KR102578037B1 - Positive polishing slurry composition - Google Patents

Abstract

The present invention relates to a positive polishing slurry composition, and more specifically, to an additive solution containing a cationic compound, an organic acid, and an additive compound; and a polishing liquid containing abrasive particles, wherein the added compound contains an aromatic ring, a hydroxy group, a carboxyl group, or both, and after polishing a wafer containing an oxide film and a nitride film or an oxide film and a polysilicon film, the space size It relates to a positive polishing slurry composition in which the amount of dishing of a wafer having a pattern of 0.1 mm to 5 mm is 1000 Å or less.

Description

Positive polishing slurry composition {Positive polishing slurry composition}

The present invention relates to positive polishing slurry compositions.

Chemical mechanical polishing (CMP) is a semiconductor processing technology in which mechanical processing by an abrasive present between a pressurized wafer and a polishing pad and chemical etching by the chemical components of a slurry occur simultaneously. It is a semiconductor processing technology in which submicron scale Wide-area planarization technology has become an essential process in the manufacture of semiconductor chips. Among the types of slurry compositions, the oxide slurry composition is used to polish the silicon oxide layer used in the interlayer insulation film and STI (Shallow Trench Isolation) process. The ceria slurry composition using ceria as abrasive particles is used to polish the silicon oxide layer in the STI process. It is widely used for polishing, and in this case, a silicon nitride layer is mainly used as a polishing stop layer. Generally, in order to improve the polishing rate selectivity of the oxide layer to the nitride layer, a certain chemical additive is added to the ceria slurry composition. The additive is based on a polymer containing a carboxyl group and provides selectivity and flatness functions. It was optimized for a negative slurry composition with a negative charge, and when used in a positive slurry composition with a positive charge, it coagulated and reacted with the slurry composition, resulting in a decrease in removal rate, selectivity function, and flatness performance. Positive slurry can realize a high polishing rate through high reaction with the wafer and pad, but has the disadvantage of being weak in terms of selectivity and flatness. Accordingly, there is a need to develop an additive solution that increases selectivity and flatness while maintaining a high polishing rate when used with a positive slurry composition.

The present invention is intended to solve the above-mentioned problems, and the purpose of the present invention is to provide a positive polishing slurry composition that maintains excellent polishing speed and selectivity and is excellent in improving flatness, dishing, scratches, and defects.

In addition, a polishing slurry composition capable of implementing low dishing in a large pattern area (space size of 0.1 mm or more) of a cell type pattern is provided.

However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

A positive polishing slurry composition according to an embodiment of the present invention includes an additive solution containing a cationic compound, an organic acid, and an additive compound; and a polishing liquid containing abrasive particles, wherein the added compound contains an aromatic ring, a hydroxy group, a carboxyl group, or both, and after polishing a wafer containing an oxide film and a nitride film or an oxide film and a polysilicon film, the space size The amount of dishing of a wafer having a pattern of 0.1 mm to 5 mm is 1000 Å or less.

According to one aspect, at least one carbon of the aromatic ring of the addition compound may be substituted with oxygen, nitrogen, or both.

According to one aspect, the addition compound may further include an amino group.

According to one aspect, the added compound is aziridine-2-carboxylic acid, azetidine-2-carboxylic acid, and azetidine-3-carboxylic acid. Azetidine-3-carboxylic acid, Proline, pyrrolidine-3-carboxylic acid, piperidine-2-carboxylic acid ), piperidine-3-carboxylic acid, piperidine-4-carboxylic acid, azepane-2 -carboxylic acid), azepane-3-carboxylic acid, azepane-4-carboxylic acid, 2H-pyrrole-2-carboxylic acid (2H) -pyrrole-2-carboxylic acid, 3H-pyrrole-3-carboxylic acid, Proline, Phenylalanine, Tryptophan, Quinolinic acid , anthranilic acid, picolinic acid, nicotinic acid, isonicotinic acid, benzoic acid, phenylacetic acid, naphthoic acid, only Mandelic acid, fusaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyridinecarboxylic acid, glucose, D-glucosamine D-Glucosamine hydrochloride, D-(+)-Glucose monohydrate, N-Acetyl-D-glucosamine and D-(-) -It may contain at least one selected from the group consisting of ribose (D-(-)-Ribose).

