KR102685883B1 - Chemical mechanical polishing slurry composition for ild polishing process or sti polishing process and polishing method using the same - Google Patents

Abstract

A chemical mechanical polishing slurry composition for an ILD polishing process or an STI polishing process and a polishing method using the same are disclosed.
The chemical mechanical polishing slurry composition has different polishing characteristics depending on the content of deionized water. When the content of deionized water is low, the ILD (Interlayer Dielectric) polishing process can be applied through high step removal power and implementation of an auto stop function. This is possible, and when the deionized water content is high, the STI (Shallow Trench Isolation) polishing process can be applied through high oxide film removal power, high oxide film to nitride film selection ratio, and trench field oxide film passivation effect.

Description

Chemical mechanical polishing slurry composition for ILD polishing process or STI polishing process and polishing method using the same {CHEMICAL MECHANICAL POLISHING SLURRY COMPOSITION FOR ILD POLISHING PROCESS OR STI POLISHING PROCESS AND POLISHING METHOD USING THE SAME}

The present invention relates to a chemical mechanical polishing slurry composition for an ILD polishing process or an STI polishing process and a polishing method using the same.

Recently, with the high integration and high performance of semiconductor devices, the line width of the wiring pattern is becoming finer and the structure is becoming increasingly multi-layered. In order to improve the precision of photolithography, interlayer flatness in each process is a very important factor. The CMP process is currently in the spotlight as such a planarization technology, and the CMP process can be classified into oxide CMP process, metal CMP process, and poly-Si CMP process depending on the material to be polished. .

Representative semiconductor processes in which the CMP process that polishes the oxide film is applied include the ILD (Interlayer Dielectric) polishing process and the STI (Shallow Trench Isolation) polishing process. The ILD polishing process is a process to remove excessively deposited silicon oxide film (SiO ₂ ) for interlayer insulation, and the STI polishing process is a process to separate devices by forming a trench for insulation between chips. am.

When performing the CMP process in an existing semiconductor process, the slurry and additives used for each polishing process were different. That is, in the case of the STI polishing process, a nitride film (Si ₃ N ₄ ) is generally used as a polishing stop film, and the polishing stop film prevents loss of the oxide film in the trench area. On the other hand, in the case of the ILD polishing process, there is generally no separate polishing stop film, and polishing is automatically stopped when the step height of the oxide film (SiO ₂ ) to be polished is removed and flattening progresses. Therefore, when a slurry for the ILD polishing process is used in the STI polishing process, there is a high possibility that the oxide film to be polished is not effectively removed, and the low selectivity of the oxide film to the nitride film causes erosion of the nitride film, which is the polishing stop film, during the polishing process. This may result in damage to the device. Conversely, when STI slurry is used in the ILD process, the automatic stop function is not implemented, so there is a high possibility of over-polishing beyond the target polishing stop position, which may result in loss of the device. Therefore, there is a problem in that different types of slurries must be used for each process.

Accordingly, while researching to solve the above-mentioned inconvenience, the present inventors discovered that by adjusting the content of deionized water in the new polishing slurry composition, the polishing slurry composition can be applied to the ILD polishing process or the STI polishing process, respectively. discovered and completed the present invention. In this regard, Republic of Korea Patent No. 10-0600599 discloses a CMP slurry with enhanced storage stability.

The present invention was developed to solve the above-described problem, and an embodiment of the present invention provides a chemical mechanical polishing slurry composition for an ILD polishing process or an STI polishing process.

Another embodiment of the present invention provides a polishing method using the chemical mechanical polishing slurry composition.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

As a technical means for achieving the above-described technical problem, one aspect of the present invention is,

Abrasives; dispersant; pH adjuster; polishing additives; and deionized water; and provides a chemical mechanical polishing slurry composition that can be used in an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process depending on the content of the deionized water.

The abrasive may be a metal oxide.

