KR20180065558A - High selectivity slurry composition of oxide film to tungsten film - Google Patents

Abstract

The present invention relates to a slurry composition having high selectivity of an oxide film to a tungsten film. The slurry composition having high selectivity of an oxide film to a tungsten film according to an embodiment of the present invention contains polishing particles, an oxide film polishing enhancer including water-soluble polysaccharide, and a dispersing agent. An objective of the present invention is to provide a slurry composition having high selectivity of an oxide film to a tungsten film which can improve the polishing rate of the oxide film and improve the polishing selectivity of the oxide film and the tungsten film.

Description

TECHNICAL FIELD [0001] The present invention relates to a high selectivity slurry composition for an oxide film for a tungsten film,

The present invention relates to high selectivity slurry compositions of oxide films for tungsten films.

The chemical mechanical polishing (CMP) process refers to a process of polishing the surface of a semiconductor wafer in a flat manner using a slurry containing an abrasive and various compounds while rotating in contact with the polishing pad. Generally, it is known that a metal polishing process is repeatedly performed in a process in which a metal oxide (MO _x ) is formed by an oxidizing agent and a process in which abrasive grains are removed from a formed metal oxide.

The polishing process of the tungsten layer, which is widely used as the wiring of the semiconductor device, is carried out by a mechanism in which tungsten oxide (WO ₃ ) is formed by an oxidizing agent and a potential adjusting agent, and a process in which tungsten oxide is removed by abrasive particles is repeated. In addition, an insulating film may be formed under the tungsten layer, or a pattern such as a trench may be formed. In this case, a high polishing selectivity of the tungsten layer and the insulating film is required in the CMP process. In order to improve the polishing selectivity of tungsten to the insulating film, various components are added to the slurry or the content of the oxidizing agent and the catalyst contained in the slurry is controlled. Despite these efforts, a slurry for tungsten polishing, which still realizes high polishing selectivity, has not been developed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high selectivity non-slurry composition for an oxide film on a tungsten film which can improve a polishing rate of an oxide film and a tungsten film, .

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

According to one embodiment, abrasive particles; An oxide film polishing improver including a water-soluble polysaccharide; And a dispersant, wherein the high selectivity non-slurry composition of the oxide film for the tungsten film is provided.

According to one aspect, the water soluble polysaccharide is selected from the group consisting of Gellangum, Rhamsan gum, Welangum, Xanthangum, Guargum, Karayagum, Locust bean gum, Tragacanth gum, Gum Ghatti, Tara gum, konjac gum, Algin, Agar, and the like. , Carrageenan, Furcellaran, Curdlan, Cyclodextrin, Alginic acid, Casein, Tatagum, Tamarind gum, At least one selected from the group consisting of Pectin, Glucomannan, Cyclodextrin syrup, Arabino Galactan, Pulluian and Acacia gum, May include.

According to one aspect, the oxide film polishing enhancer may be 0.01 wt% to 1 wt% of the high-selectivity slurry composition of the oxide film for the tungsten film.

According to one aspect, the dispersant may include at least one selected from the group consisting of a polycarboxylic acid compound, a polysulfonic acid compound, a carboxylic acid-sulfonic acid copolymer, an alkylsulfonic acid formalin condensate and a salt of an organic base compound thereof .

According to one aspect, the polycarboxylic acid compound includes at least one selected from the group consisting of polyacrylic acid, polymethacrylic acid, polymaleic acid, acrylic acid-styrene copolymer and acrylic acid-maleic acid copolymer, The compound includes at least any one selected from the group consisting of polyvinylsulfonic acid, polystyrenesulfonic acid, polyacrylamidomethylpropanesulfonic acid, poly-alpha-methylstyrenesulfonic acid and poly-p-methylstyrenesulfonic acid, and the carboxylic acid- The copolymer may include a polyacrylic acid-sulfonic acid copolymer or a polysulfonic acid-acrylamide copolymer, and the alkylsulfonic acid formalin condensate may include a naphthalenesulfonic acid formalin condensate.

According to one aspect, the dispersant may be 0.1 wt% to 1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film.