According to one aspect, the additive compound may be included in an amount of 0.01% by weight to 0.5% by weight in the positive polishing slurry composition.

According to one aspect, the cationic compound may include at least one selected from the group consisting of amino acids, polymer polysaccharides to which glucosamine compounds are bound, and amine group-containing polymers.

According to one aspect, the organic acids include pimelic acid, malic acid, malonic acid, maleic acid, acetic acid, adipic acid, oxalic acid, succinic acid, tartaric acid, citric acid, lactic acid, glutaric acid, glycolic acid, formic acid, fumaric acid, propionic acid, Butyric acid, hydroxybutyric acid, aspartic acid, itaconic acid, tricarbal acid, suberic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, picolinic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fuzaric acid, It may contain at least one selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and pyridinecarboxylic acid.

According to one aspect, the cationic compound and the organic acid may each be included in an amount of 0.001% to 5% by weight in the positive polishing slurry composition.

According to one aspect, the positive polishing slurry composition may further include a pH adjuster.

According to one aspect, the pH adjuster includes nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, hydrobromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, and propionic acid. , fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, and an acidic substance containing at least one selected from the group consisting of salts thereof. ; and selected from the group consisting of ammonia, 2-amino-2-methyl-1-propanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate and imidazole. It may contain at least one selected from the group consisting of an alkaline substance containing at least one of the following.

According to one aspect, the pH of the positive polishing slurry composition may be 2 to 7.

According to one aspect, the abrasive particles may be ceria dispersed with positive charges.

According to one aspect, the abrasive particles may include primary particles of 5 nm to 150 nm and secondary particles of 30 nm to 300 nm.

According to one aspect, the surface zeta potential of the positive polishing slurry composition may be +5 mV to +70 mV.

According to one aspect, an oxide film and a nitride film on a blanket wafer using the positive polishing slurry composition; Or, when polishing a wafer including an oxide film and a polysilicon film, the polishing rate of the oxide film may be 1,000 Å/min to 4,000 Å/min, and the polishing rate of the nitride film or the polysilicon film may be 50 Å/min or less. there is.

The positive polishing slurry composition according to the present invention contains an additive liquid containing a cationic compound, an organic acid, and an additive compound, and thus has excellent dispersion stability, maintains excellent polishing speed and selectivity, and has excellent resistance to flatness, dishing, scratches, A positive polishing slurry composition excellent for improving defects can be provided.

In addition, a polishing slurry composition capable of realizing low dishing in a large pattern area (space size of 0.1 mm or more) of a cell type pattern by including the above additive compound containing an aromatic ring, a hydroxy group, a carboxyl group, or both. can be provided.

Figure 1 is a view showing the cross-sectional structure of the wafer after pattern evaluation of the wafer using the positive polishing slurry composition according to Examples 1 to 15 and Comparative Examples 1 to 12 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In describing the present invention, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms used in this specification are terms used to appropriately express preferred embodiments of the present invention, and may vary depending on the intention of the user or operator or the customs of the field to which the present invention belongs. Therefore, definitions of these terms should be made based on the content throughout this specification. The same reference numerals in each drawing indicate the same members.

Throughout the specification, when a member is said to be located “on” another member, this includes not only cases where a member is in contact with another member, but also cases where another member exists between the two members.

Throughout the specification, when a part “includes” a certain component, this does not mean excluding other components, but rather means that it can further include other components.

Hereinafter, the positive polishing slurry composition of the present invention will be described in detail with reference to examples and drawings. However, the present invention is not limited to these examples and drawings.

A positive polishing slurry composition according to an embodiment of the present invention includes an additive solution containing a cationic compound, an organic acid, and an additive compound; and a polishing liquid containing abrasive particles, wherein the added compound contains an aromatic ring, a hydroxy group, a carboxyl group, or both, and after polishing a wafer containing an oxide film and a nitride film or an oxide film and a polysilicon film, the space size The amount of dishing of a wafer having a pattern of 0.1 mm to 5 mm is 1000 Å or less.

The positive polishing slurry composition according to the present invention contains an additive liquid containing a cationic compound, an organic acid, and an additive compound, and thus has excellent dispersion stability, maintains excellent polishing speed and selectivity, and has excellent resistance to flatness, dishing, scratches, A positive polishing slurry composition excellent for improving defects can be provided.