The metal oxide is selected from the group consisting of silica (SiO ₂ ), zirconia (ZrO ₂ ), alumina (Al ₂ O ₃ ), ceria (CeO ₂ ), titania (TiO ₂ ), germania (GeO ₂ ), and combinations thereof. It may contain a selected substance.

The dispersant includes arginine, histidine, lysine, aspartic acid, glutamic acid, serine, threonine, asparagine, glutamine, glycine, proline, alanine, valine, isoleucine, leucine, phenylalanine, and betaine. and combinations thereof.

The polishing additive is a cationic polymer; cationic compounds; nonionic surfactants; And it may include a polishing accelerator.

The cationic polymer includes polyacrylamide-diallyl dimethyl ammonium chloride (P(AAm-co-DADMAC)), polyetherimide (PEI), poly diallyl dimethyl ammonium chloride (Poly(DADMAC)), and polyacrylamide (PAAM). ) and combinations thereof.

The cationic compound a) contains two or more nitrogen atoms in one molecule, b) each nitrogen atom is connected to a single bond of (C2~C3) alkylene and can rotate along the bond axis, and c) each nitrogen atom is connected to a single bond (C2~C3) alkylene. It may include a material selected from the group consisting of organic amine compounds having an average number of directly bonded carbon atoms per atom (C/N avg.) of 2 to 3, salts thereof, and mixtures thereof.

The nonionic surfactant may include a material selected from the group consisting of polyethylene glycol, polypropylene glycol, polyvinyl alcohol, glycerin, polyglycerin, polyvinylpyrrolidone, and combinations thereof.

The polishing accelerator may include a material selected from the group consisting of polysaccharide compounds, polyol compounds, and combinations thereof.

The abrasive; dispersant; pH adjuster; When the weight ratio of the content of the polishing additive and the deionized water is 1:1 to 3, the chemical mechanical polishing slurry may be used in an ILD (Interlayer Dielectric) polishing process.

The abrasive; dispersant; pH adjuster; When the weight ratio of the content of the polishing additive and the deionized water is 1:5 to 10, the chemical mechanical polishing slurry may be used in an STI (Shallow Trench Isolation) polishing process.

The ILD (Interlayer Dielectric) polishing process is to polish a pattern wafer having concave portions and convex portions, and when polishing the pattern wafer with the chemical mechanical polishing slurry composition, the ratio of the polishing speed of the concave portion and the convex portion is 1:30 to 1:30. It could be 40.

The selectivity ratio of the oxide film to the nitride film of the chemical mechanical polishing slurry composition used in the Shallow Trench Isolation (STI) polishing process may be 30 to 50.

The chemical mechanical polishing slurry composition may be characterized in that it can maintain the characteristics before slurry aging even after slurry aging for 2 weeks or more.

In addition, another aspect of the present invention is,

A polishing method is provided, characterized in that an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process is performed using the chemical mechanical polishing slurry composition.

The slurry composition of the present invention has different polishing characteristics depending on the content of deionized water, and accordingly, it is possible to perform two processes using one type of slurry. In other words, when the deionized water content is low, it can be applied to the ILD polishing process through high step removal power and the implementation of an automatic stop function, and when the deionized water content is high, it can be applied to the ILD polishing process, and when the deionized water content is high, it has high oxide film removal power and a high oxide film to nitride film selection ratio. ) It can be applied to the STI polishing process through the field oxide film passivation effect. In addition, because it has excellent dispersibility, it can be used as a one-liquid type and has improved storage properties.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a schematic diagram showing an ILD polishing process according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing an STI polishing process according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail. However, the present invention can be implemented in various different forms, and the present invention is not limited to the embodiments described herein, and the present invention is only defined by the claims to be described later.

In addition, the terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the entire specification of the present invention, 'including' a certain element means that other elements may be further included rather than excluding other elements, unless specifically stated to the contrary.

The first aspect of the present application is,

Abrasives; dispersant; pH adjuster; polishing additives; and deionized water, and provides a chemical mechanical polishing slurry composition that can be used in an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process depending on the content of the deionized water.