According to one aspect, the method further comprises at least one pH adjusting agent selected from the group consisting of organic acids, organic acid salts, inorganic acids, and inorganic acid salts, wherein the organic acid is selected from the group consisting of malic acid, maleic acid, malonic acid, oxalic acid, formic acid, At least one selected from the group consisting of picolinic acid, citric acid, succinic acid, tartaric acid, glutaric acid, glutamic acid, glycolic acid, propionic acid, fumaric acid, salicylic acid, pimelic acid, benzoic acid, butyric acid, oxalic acid, aspartic acid and phthalic acid Wherein said organic acid salt comprises a salt of said organic acid and wherein said inorganic acid is selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, bromic acid, iodic acid, sulfamic acid, perchloric acid, chromic acid, At least one selected from the group consisting of hydrofluoric acid and fluoroboric acid, wherein the inorganic acid salt is a salt of the inorganic acid May include.

According to one aspect, the abrasive particles comprise at least one selected from the group consisting of a metal oxide coated with a metal oxide, an organic or inorganic material, and a metal oxide in a colloidal state, and the metal oxide is selected from the group consisting of silica, , Zirconia, alumina, titania, barium titania, germania, manganese, and magnesia.

According to one aspect, the size of the abrasive particles may be a single size particle having a particle size of 10 nm to 200 nm or a mixed particle of two or more kinds.

According to one aspect, the abrasive particles may be 1 wt% to 5 wt% of the high selectivity slurry composition of the oxide film for the tungsten film.

According to one aspect, the pH of the high selectivity slurry composition of the oxide film for the tungsten film may be in the range of 1 to 5.

According to one aspect, the polishing rate for the oxide film is 500 ANGSTROM to 1,200 ANGSTROM / min, the polishing rate for the tungsten film is 30 ANGSTROM to 100 ANGSTROM / min, and the polishing rate of the oxide film to the polishing rate of the tungsten film May be 10 or more.

The high selectivity non-slurry composition of the oxide film for the tungsten film according to an embodiment can enhance the surface hydration of the oxide film due to the hydroxyl group by the oxide film polishing improver, thereby greatly improving the oxide film polishing rate. As a result, the polishing selectivity between tungsten and the oxide film can be improved. By using a high selectivity non-slurry composition of the oxide film for the tungsten film, erosion can be reduced, dishing can be suppressed, surface roughness can be improved, and the occurrence of by-products can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, terms used in this specification are terms used to appropriately express the preferred embodiments of the present invention, which may vary depending on the user, the intention of the operator, or the practice of the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a high selectivity non-slurry composition of an oxide film for a tungsten film of the present invention will be described in detail with reference to examples and drawings. However, the present invention is not limited to these embodiments and drawings.

According to one embodiment, abrasive particles; An oxide film polishing improver including a water-soluble polysaccharide; And a dispersant, wherein the high selectivity non-slurry composition of the oxide film for the tungsten film is provided.

The high selectivity non-slurry composition of the oxide film for the tungsten film according to one embodiment can enhance the surface hydration of the oxide film by the oxide film polishing improver to greatly improve the oxide film polishing rate. As a result, the polishing selectivity between tungsten and the oxide film can be improved. By using a high selectivity non-slurry composition of the oxide film for the tungsten film, erosion can be reduced, dishing can be suppressed, surface roughness can be improved, and the occurrence of by-products can be reduced.

According to one aspect, the abrasive particles comprise at least one selected from the group consisting of a metal oxide coated with a metal oxide, an organic or inorganic material, and a metal oxide in a colloidal state, and the metal oxide is selected from the group consisting of silica, , Zirconia, alumina, titania, barium titania, germania, manganese, and magnesia.

According to one aspect, the abrasive grains may include those produced by the liquid phase method. The liquid phase method includes a sol-gel method in which an abrasive particle precursor is caused to undergo a chemical reaction in an aqueous solution and crystals are grown to obtain fine particles, a coprecipitation method in which abrasive particle ions are precipitated in an aqueous solution, Hydrothermal synthesis method or the like.

According to one aspect, the size of the abrasive particles can be measured by SEM analysis or dynamic light scattering, Size particles of 10 nm to 200 nm or a mixture of two or more kinds of particles. Preferably, 10 nm to 50 nm. If the size of the abrasive grains is less than 10 nm, the polishing rate may be lowered. If the size of the abrasive grains is more than 200 nm, excessive polishing may occur and dishing, erosion and surface defects may occur.

According to one aspect of the present invention, the abrasive grains may have a particle size distribution in which two kinds of particles are mixed to form a bimodal form, or a particle size distribution in which three kinds of particles are mixed to show three peaks . The relatively large abrasive grains and the relatively small abrasive grains can be mixed to have better dispersibility and the effect of reducing the scratch on the wafer surface can be expected.

