for chemical mechanical polishing of a metal film further comprises a hydrophilic polymer, a surfactant and a mixture thereof so as to be 0.0001 to 5% by weight relative to the total weight of the composition. Aluminum, copper, tungsten, titanium, gallium, silver, gold, platinum, tantalum, titanium, ruthenium, nickel, cobalt, phase conversion, characterized by using the slurry composition of any one of claims 1-11. A method of chemical mechanical polishing of a substrate comprising at least one metal film selected from metal (Ge _X Sb _y Te _z ), palladium, and hafnium, or further comprising a silicon oxide film, a silicon nitride film, a metal oxide film, or a metal nitride film in addition to the metal film. The method of claim 12, And the substrate contains aluminum.

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