Hereinafter, the chemical mechanical polishing slurry composition according to the first aspect of the present application will be described in detail with reference to FIGS. 1 and 2.

In one embodiment of the present application, the ILD (Interlayer Dielectric) polishing process is a process for removing an excessively formed silicon oxide film (SiO ₂ ) for interlayer insulation, as shown in FIG. 1 . On the other hand, the STI (Shallow Trench Isolation) polishing process is a process of separating devices by forming a trench to insulate between chips. Therefore, as shown in FIG. 2, the silicon oxide film (SiO ₂ ) to be polished is must be effectively removed, and erosion of the silicon nitride film (Si ₃ N ₄ ) must be minimized.

In one embodiment of the present application, the metal oxide abrasive is silica (SiO ₂ ), zirconia (ZrO ₂ ), alumina (Al ₂ O ₃ ), ceria (CeO ₂ ), titania (TiO ₂ ), and germania (GeO ₂ ). and combinations thereof, and preferably includes ceria (CeO ₂ ). At this time, the metal oxide may preferably be wet synthesized.

In one embodiment of the present application, the size of the mixed abrasive may be a primary particle size of 10 to 80 nm and a secondary particle size of 80 to 200 nm. The size of the abrasive may have a different meaning depending on the shape of the abrasive. For example, if it is in the shape of a sphere, it may mean the diameter of the sphere, and if it is oval, it may be the diameter of the major axis or the diameter of the minor axis. If the size of the abrasive is less than the above range, the size may be too small and polishing may not be performed well when the object to be polished is later polished with a chemical mechanical polishing slurry composition containing the abrasive. If the size of the abrasive is greater than the above range, the size may not be performed well. If it is too large, scratches may occur on the object being polished during polishing.

In one embodiment of the present application, the content of the abrasive may be 0.1 to 5 parts by weight based on 100 parts by weight of the polishing slurry composition. If the content of the abrasive is less than 0.1 parts by weight compared to 100 parts by weight of the polishing slurry composition, a problem may occur in which the polishing speed of the polishing slurry composition is lowered, and if it is more than 5 parts by weight, problems may occur in terms of dispersion stability.

In one embodiment of the present application, the dispersant is added to increase the dispersion stability of the polishing slurry composition, and the dispersant may include an amino acid that is a zwitterionic compound, for example, arginine, histidine, lysine, Aspartic acid, glutamic acid, serine, threonine, asparagine, glutamine, glycine, proline, alanine, valine, isoleucine, leucine, phenylalanine, betaine and combinations thereof.

In one embodiment of the present application, the content of the dispersant may be 0.5 parts by weight to 10 parts by weight based on 100 parts by weight of the abrasive in the polishing slurry composition.

In one embodiment of the present application, the pH adjusting agent may be an acid or base substance. When the pH adjuster is an acid, it may include a substance selected from the group consisting of organic acids including sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, acetic acid, and combinations thereof, but is not limited thereto. In addition, when the pH adjuster is a basic substance, it may include a substance selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonia, ammonium hydroxide, ammonium carbonate, organic amine, amino alcohol, and combinations thereof, but is limited thereto. It doesn't work.

In one embodiment of the present application, the pH of the chemical mechanical polishing slurry composition may be 4 to 8. If the pH of the chemical mechanical polishing slurry composition is less than 4, the polishing rate for the silicon oxide film, which is a film to be polished, is lowered, resulting in lower polishing performance, and if it is more than 8, the polishing slurry composition may have a high polishing rate for the silicon nitride film, and therefore , the polishing selectivity of the silicon oxide film compared to the silicon nitride film may appear low.

In one embodiment of the present application, the polishing additive is a cationic polymer; cationic compounds; nonionic surfactants; And it may include a polishing accelerator.