According to one aspect, the abrasive particles may be 1 wt% to 5 wt% of the high selectivity slurry composition of the oxide film for the tungsten film. When the abrasive grains are less than 1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film, there is a problem that the polishing rate is reduced. When the abrasive grains are more than 5 wt%, the polishing rate is too high, Surface defects can be generated by the residual particle adsorbability on the surface.

According to one aspect of the present invention, the water-soluble polysaccharide has a structure in which many hydroxyl groups increase the surface hydrophilic action of an oxide film (for example, TEOS) to increase dispersion stability in an aqueous solution state and increase the lubricity of the slurry composition in a CMP process, The polishing rate of the oxide film can be increased uniformly according to the position. The water-soluble polysaccharide may be selected from the group consisting of Gellangum, Rhamsan gum, Welangum, Xanthangum, Guargum, Karayagum, Arabicgum, Locust bean gum, Tragacanth gum, Gum Ghatti, Tara gum, konjac gum, Algin, Agar, Carrageenan, , Furcellaran, Curdlan, Cyclodextrin, Alginic acid, Casein, Tatagum, Tamarind gum, Pectin, And may include at least one selected from the group consisting of Glucomannan, Cyclodextrin syrup, Arabino Galactan, Pulluian and Acacia gum .

According to one aspect, the oxide film polishing enhancer may be 0.01 wt% to 1 wt% of the high-selectivity slurry composition of the oxide film for the tungsten film. When the oxide film polishing enhancer is less than 0.01 wt% of the high selectivity slurry composition of the oxide film for the tungsten film, the polishing rate and the etching rate of the oxide film are lowered, and the selectivity to the tungsten film and the oxide film is lowered. The coagulation of the abrasive particles and the polishing performance may be deteriorated.

According to one aspect, the dispersant may include at least one selected from the group consisting of a polycarboxylic acid compound, a polysulfonic acid compound, a carboxylic acid-sulfonic acid copolymer, an alkylsulfonic acid formalin condensate and a salt of an organic base compound thereof .

According to one aspect, the polycarboxylic acid compound includes at least one selected from the group consisting of polyacrylic acid, polymethacrylic acid, polymaleic acid, acrylic acid-styrene copolymer and acrylic acid-maleic acid copolymer, The compound includes at least any one selected from the group consisting of polyvinylsulfonic acid, polystyrenesulfonic acid, polyacrylamidomethylpropanesulfonic acid, poly-alpha-methylstyrenesulfonic acid and poly-p-methylstyrenesulfonic acid, and the carboxylic acid- The copolymer may include a polyacrylic acid-sulfonic acid copolymer or a polysulfonic acid-acrylamide copolymer, and the alkylsulfonic acid formalin condensate may include a naphthalenesulfonic acid formalin condensate.

According to one aspect, the dispersant may be 0.1 wt% to 1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film. When the dispersant is less than 0.1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film, the dispersing power is low and the precipitation proceeds quickly, so that abrasive particle dispersion can not be realized. When the dispersant is more than 1 wt% The dispersion stability is decreased, so that agglomeration occurs, which may cause scratches and defects.

According to one aspect, the pH of the high selectivity slurry composition of the oxide film for the tungsten film may be in the range of 1 to 5. Preferably, the pH of the high selectivity slurry composition of the oxide film for the tungsten film is 1.5 to 3. When the pH of the highly selective slurry composition for the oxide film for the tungsten film is out of the range of 1 to 5, the polishing rate of the metal film is lowered, the roughness of the surface is not constant, and corrosion, erosion, erosion, And defects such as surface imbalance. The pH can be adjusted by adding the following pH adjusting agent.

According to one aspect, it may further comprise at least one pH adjusting agent selected from the group consisting of organic acids, organic acid salts, inorganic acids and inorganic acid salts to prevent corrosion of tungsten or a polishing machine and to realize a pH range in which tungsten oxidation easily occurs have. The organic acid may be selected from the group consisting of malic acid, maleic acid, malonic acid, oxalic acid, formic acid, lactic acid, acetic acid, picolinic acid, citric acid, succinic acid, tartaric acid, glutaric acid, glutamic acid, glycolic acid, propionic acid, fumaric acid, At least one selected from the group consisting of butyric acid, oxalic acid, aspartic acid and phthalic acid, wherein the organic acid salt includes a salt of the organic acid, and the inorganic acid is at least one selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, At least one selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, iodic acid, sulfamic acid, perchloric acid, chromic acid, sulfurous acid, nitrous acid, boronic acid, hydrofluoric acid and fluoroboric acid, have.