In addition, a polishing slurry composition capable of realizing low dishing in a large pattern area (space size of 0.1 mm or more) of a cell type pattern by including the above additive compound containing an aromatic ring, a hydroxy group, a carboxyl group, or both. can be provided.

In one embodiment of the present invention, the additive liquid is added to the polishing slurry composition in addition to water to adjust the polishing properties such as polishing speed and polishing selectivity, the dispersibility of the abrasive particles, and the properties of the abrasive particles such as storage stability. means a substance that becomes

In the case of conventional slurry composition additives, selectivity and flatness functions are generally provided based on a polymer containing a carboxyl group, which is optimized for negative slurries. When a conventional slurry composition additive is used in a positive slurry composition, problems arise such as a significant decrease in polishing rate, selectivity, and flatness due to coagulation and reaction with the slurry composition, and the big pattern area of the cell type pattern occurs. There was a problem that low dishing could not be implemented in (space size 0.1 mm or more).

On the other hand, when the additive solution containing the cationic compound, organic acid, and additive compound of the present invention is applied to a positive slurry, high polishing rate, selectivity, and flatness can be provided, and the oxide film and nitride film or the oxide film and polysilicon After polishing the wafer including the film, the amount of dishing of the wafer having a pattern with a space size of 0.1 mm to 5 mm is realized to be 1000 Å or less. this is. This is because added compounds containing an aromatic ring, a hydroxy group, a carboxyl group, or both cause selective adsorption (steric adsorption) of SiN in a large space area (big area).

According to one aspect, at least one carbon of the aromatic ring of the addition compound may be substituted with oxygen, nitrogen, or both.

For example, the aromatic ring in which at least one carbon is substituted with oxygen, nitrogen, or both is aziridine, azetidine, pyrrolidine, piperidine, azepane, pyridine, pyrrole, oxirane, oxetane, tetra It may contain at least one selected from the group consisting of hydrofuran, tetrahydro-2H-pyran, oxepane, 1,3-oxazetidine, oxazolidine, oxazole, and morpholine.

That is, the addition compound according to the present invention may include an aromatic ring in which at least one carbon is substituted with oxygen, nitrogen, or both, and a hydroxy group, a carboxyl group, or both.

According to one aspect, the addition compound may further include an amino group. That is, the addition compound according to the present invention may contain an aromatic ring, an amino group, a hydroxy group, a carboxyl group, or both.

According to one aspect, the added compound is aziridine-2-carboxylic acid, azetidine-2-carboxylic acid, and azetidine-3-carboxylic acid. Azetidine-3-carboxylic acid, pyrrolidine-3-carboxylic acid, piperidine-2-carboxylic acid, piperidine -3-carboxylic acid, piperidine-4-carboxylic acid, azepane-2-carboxylic acid, Azepane-3-carboxylic acid, azepane-4-carboxylic acid, 2H-pyrrole-2-carboxylic acid carboxylic acid, 3H-pyrrole-3-carboxylic acid, Proline, Phenylalanine, Tryptophan, Quinolinic acid, anthranilic acid acid), Picolinic acid, nicotinic acid, isonicotinic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, fuzar fusaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyridinecarboxylic acid, Glucose, D-Glucosamine hydrochloride, D-(+)-Glucose monohydrate, N-Acetyl-D- It may include at least one selected from the group consisting of glucosamine) and D-(-)-ribose.

According to one aspect, the additive compound may be included in an amount of 0.01% by weight to 0.5% by weight in the positive polishing slurry composition.

If the additive compound is included in less than 0.01% by weight, a problem of increased dishing may occur, and if the additive compound is included in more than 0.5% by weight, the stability of the slurry composition may be impaired.

According to one aspect, the cationic compound is a compound containing a cationic group or a group that can be ionized into a cationic group in the main chain or side chain.

According to one aspect, the cationic compound may include at least one selected from the group consisting of amino acids, polymer polysaccharides to which glucosamine compounds are bound, and amine group-containing polymers.

The amino acid has the effect of improving the dispersibility of the abrasive particles and further improving the polishing speed of the insulating film. The amino acids include, for example, arginine, lysine, histidine, aspartic acid, glutamic acid, asparagine, glutamine, tyrosine, serine, cysteine, threonine, glycine, alanine, β-alanine, proline, tryptophan, methionine, phenylalanine, valine, leucine. And it may include at least one selected from the group consisting of isoleucine.