In one embodiment of the present application, the cationic polymer may be added to achieve a high selectivity of the silicon oxide film to the silicon nitride film and an auto stop function. The cationic polymer is, for example, polyacrylamide-diallyl dimethyl ammonium chloride (P(AAm-co-DADMAC)), polyetherimide (PEI), poly diallyl dimethyl ammonium chloride (Poly(DADMAC)), poly It may contain a material selected from the group consisting of acrylamide (PAAM) and combinations thereof.

In one embodiment of the present application, the content of the cationic polymer may be 0.0001 part by weight to 0.1 part by weight based on 100 parts by weight of the polishing slurry composition. If the content of the cationic polymer is less than 0.0001 parts by weight compared to 100 parts by weight of the polishing slurry composition, the protective effect for the silicon nitride film is weakened, resulting in loss of the silicon nitride film, and if it exceeds 0.1 part by weight, the polishing rate for the silicon oxide film decreases. can do.

In one embodiment of the present application, the cationic compound may be added to implement a passivation role and an auto stop function of the silicon oxide film of the pattern wafer, and the cationic compound may be, for example, , a) Contains two or more nitrogen atoms in one molecule, b) Each nitrogen atom is connected by a single bond (C2~C3) alkylene and can rotate along the bond axis, c) Each nitrogen atom It may include a material selected from the group consisting of organic amine compounds having an average number of directly bonded carbon atoms (C/N avg.) of 2 to 3, salts thereof, and mixtures thereof. At this time, the amine compound is specifically tris[2-(isopropylamino)ethyl]amine, tris[2-(ethylamino)ethyl]amine, tris[2-(methylamino)ethyl]amine, 1,2- Bis(dimethylamino)ethane, N,N,N',N'-tetraethylethylenediamine, N,N'-diethyl-N,N'-diethylethylenediamine, N,N-diethyl-N', N'-dimethylethylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N, N'-bis(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-ethylethylenediamine, N,N-diethyl-N'-methylethylenediamine, N,N,N'-trimethylethylene Diamine, N,N,N'-triethylethylenediamine, N-ethyl-N'-methylethylenediamine, 1-(2-aminoethyl)pyrrolidine, 2-(2-(methylamino)-ethylamino) -ethanol, 1-(2-aminoethyl)piperidine, 4-(3-aminopropyl)morpholine, 4-(2-aminoethyl)morpholine, piperazine, 1-methylpiperazine, 2-methylpipe Razine, 1-ethylpiperazine, 1-isopropylpiperazine, 1-butylpiperazine, 1-(2-methoxyethyl)piperazine, 1-(2-ethoxyethyl)piperazine, 1,2,4 -Trimethylpiperazine, 2,3,5,6-tetramethylpiperazine, 1-(2-aminoethyl)piperazine, 1-(2-hydroxyethyl)piperazine, 1,4-dimethylpiperazine, 2 ,6-dimethylpiperazine, 2,5-dimethylpiperazine, 2-piperazinoethylamine, 1,4-bis(3-aminopropyl)piperazine, 1-[2-(dimethylamino)ethyl]piperazine , N,N'-bis-(2-hydroxyethyl)-2,5-dimethylpiperazine, 1,4-diazepane, 1-methyl-1,4-diazepane, 1,4-dimethyl-1, A substance selected from the group consisting of 4-diazepane, 1,4,7-triazacyclononane, 1,4,8,11-tetraazacyclotetradecane, diallyl dimethyl ammonium chloride (DADMAC), and combinations thereof It may include.

In one embodiment of the present application, the content of the cationic compound may be 0.01 to 2 parts by weight based on 100 parts by weight of the polishing slurry composition. If the content of the cationic compound is less than 0.01 parts by weight compared to 100 parts by weight of the polishing slurry composition, the auto stop function may not be implemented due to weakened passivation of the silicon oxide film, and if it exceeds 2 parts by weight. Step height polishing may not be achieved due to excessive passivation of the silicon oxide film.