According to one aspect, the polishing rate for the oxide film is 500 ANGSTROM to 1,200 ANGSTROM / min, the polishing rate for the tungsten film is 30 ANGSTROM to 100 ANGSTROM / min, and the polishing rate of the oxide film to the polishing rate of the tungsten film May be 10 or more. The hydroxyl group enhances the surface hydration of the oxide film by the oxide film polishing improver, thereby greatly improving the oxide film polishing rate.

The use of the high selectivity non-slurry composition of the oxide film for the tungsten film of the present invention can achieve a high polishing selectivity of the oxide film for the tungsten film and improve the surface roughness of the tungsten film.

Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples. However, the technical idea of the present invention is not limited or limited thereto.

Example

[ Example  One]

2.2% by weight of colloidal silica abrasive grains having a particle size of 65 nm, 0.02% by weight of guar gum as an oxide film polishing improver, and 0.3% by weight of polyvinylsulfonic acid as a dispersing agent, A high selectivity slurry composition of the oxide film for the tungsten film of 2.3 was prepared.

[ Example  2]

A high selectivity non-slurry composition of the oxide film for the tungsten film was prepared in the same manner as in Example 1, except that 0.06% by weight of guar gum was added in Example 1.

[ Example  3]

A high-selectivity non-slurry composition of an oxide film for a tungsten film was prepared in the same manner as in Example 1, except that 0.015 wt% of gellan gum was added as an oxide film polishing improver in Example 1.

[ Example  4]

A high selectivity slurry composition of the oxide film for the tungsten film was prepared in the same manner as in Example 3, except that 0.055% by weight of Gellan gum was added in Example 3.

[ Example  5]

A high-selectivity non-slurry composition of an oxide film for a tungsten film was prepared in the same manner as in Example 1, except that 0.01 wt% of xanthan gum was added as an oxide film polishing improver in Example 1.

[ Example  6]

A high-selectivity non-slurry composition of the oxide film for the tungsten film was prepared in the same manner as in Example 5, except that 0.05 wt% of xanthan gum was added in Example 1.

[ Example  7]

A high selectivity non-slurry composition of the oxide film for the tungsten film was prepared in the same manner as in Example 5 except that 0.1 wt% of xanthan gum was added in Example 1.

[ Comparative Example ]

A polishing slurry composition was prepared in the same manner as in Example 1, except that the oxide film polishing improver was not added in Example 1.

The wafers having the tungsten and oxide films formed thereon were polished under the following polishing conditions by using the high-selectivity non-slurry composition of the oxide film for the tungsten films of Examples 1 to 7 of the present invention and the polishing slurry composition of the comparative example.

<Polishing Condition>

1. Polishing equipment - ST01 (300mm)

2. Platen speed - 100 rpm

3. Carrier speed - 103 rpm

4. Wafer pressure - 3.0 psi

5. Slurry flow rate - 200 ml / min

6. Pad - KPX pad

Table 1 below shows the silica, the type and content of the oxide polishing abrasive improving agent, the pH of the slurry composition, the oxide film polishing rate, the tungsten polishing rate and the polishing rate of the slurry composition in the high-selectivity slurry composition of the oxide film for the tungsten film of the comparative example of the present invention and Examples 1 to 7 Oxide / tungsten polishing selectivity ratio.

division Silica
(weight%) Oxide film
Abrasive improver
(weight%) pH Oxide film
Polishing rate
(Å / min) tungsten
Polishing rate
(Å / min) Oxide film
/tungsten
Abrasive selection ratio Comparative Example 2.2 - 2.3 390 45 8.67 Example 1 2.2 Guar gum
0.02 2.3 512 41 12.49 Example 2 2.2 Guar gum
0.06 2.3 721 32 22.53 Example 3 2.2 Gellan gum
0.015 2.3 529 46 11.5 Example 4 2.2 Gellan gum
0.055 2.3 616 44 14.0 Example 5 2.2 Xanthan gum
0.01 2.3 661 34 19.44 Example 6 2.2 Xanthan gum
0.05 2.3 1,012 38 26.63 Example 7 2.2 Xanthan gum
0.1 2.3 1,174 39 30.10

The oxide / tungsten polishing selectivity of the slurry composition of the comparative example was 8.67 and the oxide / tungsten polishing selectivity of the oxide / tungsten polishing selectivity of the oxide / tungsten polishing composition of Examples 1 to 7 was more than 11.5. It can be seen that the oxide film polishing improver added to the high selectivity non-slurry composition for the oxide film for the tungsten film can improve the polishing rate by improving the polishing rate of the oxide film and increasing the difference in the polishing rate between the tungsten film and the oxide film.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the equivalents of the appended claims, as well as the appended claims.

