KR20230056230A - Post-cmp cleaner composition - Google Patents

Abstract

The present invention relates to two or more ammonium salt-based chelating agents; phosphoric acid-based chelating agents; organic acids containing one or more carboxyl groups; fluorine-based compounds; anionic surfactant; and water.

Description

Cleaning liquid composition after CMP {POST-CMP CLEANER COMPOSITION}

The present invention relates to a post-CMP cleaning liquid composition, and relates to a post-CMP cleaning liquid composition capable of effectively removing polishing residues and contaminants generated in a polishing process without damaging the surface of a wafer after CMP.

In accordance with the recent decrease in semiconductor design rules, the importance of the quality of the polished surface is maximized when manufacturing submicron-scale semiconductor devices.

The chemical mechanical polishing (hereinafter referred to as “CMP”) process is also called a planarization process, and is a process that combines physical processes such as abrasion with chemical processes such as oxidation or chelation to obtain accurate patterning. means Specifically, the CMP process is performed by applying a polishing slurry composition having active chemical properties to a polishing pad that rubs the surface of a semiconductor wafer, and the abrasive particles included in the polishing slurry composition and the surface protrusions of the polishing pad By mechanically polishing the surface of the semiconductor wafer while causing mechanical friction with the surface, excess material used in layer formation can be effectively removed.

In particular, since the chemical components included in the polishing slurry composition selectively remove the surface of the semiconductor wafer while inducing a selective chemical reaction on the surface of the semiconductor wafer, more optimized and extensive planarization can be achieved.

Meanwhile, after the CMP process, contaminants, such as residues generated during various processing operations including multilayer film formation, etching, and CMP processes, or particles generated from the removed layer, are generated. These residues or contaminants cause wire damage during subsequent processes of forming metal wires or various structures, increase surface damage of structures, and cause poor electrical performance of semiconductor devices.

Therefore, a cleaning operation to remove these residues or contaminants is performed as an essential follow-up process after the CMP process.

Meanwhile, in the CMP process, a ceria-based slurry containing ceria abrasive particles capable of achieving a higher polishing rate for an insulator and minimizing oxide erosion is most commonly used compared to a silica-based slurry containing silica particles. there is.

However, the ceria-based slurry has a disadvantage in that it is not easy to remove during a subsequent cleaning process due to the oppositely charged zeta potential of ceria particles with respect to the surface of the silicon oxide layer and the silicon nitride layer. If a subsequent process is performed while such ceria-based slurry residues remain on the semiconductor wafer, another problem of short circuit and increase in electrical resistance is caused due to the residues.

Currently, as the most efficient wet cleaner for removing ceria-based slurry residue, a cleaner containing hydrofluoric acid (hydrofluoric acid, HF) and ammonia water (NH ₄ OH) is used. However, the hydrofluoric acid not only over-etches the silicon oxide film and other low-dielectric materials to a static level or higher during the cleaning process, but also additionally proceeds with a subsequent cleaning process to remove them so that the hydrofluoric acid does not remain. There is a problem that the number of process steps increases.

Therefore, there is a need to develop a post-CMP cleaning composition capable of preventing re-adsorption of contaminants generated in the post-CMP polishing process and realizing excellent cleaning power without damaging the surface of a semiconductor wafer, particularly a silicon oxide film.

Korean Patent Registration No. 620260

The present invention is intended to solve the above-described problems, and ceria abrasive particles, particle contamination, organic contamination, metal contamination, etc. remaining on the semiconductor without damaging the wafer surface after the CMP process using the ceria-based slurry can be effectively removed. It is intended to provide a post-CMP cleaning liquid composition that has good rinseability with water and can stably clean the surface of a semiconductor wafer in a short time.

According to one embodiment, the present invention

two or more ammonium salt-based chelating agents;

phosphoric acid-based chelating agents;

organic acids containing one or more carboxyl groups;

fluorine-based compounds;

anionic surfactant; and

It provides a post-CMP cleaning liquid composition comprising; water.

The pH of the post-CMP cleaning liquid composition of the present invention is preferably 5 to 7.

The post-CMP cleaning composition of the present invention includes a polyacrylic acid-based or sulfonic acid-based anionic surfactant, thereby effectively removing ceria and organic matter remaining after the polishing process using the ceria slurry, and at the same time lowering the zeta potential to prevent re-adsorption of contaminants. Therefore, defects of the polishing surface can be reduced. In particular, the post-CMP cleaning liquid composition of the present invention contains a fluorine-based compound that can be used as an etchant for silicon oxide films, thereby securing etching properties for silicon oxide films and lifting ceria and fine residual metal ions bonded to the semiconductor wafer surface. - Lift off to allow easy removal. When the cleaning liquid composition after CMP of the present invention is used, the cleaning effect can be maximized without damaging the wafer surface, and thus a semiconductor device with improved performance and reliability can be manufactured.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the contents of the above-described invention, so the present invention is limited to those described in the drawings. It should not be construed as limited.
1 is a graph showing etching evaluation results for a silicon oxide film of Experimental Example 2;
Figure 2 is a flow chart of the Buffing CMP process sequence.
3 is a flow chart showing the Touch CMP process sequence.
4 is a flow chart showing an isolation CMP process.