In one embodiment of the present application, the nonionic surfactant may be added to improve the fluidity and uniformity of the polishing slurry composition, and the nonionic surfactant may be polyethylene glycol, polypropylene glycol, polyvinyl alcohol, or glycerin. It may contain a material selected from the group consisting of polyglycerin, polyvinylpyrrolidone, and combinations thereof.

In one embodiment of the present application, the content of the nonionic surfactant may be 0.01 parts by weight to 10 parts by weight based on 100 parts by weight of the polishing slurry composition. If the content of the nonionic surfactant is less than 0.01 parts by weight compared to 100 parts by weight of the polishing slurry composition, the viscosity of the polishing additive composition may be low and fluidity may be reduced, and if it exceeds 10 parts by weight, the dispersion stability of the abrasive may be impaired, thereby hindering the polishing process. Scratches may occur.

In one embodiment of the present application, the polishing accelerator may be added to improve the step removal ability of the polishing slurry, and the polishing accelerator is selected from the group consisting of polysaccharide compounds, polyol compounds, and combinations thereof. May contain substances. At this time, the polysaccharide compound is Glycolaldehyde, Glyceraldehyde, Dihydroxyacetone, Threose, erythrose, erythrulose, and ribose. , a polymer containing arabinose, xylose, fructose, glucose, galactose, mannose as monomers, and combinations thereof. It may contain substances, specifically sucrose, polygalacturonic acid, amylose, dextrin, isomaltotriose, cellopentaose, glycol chitosan. chitosan), xanthan gum, hydroxyethyl-cellulose, (Hydroxypropyl)methyl cellulose, agarose, and combinations thereof. It may contain a selected substance. In addition, the polyol compound may include a material selected from the group consisting of polyester-based polyols, polyether-based polyols, and combinations thereof, such as alginic acid, pectic acid, carboxymethylcellulose, agar, curdlan, and pullulan. .

In one embodiment of the present application, the content of the polishing accelerator may be 0.01 to 10 parts by weight based on 100 parts by weight of the polishing slurry composition. If the content of the polishing accelerator is less than 0.01 parts by weight compared to 100 parts by weight of the polishing slurry composition, the polishing acceleration effect may decrease and the step removal speed for the silicon oxide film may decrease, and if it exceeds 10 parts by weight, scratches may occur during the polishing process. The possibility may increase.

In one embodiment of the present application, the chemical mechanical polishing slurry composition may include deionized water (DIW). The deionized water is water from which all dissolved ions have been removed using an ion resin, and may be ultrapure water.

In one embodiment of the present application, the abrasive; dispersant; pH adjuster; When the weight ratio of the content of the polishing additive and the deionized water is 1:1 to 3, the chemical mechanical polishing slurry can be used in an ILD (Interlayer Dielectric) polishing process.

In one embodiment of the present application, the ILD (Interlayer Dielectric) polishing process polishes a patterned wafer having concave portions and convex portions, and as the polishing rate of the convex portions is higher than that of the concave portions, planarization can proceed effectively. When polishing the patterned wafer with the chemical mechanical polishing slurry composition, the polishing speed ratio of the concave portion and the convex portion may be 1:30 to 40.

In one embodiment of the present application, the abrasive; dispersant; pH adjuster; When the weight ratio of the content of the polishing additive and the deionized water is 1:5 to 10, the chemical mechanical polishing slurry can be used in an STI (Shallow Trench Isolation) polishing process.

In one embodiment of the present application, when the chemical mechanical polishing slurry composition is used in an STI (Shallow Trench Isolation) polishing process, the selectivity of the oxide film to the nitride film of the chemical mechanical polishing slurry composition may be 30 to 50.

In one embodiment of the present application, the chemical mechanical polishing slurry composition may be used in an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process depending on the content of deionized water. This may be because the concentration of each additive in the entire polishing slurry composition may vary depending on the content of deionized water, and when the concentration of the additive varies, the degree of passivation effect on the silicon oxide film and silicon nitride film may vary.