The polymer polysaccharides to which the glucosamine compounds are bound are chitin, chitosan, chitooligosaccharide, mucopolysaccharide, proteoglycan, heparin, alginic acid, cellulose, hyaluronic acid, carrageenan, β-glucan, and chondroitin sulfate, respectively. ) may include at least one selected from the group consisting of

The glucosamine compound included in the polymer polysaccharide may be glucosamine or a glucosamine derivative, for example, N-acetyl-D-glucosamine, N-methylglucosamine, N-acetylgalactosamine, 2-acetamido-2 -deoxy-β-D-glucose (N-acetylglucosamine), poly(β-(1,4)-glucosamine), poly-N-succinyl β-1-6-glucosamine (PNSG), poly-N-acetyl It may contain at least one selected from the group consisting of β-1-6-glucosamine (PNAG), N-acylglucosamine, glucosamine hydrochloride, and glucosamine oligosaccharide.

The amine group-containing polymer can increase the polishing rate of insulating films such as oxide films and nitride films without worsening flatness, and can suppress the occurrence of dishing, scratches, and defects. The amine group-containing polymer includes, for example, at least one selected from the group consisting of primary amine, secondary amine, tertiary amine, and cationic polymer. It may be.

The primary to tertiary amines include methylamine, ethanolamine, propylamine, butylamine, isopropylamine, monoethanolamine, diethanolamine, triethanolamine, dipropylamine, ethylene diamine, propane diamine, triethylamine, Tributylamine, tetramethylamine, triethylene tetraamine, tetraethylene pentamine, 2-(dimethylamino)ethanol, 2-diethylaminoethanol, 2-dipropylaminoethanol, 2-butylaminoethynol, 2-t -Butylaminoethanol, 2-cycloaminoethanol, 2-amino-2-pentanol, 2-[bis(2-hydroxyethyl)amino]-2-methyl-1-propanol, 2-[bis(2-hyde) Roxyethyl)amino]-2-propanol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, 2-dimethyl amino-2-methyl-1-propanol, 1-Amino-2-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino-1-propanol, 2-dimethylamino-1-propanol, 2-diethylamino-1-propanol, 3-amino-1 -Propanol, 2-amino-1-propanol, 1-amino-2-propanol, 1-amino-pentanol, N-methyldiethanolamine, N-propyldiethanolamine, N-isopropyl diethanolamine, N- (2-methylpropyl)diethanolamine, N-n-butyldiethanolamine, N-t-butylethanolamine, N-cyclohexyldiethanolamine, N,N-bis(2-hydroxypropyl)ethanolamine, and triisopropanol It may contain at least one selected from the group consisting of amines.