Claims (12)

Abrasive particles;
An oxide film polishing improver including a water-soluble polysaccharide; And
Dispersing agent;
/ RTI &gt; wherein the oxide of the tungsten film is a tungsten film.
The method according to claim 1,
The water-soluble polysaccharide may be selected from the group consisting of Gellangum, Rhamsan gum, Welangum, Xanthangum, Guargum, Karayagum, Arabicgum, Locust bean gum, Tragacanth gum, Gum Ghatti, Tara gum, konjac gum, Algin, Agar, Carrageenan, , Furcellaran, Curdlan, Cyclodextrin, Alginic acid, Casein, Tatagum, Tamarind gum, Pectin, Wherein the composition comprises at least one selected from the group consisting of Glucomannan, Cyclodextrin syrup, Arabino Galactan, Pulluian and Acacia gum. High selectivity non-slurry composition of oxide film for tungsten film.
The method according to claim 1,
Wherein the oxide film polishing enhancer is 0.01 wt% to 1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film.
The method according to claim 1,
Wherein the dispersing agent comprises at least one selected from the group consisting of a polycarboxylic acid compound, a polysulfonic acid compound, a carboxylic acid-sulfonic acid copolymer, an alkylsulfonic acid formalin condensate and a salt of an organic base compound thereof, tungsten A high selectivity slurry composition of an oxide film on a film.
5. The method of claim 4,
Wherein the polycarboxylic acid compound includes at least any one selected from the group consisting of polyacrylic acid, polymethacrylic acid, polymaleic acid, acrylic acid-styrene copolymer and acrylic acid-maleic acid copolymer,
Wherein the polysulfonic acid compound includes at least any one selected from the group consisting of polyvinylsulfonic acid, polystyrenesulfonic acid, polyacrylamidomethylpropanesulfonic acid, poly- alpha -methylstyrenesulfonic acid and poly-p-methylstyrenesulfonic acid,
The carboxylic acid-sulfonic acid copolymer includes a polyacrylic acid-sulfonic acid copolymer or a polysulfonic acid-acrylamide copolymer,
Wherein the alkylsulfonic acid formalin condensate comprises a naphthalenesulfonic acid formalin condensate.
The method according to claim 1,
Wherein the dispersant is 0.1 wt% to 1 wt% of the high selectivity slurry composition of the oxide film for the tungsten film.
The method according to claim 1,
At least one pH adjusting agent selected from the group consisting of organic acids, organic acid salts, inorganic acids, and inorganic acid salts,
The organic acid may be selected from the group consisting of malic acid, maleic acid, malonic acid, oxalic acid, formic acid, lactic acid, acetic acid, picolinic acid, citric acid, succinic acid, tartaric acid, glutaric acid, glutamic acid, glycolic acid, propionic acid, fumaric acid, , At least one selected from the group consisting of butyric acid, oxalic acid, aspartic acid and phthalic acid,
The organic acid salt includes a salt of the organic acid,
The inorganic acid is at least one selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, bromic acid, iodic acid, sulfamic acid, perchloric acid, chromic acid, sulfurous acid, nitrous acid, Including,
Wherein said inorganic acid salt comprises a salt of said inorganic acid.
High selectivity non-slurry composition of oxide film for tungsten film.
The method according to claim 1,
The above-
At least one selected from the group consisting of a metal oxide coated with a metal oxide, an organic or inorganic material, and a metal oxide in a colloidal state,
Wherein the metal oxide comprises at least one selected from the group consisting of silica, ceria, zirconia, alumina, titania, barium titania, germania, manganese, and magnesia.
The method according to claim 1,
Wherein the abrasive grains have a size of 10 nm to 200 nm, or a mixture of two or more grains.
The method according to claim 1,
Wherein the abrasive grains are from 1 wt% to 5 wt% of the high selectivity slurry composition of the oxide film for the tungsten film.
The method according to claim 1,
Wherein the pH of the high selectivity non-slurry composition of the oxide film for the tungsten film is in the range of 1 to 5.
The method according to claim 1,
The polishing rate for the oxide film is 500 ANGSTROM to 1,200 ANGSTROM / min, the polishing rate for the tungsten film is 30 ANGSTROM to 100 ANGSTROM / min, and the ratio of the polishing rate of the oxide film to the polishing rate of the tungsten film is 10 By weight based on the total weight of the tungsten film.