In one embodiment of the present application, it is known that polishing performance deteriorates when a general chemical mechanical polishing slurry composition is subjected to slurry aging, but the chemical mechanical polishing slurry composition is slurry aged for more than 2 weeks. Afterwards, the characteristics prior to slurry aging can be maintained. This is because, in the case of a general polishing slurry composition, the polishing slurry and additives are mixed immediately before polishing, the stability of the slurry composition may be reduced, and as a result, agglomeration of abrasive particles occurs over time, reducing polishing performance. It may be possible. Therefore, generally, polishing slurry is produced in a two-component form and goes through a process of mixing with additives right before polishing, but the chemical mechanical polishing slurry composition can ensure the stability of the slurry even when additives are applied to the polishing slurry, through which The polishing slurry can be used as a one-component slurry.

The second aspect of the present application is,

Provided is a polishing method characterized by performing an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process using the chemical mechanical polishing slurry composition according to the first aspect of the present application.

Detailed description of parts overlapping with the first aspect of the present application has been omitted, but the content described in the first aspect of the present application can be applied equally even if the description is omitted in the second aspect.

Hereinafter, the polishing method according to the second aspect of the present application will be described in detail.

In one embodiment of the present application, the chemical mechanical polishing method may include simultaneously polishing a silicon oxide film and a silicon nitride film using the chemical mechanical polishing slurry composition. The method of simultaneously polishing a silicon oxide film and a silicon nitride film using the slurry composition for polishing a silicon oxide film can be any conventional polishing method and condition, and is not particularly limited in the present invention. Therefore, detailed description thereof is omitted in this specification.

Additionally, the Interlayer Dielectric (ILD) polishing process and the Shallow Trench Isolation (STI) polishing process are conventionally commonly used polishing processes and are not particularly limited in the present invention. Therefore, detailed description thereof is omitted in this specification.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Example 1. Preparation of chemical mechanical polishing slurry composition

To evaluate the polishing performance of the chemical mechanical polishing slurry composition of the present invention, the chemical mechanical polishing slurry composition was prepared as follows.

First, 3 parts by weight of ceria particles with a size of 140 nm were mixed with 100 parts by weight of deionized water, and 2 parts by weight of picolinic acid was mixed with 100 parts by weight of ceria particles, and the pH was adjusted to 4 with acetic acid to prepare an abrasive.

Afterwards, as a polishing additive, polyetherimide (PEI) 0.01 wt%, diallyl dimethyl ammonium chloride (DADMAC) 0.1 wt%, polyethylene glycol (nonionic surfactant) 0.05 wt%, and sucrose (polishing accelerator) 0.1 wt% were added to the abrasive, and then ammonia water as a pH adjuster was added. The pH was adjusted to 6 using .

A chemical mechanical polishing slurry composition was prepared by mixing deionized water with the mixture at a weight ratio of 1:1.

Example 2-1. Preparation of chemical mechanical polishing slurry compositions

A chemical mechanical polishing slurry composition was prepared as in Example 1, except that the mixture and deionized water were mixed at a weight ratio of 1:3.

Example 2-2. Preparation of chemical mechanical polishing slurry compositions

A chemical mechanical polishing slurry composition was prepared in the same manner as in Example 2-1, except that the slurry composition prepared in Example 2-1 was aged for 2 weeks.

Example 3. Preparation of Chemical Mechanical Polishing Slurry Composition

A chemical mechanical polishing slurry composition was prepared as in Example 1, except that the mixture and deionized water were mixed at a weight ratio of 1:5.

Example 4-1. Preparation of chemical mechanical polishing slurry compositions

A chemical mechanical polishing slurry composition was prepared as in Example 1, except that the mixture and deionized water were mixed at a weight ratio of 1:10.

Example 4-2. Preparation of chemical mechanical polishing slurry compositions

A chemical mechanical polishing slurry composition was prepared in the same manner as in Example 4-1, except that the slurry composition prepared in Example 4-1 was aged for 2 weeks.