The cationic polymer may contain two or more ionized cations in its molecular formula, and preferably may contain two or more cationically activated nitrogens, and the cationic polymer may be in the form of quaternary ammonium. there is. The cationic polymer is poly(diallyldimethyl ammonium chloride); poly[bis(2-chloroethyl)ether-alt-1,3-bis[3-(dimethylamino)propyl]urea ](Poly[bis(2- chloroethyl) ether-alt-1,3-bis[3-(dimethylamino)propyl]urea]); 1,4-dichloro-2-butene and N,N,N',N' -2,2',2''-nitrilotris-ethanol polymer with -tetramethyl-2-butene-1,4-diamine (Ethanol, 2,2',2 '' -nitrilotris-, polymer with 1,4- dichloro-2-butene and N,N,N',N'-tetramethyl-2-butene-1,4-diamine); Hydroxyethyl cellulose dimethyl diallylammonium chloride copolymer ; Copolymer of acrylamide and diallyldimethylammonium chloride; Copolymer of acrylamide and quaternized dimethylammoniumethyl methacrylate; Acrylic acid/diallyldimethylammonium chloride copolymer (Copolymer of acrylic acid and diallyldimethylammonium Chloride); Acrylamide-dimethylaminoethyl methacrylate methyl chloride copolymer; Quaternized hydroxyethyl cellulose; Vinylpyrrolidone/ Copolymer of vinylpyrrolidone and quaternized dimethylaminoethyl methacrylate; Copolymer of vinylpyrrolidone and quaternized vinylimidazole; Copolymer of vinylpyrrolidone and methacrylamidopropyl trimethylammonium; Poly(2-methacryloxyethyltrimethylammonium chloride); Poly(acrylamide 2-methacryloxyethyltrimethyl ammonium chloride); poly[2-(dimethyl amino)ethyl methacrylate)methyl chloride](poly[2-(dimethylaminoethyl methacrylate) methyl chloride]); poly[3-acrylamidopropyl trimethylammonium chloride](poly[3-acrylamidopropyl trimethylammonium chloride]); poly[3-methacrylamidopropyl trimethylammonium chloride](poly[3-methacrylamidopropyl trimethylammonium chloride] ); Poly[oxyethylene(dimethylimino)ethylene (dimethylimino)ethylene dichloride]); Acrylic acid/acrylamide/diallyldimethylammonium chloride Terpolymer of acrylic acid, acrylamide and diallyldimethylammonium Chloride; Terpolymer of acrylic acid, methacrylamidopropyl trimethylammonium chloride, and methyl acrylate; and Vinylcaprolactam/Vinyl P. Terpolymer of vinylcaprolactam, vinylpyrrolidone, and quaternized vinylimidazole; Poly(2-methacryloxyethyl)phosphorylchlorine-co-en-butyl methacrylate phosphorylcholine-co-n-butyl methacrylate)); consisting of poly[(dimethylamino) ethyl acrylate benzyl chloride quaternary salt] (PDMAEA BCQ) and poly[(dimethylamino) ethyl acrylate methyl chloride quaternary salt] (PDMAEA MCQ) It may include at least one selected from the group.

According to one aspect, the organic acids include pimelic acid, malic acid, malonic acid, maleic acid, acetic acid, adipic acid, oxalic acid, succinic acid, tartaric acid, citric acid, lactic acid, glutaric acid, glycolic acid, formic acid, fumaric acid, propionic acid, Butyric acid, hydroxybutyric acid, aspartic acid, itaconic acid, tricarbal acid, suberic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, picolinic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fuzaric acid, It may contain at least one selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and pyridinecarboxylic acid.

According to one aspect, the cationic compound and the organic acid may each be included in an amount of 0.001% to 5% by weight in the positive polishing slurry composition. If the cationic polymer and the organic acid are each less than 0.001% by weight in the positive polishing slurry composition, it is difficult to achieve the desired polishing selectivity and there are problems with dishing and defects, and if it is more than 5% by weight, agglomeration occurs. Therefore, there is a problem that polishing performance may decrease, scratches, and defects may occur.

According to one aspect, the positive polishing slurry composition may further include a pH adjuster.

According to one aspect, the pH adjuster includes nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, hydrobromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, and propionic acid. , fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, and an acidic substance containing at least one selected from the group consisting of salts thereof. ; and selected from the group consisting of ammonia, 2-amino-2-methyl-1-propanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate and imidazole. It may contain at least one selected from the group consisting of an alkaline substance containing at least one of the following.

According to one aspect, the pH of the positive polishing slurry composition may be 2 to 7. If the pH is outside the above range, there is a problem in that dispersion stability rapidly decreases and aggregation occurs.

The additive solution according to an embodiment of the present invention can exhibit excellent polishing selectivity, high flatness, and low dishing while maintaining dispersion stability and high polishing rate when applied to a positive polishing composition exhibiting a positive charge.

According to one aspect, the abrasive particles may be ceria dispersed with positive charges. The ceria dispersed with positive charges is mixed with an additive solution activated with positive charges, so that higher step removal performance and an automatic polishing stop function can be implemented.

According to one aspect, the abrasive particles include at least one selected from the group consisting of metal oxides, metal oxides coated with organic or inorganic materials, and the metal oxides in a colloidal state, and the metal oxides include silica, It may include at least one selected from the group consisting of ceria, zirconia, alumina, titania, barium titania, germania, mangania, and magnesia. For example, the abrasive particles may be colloidal ceria.

The abrasive particles may include those manufactured by a liquid method. The liquid method is a sol-gel method in which a chemical reaction occurs with an abrasive particle precursor in an aqueous solution and grows crystals to obtain fine particles, or a coprecipitation method in which abrasive particle ions are precipitated in an aqueous solution, and abrasive particles are formed under high temperature and high pressure. It can be manufactured by applying hydrothermal synthesis methods, etc. Abrasive particles manufactured by a liquid method are dispersed so that the surface of the abrasive particles has a positive charge.