Comparative Example 1. Preparation of chemical mechanical polishing slurry composition

HC60 from Rhodia, which is commonly used as a polishing slurry composition, was prepared.

Comparative Example 2-1. Preparation of chemical mechanical polishing slurry compositions

We prepared PSS-C, a polishing slurry for STI (Shallow Trench Isolation) polishing process sold by our company.

Comparative Example 2-2. Preparation of chemical mechanical polishing slurry compositions

The same polishing slurry composition as Comparative Example 2-1 was used, except that the slurry composition was aged for 2 weeks.

Comparative Example 3-1. Preparation of chemical mechanical polishing slurry compositions

We prepared CST-S22, a polishing slurry for the ILD (Interlayer Dielectric) polishing process sold by our company.

Comparative Example 3-2. Preparation of chemical mechanical polishing slurry compositions

The same polishing slurry composition as Comparative Example 3-1 was used, except that the slurry composition was aged for 2 weeks.

Experiment example. Performance evaluation of chemical mechanical polishing slurry composition

To evaluate the performance of the chemical mechanical polishing slurry composition prepared in the above Examples and Comparative Examples, experiments were conducted under the following conditions, and the test results are shown in Table 1 below.

Polisher: Poli 400 (manufactured by G&P Technology)

Evaluation conditions: 3 psi

Wafer: 4 x 4 cm ² Plasma Enhanced Tetra Ethyl Ortho Silicate (PETEOS)

SKW3-2 pattern wafer(STI), SKW7-2 pattern wafer(ILD)

Slurry flow rate: 100 mL/min

Polishing pad: IC100 (Dow)

[Table 1]

As shown in Table 1, the polishing slurry composition of Example 1 (weight ratio of mixture and deionized water 1:1) and the polishing slurry composition of Example 2-1 (weight ratio of mixture and deionized water 1:3) were used. It was confirmed that during polishing, the ratio of the polishing speed of the convex portion to the polishing speed of the concave portion of the ILD (Interlayer Dielectric) pattern increased compared to Comparative Examples 1 to 5.

In addition, when aged for 2 weeks in Example 2-2, it was confirmed that there was little change in the polishing speed of the convex portion and the polishing rate of the concave portion of the ILD (Interlayer Dielectric) pattern compared to Example 2-1. .

Therefore, it was confirmed that the chemical mechanical polishing slurry composition when the weight ratio of the mixture and deionized water was 1:1 to 1:3 was suitable for the ILD (Interlayer Dielectric) polishing process and maintained its performance even after aging for 2 weeks.

Meanwhile, when polishing using the polishing slurry composition of Example 3 (weight ratio of mixture and deionized water 1:5) and the polishing slurry composition of Example 4-1 (weight ratio of mixture and deionized water 1:10), the nitride film It was confirmed that the selectivity of the oxide film was higher than that of the polishing slurry compositions of Comparative Examples 1, 2-1, and 2-2, and the collapse of the STI pattern nitride film and the dishing level of the STI (Shallow Trench Isolation) pattern were significantly lowered. was able to confirm.

In addition, when aged for 2 weeks in Example 4-2, the selectivity of the oxide film to the nitride film, the erosion of the STI (Shallow Trench Isolation) pattern nitride film, and the STI (Shallow Trench Isolation) pattern dishing level ( It was confirmed that the dishing level was almost the same as that of Example 4-1.

Therefore, it was confirmed that the chemical mechanical polishing slurry composition when the weight ratio of the mixture and deionized water is 1:5 to 1:10 is suitable for the STI (Shallow Trench Isolation) polishing process and maintains its performance even after aging for 2 weeks. .

Through this, it was confirmed that the chemical mechanical polishing slurry composition can be used in the ILD (Interlayer Dielectric) polishing process or STI (Shallow Trench Isolation) polishing process depending on the content of deionized water, and its performance was also confirmed to be excellent.

Claims (15)

Abrasives; dispersant; pH adjuster; polishing additives; and deionized water,
Depending on the content of the deionized water, it can be used in the ILD (Interlayer Dielectric) polishing process or STI (Shallow Trench Isolation) polishing process,
The polishing additive is a cationic polymer; cationic compounds; nonionic surfactants; And a polishing accelerator,
The polishing accelerator is selected from the group consisting of polysaccharide compounds, polyol compounds, and combinations thereof,
The abrasive has a primary particle size of 10 to 80 nm and a secondary particle size of 80 to 200 nm.
Chemical mechanical polishing slurry composition. According to paragraph 1,
A chemical mechanical polishing slurry composition wherein the abrasive is a metal oxide.
According to paragraph 2,
The metal oxide is selected from the group consisting of silica (SiO ₂ ), zirconia (ZrO ₂ ), alumina (Al ₂ O ₃ ), ceria (CeO ₂ ), titania (TiO ₂ ), germania (GeO ₂ ), and combinations thereof. A chemical mechanical polishing slurry composition comprising a selected material.
According to paragraph 1,
The dispersant is selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, serine, threonine, asparagine, glutamine, glycine, proline, alanine, valine, isoleucine, leucine, phenylalanine, betaine, and combinations thereof. A chemical mechanical polishing slurry composition comprising a material.
According to paragraph 1,
A chemical mechanical polishing slurry composition wherein the pH adjuster is a base material. According to paragraph 1,
The cationic polymer includes polyacrylamide-diallyl dimethyl ammonium chloride (P(AAm-co-DADMAC)), polyetherimide (PEI), poly diallyl dimethyl ammonium chloride (Poly(DADMAC)), and polyacrylamide (PAAM). ) and combinations thereof. According to paragraph 1,
The cationic compound a) contains two or more nitrogen atoms in one molecule, b) each nitrogen atom is connected to a single bond of (C2~C3) alkylene and can rotate along the bond axis, and c) each nitrogen atom is connected to a single bond (C2~C3) alkylene. A chemical mechanical polishing slurry composition comprising a material selected from the group consisting of organic amine compounds having an average number of directly bonded carbon atoms per atom (C/N avg.) of 2 to 3, salts thereof, and mixtures thereof. . According to paragraph 1,
A chemical mechanical polishing slurry composition wherein the nonionic surfactant includes a material selected from the group consisting of polyethylene glycol, polypropylene glycol, polyvinyl alcohol, glycerin, polyglycerin, polyvinylpyrrolidone, and combinations thereof. delete According to paragraph 1,
The abrasive; dispersant; pH adjuster; and a polishing additive; and when the weight ratio of the content of the deionized water is 1:1 to 3, the chemical mechanical polishing slurry is used in an ILD (Interlayer Dielectric) polishing process.
According to paragraph 1,
The abrasive; dispersant; pH adjuster; and a polishing additive; and when the weight ratio of the content of the deionized water is 1:5 to 10, the chemical mechanical polishing slurry is used in an STI (Shallow Trench Isolation) polishing process.
According to clause 10,
The ILD (Interlayer Dielectric) polishing process is to polish a pattern wafer having concave portions and convex portions,
When polishing the pattern wafer with the chemical mechanical polishing slurry composition, the ratio of the polishing speed of the concave portion and the convex portion is 1:30 to 40.
According to clause 11,
A chemical mechanical polishing slurry composition, wherein the selectivity ratio of the oxide film to the nitride film of the chemical mechanical polishing slurry composition used in the STI (Shallow Trench Isolation) polishing process is 30 to 50.
According to paragraph 1,
The chemical mechanical polishing slurry composition is characterized in that it can maintain the characteristics before slurry aging even after slurry aging for more than 2 weeks.
A polishing method comprising performing an ILD (Interlayer Dielectric) polishing process or an STI (Shallow Trench Isolation) polishing process using the chemical mechanical polishing slurry composition of claim 1.