The abrasive particles may be single crystalline. When using single crystalline abrasive particles, a scratch reduction effect can be achieved compared to polycrystalline abrasive particles, dishing can be improved, and cleanability after polishing can be improved.

The shape of the abrasive particles may include at least one selected from the group consisting of spherical, angular, needle-shaped, and plate-shaped, and may preferably be spherical.

According to one aspect, the abrasive particles may include primary particles of 5 nm to 150 nm and secondary particles of 30 nm to 300 nm. The measurement of the average particle diameter of the abrasive particles is the average value of the particle diameters of a plurality of particles within a viewing range that can be measured by scanning electron microscopy analysis or dynamic light scattering. The size of the primary particles should be 150 nm or less to ensure particle uniformity, and if it is less than 5 nm, the polishing rate may decrease. Regarding the size of the secondary particles in the polishing slurry composition for the STI process, If the secondary particle size is less than 30 nm, excessive small particles are generated due to milling, which reduces cleanability and causes excessive defects on the wafer surface. If it exceeds 300 nm, excessive polishing occurs and selectivity adjustment is difficult. It becomes difficult, and dishing, erosion and surface defects are likely to occur.

According to one aspect, in addition to single-sized particles, the abrasive particles may be mixed particles containing a multi-dispersion type particle distribution. For example, abrasive particles having two different average particle sizes are mixed. It may have a bimodal particle distribution, or it may have a particle size distribution showing three peaks by mixing abrasive particles with three different average particle sizes. Alternatively, four or more types of abrasive particles having different average particle sizes may be mixed to have a polydisperse particle distribution. By mixing relatively large and relatively small abrasive particles, better dispersibility can be achieved and the effect of reducing scratches on the wafer surface can be expected.

According to one aspect, the positive polishing slurry composition may be a positive slurry composition that exhibits a positive charge, and the zeta potential of the slurry composition may be in the range of +5 mV to +70 mV. Due to the positively charged abrasive particles, high dispersion stability is maintained and agglomeration of the abrasive particles does not occur, thereby reducing the occurrence of micro-scratches.

According to one aspect, the positive polishing slurry composition may include a concentration process and a dilution process in the manufacturing process. According to one side, the positive polishing slurry composition further includes water, and the ratio of the polishing liquid:water:additive liquid may be 1:3 to 10:1 to 8. The water may include, for example, deionized water, ion-exchanged water, and ultrapure water.

According to one aspect, it may be provided in a two-component form in which the polishing liquid and the additive liquid are prepared separately and mixed immediately before polishing, or it may be provided in a one-component form in which the polishing liquid and the additive liquid are mixed.

According to one aspect, an oxide film and a nitride film on a blanket wafer using the positive polishing slurry composition; Alternatively, when polishing a wafer including an oxide film and a polysilicon film, the polishing selection ratio of the oxide film: nitride film or the oxide film: polysilicon film may be 10:1 to 100:1.

According to one aspect, an oxide film and a nitride film on a blanket wafer using the positive polishing slurry composition; Or, when polishing a wafer including an oxide film and a polysilicon film, the polishing rate of the oxide film may be 1,000 Å/min to 4,000 Å/min, and the polishing rate of the nitride film or the polysilicon film may be 50 Å/min or less. there is. In particular, loss to the nitride layer can be reduced even during over-polishing in a cell type pattern.

Hereinafter, the present invention will be described in more detail through examples and comparative examples.

However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited to the following examples.

<Preparation of additive>

Example

Histidine as a cationic compound, lactic acid as an organic acid, and an additive compound were mixed in ultrapure water under the conditions shown in Table 1 below, and an additive solution of pH 4.5 was prepared using nitric acid.

Histidine
content Lactic acid
content Addition Compound Added compound content Example 1 1.5x 1x Proline 1.0x Example 2 1.5x 1x Proline 1.5x Example 3 1.5x 1x Proline 2.0x Example 4 1.5x 1x Proline 2.5x Example 5 1.5x 1x Proline 3.0x Example 6 1.5x 1x Picolinic acid 1.5x Example 7 1.0x 1x Picolinic acid 2.5x Example 8 1.25x 1x Picolinic acid 2.0x Example 9 1.5x 1x Glucose (Dextrose) 3.5x Example 10 1.5x 1x D-Glucosamine hydrochloride 0.5x Example 11 1.5x 1x D-Glucosamine hydrochloride 1.5x Example 12 1.5x 1x D-(+)-Glucose monohydrate 1.5x Example 13 1.5x 1x N-Acetyl-D-glucosamine 1.5x Example 14 1.5x 1x N-Acetyl-D-glucosamine 3.5x Example 15 1.5x 1x D-()-Ribose 1.5x

Comparative example

Histidine as a cationic compound, lactic acid as an organic acid, and an additive compound were mixed in ultrapure water under the conditions shown in Table 1 below, and an additive solution of pH 4.5 was prepared using nitric acid.

Histidine
content Lactic acid
content Addition Compound Added compound content Comparative Example 1 1x 1x - Comparative Example 2 1.5x 1x - Comparative Example 3 2x 1x - Comparative Example 4 1.5x 1x Piperazine 1.5x Comparative Example 5 1.5x 1x 1-Methylpiperazine 1.5x Comparative Example 6 1.5x 1x Morpholine 1.5x Comparative Example 7 1.5x 1x 4-Aminobutyric acid 1.0x Comparative Example 8 1.5x 1x Glycine 1.5x Comparative Example 9 1.5x 1x L-Serine 1.5x Comparative Example 10 1.5x 1x Glutamic acid 1.5x Comparative Example 11 1.5x 1x Threonine 1.5x Comparative Example 12 1.5x 1x L(+)-Aspartic acid 1.5x

<Preparation of positive polishing slurry composition>

A positive polishing slurry composition was prepared by mixing each of the additive solutions of Examples 1 to 15 and Comparative Examples 1 to 12 with a slurry composition containing 5% by weight of colloidal ceria abrasive particles.

A non-pattern wafer (NPW) and a pattern wafer were each polished using the polishing slurry compositions of Examples 1 to 15 and Comparative Examples 1 to 12 under the following polishing conditions.

[Polishing conditions]

1. Polisher: AP-300 (CTS Company)

2. Pad: K7 (Rohm&Hass)

3. Polishing time: 60 s

4. Table RPM: 63

5. Spindle RPM: 57

6. Flow rate: 300 ml/min

7. Wafers used: PE-TEOS non-patterned wafer, Cell Type Nitride patterned wafer

8. Pressure: 4.0 psi

Figure 1 is a view showing the cross-sectional structure of the wafer after pattern evaluation of the wafer using the positive polishing slurry composition according to Examples 1 to 15 and Comparative Examples 1 to 12 of the present invention. Based on the information on the pattern wafer in FIG. 1, the pattern wafer overpolishing time was set in the first polishing compared to the first non-pattern wafer (NPW). After setting the removal time to 2,000 Å, over-polishing was performed to check the degree of dishing.

Table 3 below shows the polishing rate and space size of the non-patterned wafer after polishing the non-patterned wafer and the patterned wafer using the positive polishing slurry composition containing the additive solution of Examples 1 to 15 and Comparative Examples 1 to 12 of the present invention. This shows the dishing results of a wafer with a pattern of 2 mm.

Addition Compound Unpatterned wafer
Polishing rate
(Å/min) pattern dishing
(Å) 2mm Example 1 Proline 2345 1150 Example 2 Proline 2245 412 Example 3 Proline 2145 456 Example 4 Proline 1975 518 Example 5 Proline 1834 584 Example 6 Picolinic acid 1396 571 Example 7 Picolinic acid 1994 909 Example 8 Picolinic acid 1866 748 Example 9 Glucose (Dextrose) 1762 517 Example 10 D-Glucosamine hydrochloride 2203 493 Example 11 D-Glucosamine hydrochloride 751 - Example 12 D-(+)-Glucose monohydrate 2446 794 Example 13 N-Acetyl-D-glucosamine 3842 - Example 14 N-Acetyl-D-glucosamine 2108 501 Example 15 D-()-Ribose 2138 912 Comparative Example 1 - 2878 2014 Comparative Example 2 - 2345 1843 Comparative Example 3 - 1654 1754 Comparative Example 4 Piperazine 2157 1864 Comparative Example 5 1-Methylpiperazine 2387 1913 Comparative Example 6 Morpholine 2452 1798 Comparative Example 7 4-Aminobutyric acid 2390 1387 Comparative Example 8 Glycine 2381 1680 Comparative Example 9 L-Serine 2808 1754 Comparative Example 10 Glutamic acid 2727 1326 Comparative Example 11 Threonine 2348 1654 Comparative Example 12 L(+)-Aspartic acid 2485 1578

Referring to Table 3, Comparative Examples 1 to 3 do not contain an added compound, Comparative Examples 4 to 6 include an added compound having only an aromatic ring, and Comparative Examples 6 include an added compound having only a hydroxy group, a carboxyl group, or both. Compared to the amount of dishing generated in Comparative Examples 7 to 12, it can be seen that the amount of dishing generated in Examples 1 to 15 containing an added compound having an aromatic ring and a hydroxy group, a carboxyl group, or both is significantly low.

That is, the positive polishing slurry composition according to the present invention contains the above-mentioned additive compound containing an aromatic ring and a hydroxy group, a carboxyl group, or both, and thus can be used in the big pattern area (space size of 0.1 mm or more) of the cell type pattern. Low dishing can be achieved.

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description. For example, even if the described techniques are performed in a different order than the described method, and/or the described components are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents. Adequate results can be achieved. Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims (15)

An additive solution containing a cationic compound, an organic acid, and an additive compound; and
It includes a polishing liquid containing abrasive particles,
After polishing a wafer containing an oxide film and a nitride film or an oxide film and a polysilicon film, the amount of dishing of the wafer having a pattern with a space size of 0.1 mm to 5 mm is 1000 Å or less,
The added compound is proline,
The added compound is contained in 0.01% by weight to 0.5% by weight in the slurry composition,
Positive polishing slurry composition. delete delete delete delete According to paragraph 1,
The cationic compound includes at least one selected from the group consisting of amino acids, polymer polysaccharides to which glucosamine compounds are bound, and amine group-containing polymers.
Positive polishing slurry composition. According to paragraph 1,
The organic acids include pimelic acid, malic acid, malonic acid, maleic acid, acetic acid, adipic acid, oxalic acid, succinic acid, tartaric acid, citric acid, lactic acid, glutaric acid, glycolic acid, formic acid, fumaric acid, propionic acid, butyric acid, and hydroxybutyric acid. , aspartic acid, itaconic acid, tricarbal acid, suberic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, picolinic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fuzaric acid, phthalic acid, isophthalic acid, Containing at least one selected from the group consisting of terephthalic acid and pyridine carboxylic acid,
Positive polishing slurry composition. According to paragraph 1,
The cationic compound and the organic acid are each included in an amount of 0.001% to 5% by weight in the positive polishing slurry composition.
Positive polishing slurry composition. According to paragraph 1,
The positive polishing slurry composition further includes a pH adjuster,
Positive polishing slurry composition. According to clause 9,
The pH adjuster is,
Nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, hydrobromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid. , an acidic substance containing at least one selected from the group consisting of benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid and salts thereof; and selected from the group consisting of ammonia, 2-amino-2-methyl-1-propanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate and imidazole. an alkaline substance containing at least one of the following; containing at least one selected from the group consisting of,
Positive polishing slurry composition. According to paragraph 1,
The pH of the positive polishing slurry composition is 2 to 7,
Positive polishing slurry composition. According to paragraph 1,
The abrasive particles are,
It is ceria dispersed with positive charge,
Positive polishing slurry composition. According to paragraph 1,
The abrasive particles include primary particles of 5 nm to 150 nm and secondary particles of 30 nm to 300 nm,
Positive polishing slurry composition. According to paragraph 1,
The surface zeta potential of the positive polishing slurry composition is +5 mV to +70 mV,
Positive polishing slurry composition. According to paragraph 1,
An oxide film and a nitride film on a blanket wafer using the positive polishing slurry composition; Or when polishing a wafer containing an oxide film and a polysilicon film,
The polishing rate of the oxide film is 1,000 Å/min to 4,000 Å/min,
The polishing rate of the nitride film or the polysilicon film is 50 Å/min or less,
Positive polishing slurry composition.