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

The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

On the other hand, in the specification of the present invention, pH can be measured at room temperature using a pH measuring device of Orion StarA215 model manufactured by Thermo, unless otherwise specified.

In addition, in the present specification, "Zeta potential" is an index indicating the degree of surface charge of colloidal abrasive particles suspended or dispersed in a medium (water and/or organic solvent), and is an indicator of the electric field external to the colloid. When is applied, the colloidal particles migrate (move) in the opposite direction to the sign of the surface potential. At this time, the particle movement speed is calculated considering the strength of the applied electric field and the hydrodynamic effect (viscosity of the solvent, permittivity), etc. is a figure that has been The zeta potential is an electrostatic charge value measured on the surface of an abrasive particle, and its magnitude is an indication of the tendency of the abrasive particle to repel other particles or surfaces having a similar charge. As the size of the zeta potential increases, the repulsive force between the two materials becomes stronger, so the degree of dispersion and retention of dispersion increases. , the particles aggregate with each other and the degree of dispersion is lowered. In the case of the cleaning liquid composition after CMP of the present invention, as the absolute value of the zeta potential exceeds 45 mV, the repulsive force between particles increases and the degree of dispersion is improved, so that excellent cleaning effects can be realized.

In the specification of the present invention, the zeta potential was measured by electroanalysis using ZEN2600 Zetasizer Nano Z (Malvern) for surface potential, and the greater the absolute value of the measured value, the greater the repulsive force between particles, so the cleaning effect is excellent.

Post-CMP cleaning liquid composition

The post-CMP cleaning liquid composition according to the present invention

two or more ammonium salt-based chelating agents;

phosphoric acid-based chelating agents;

organic acids containing one or more carboxyl groups;

fluorine-based compounds;

anionic surfactant; and water.

According to the research of the present inventors, by including a polyacrylic acid-based or sulfonic acid-based anionic surfactant, ceria and organic matter remaining after a polishing process using a ceria slurry can be effectively removed, and contaminant re-adsorption can be prevented by lowering the zeta potential. Therefore, defects of the polishing surface can be reduced. In particular, the post-CMP cleaning liquid composition of the present invention contains a fluorine-based compound instead of hydrofluoric acid as an essential component as an etchant, thereby securing etching properties for the silicon oxide film and lifting ceria and fine residual metal ions bonded to the semiconductor wafer surface. - Lift off to allow easy removal. Therefore, if the post-CMP cleaning composition (eg, post-CMP cleaning composition) of the present invention is used, the cleaning effect for contaminants can be maximized without damaging the wafer surface, thereby manufacturing a semiconductor device with improved performance and reliability. can

The post-CMP cleaning liquid composition of the present invention has an etching rate of 1 to 10 Å/min during cleaning, and excellent surface defect reduction of about 44% for silicon oxide films and about 93% for silicon nitride films compared to conventional cleaning compositions using hydrofluoric acid can have an effect.

The post-CMP cleaning liquid composition of the present invention can be used to effectively clean polishing residues after a CMP process for a semiconductor wafer comprising a silicon oxide film and optionally a silicon nitride film or polysilicon film.

At this time, the CMP process may include a buffing CMP process, a touch CMP process, or an isolation CMP process.

Specifically, referring to FIG. 2, the buffing CMP process may include all planarization processes performed for the purpose of forming an oxide film for insulation on a conductive pattern such as polysilicon and then removing a step or oxide film portion. there is.

Referring to FIG. 3, the Touch CMP process is a contaminant generated on the substrate surface after the CMP process, deposition process, or etching process, such as surface particles remaining on the surface of the polishing film, or contaminants generated during the deposition process. It may include all planarization processes performed to remove defects by removing embedded particles or the like or flattening a polished surface on which rip-out has occurred due to an etching process or the like.

In this case, the film to be polished may be at least one of an oxide film, a nitride film, and a polysilicon film.

Referring to FIG. 4, the isolation CMP process is a process for removing excessively deposited or formed films on the front surface of a semiconductor substrate, and specific examples include (a) an isolation process in which a nitride film is used as a polishing stop film and an oxide film is polished, or (b) a poly It may include an isolation process of polishing an oxide film using silicon as a polishing stop film.

Hereinafter, each component of the post-CMP cleaning composition (eg, post-CMP cleaning composition) of the present invention will be described in more detail.

(A) Ammonium salt-based chelating agent

The post-CMP cleaning liquid composition of the present invention includes two or more ammonium salt-based chelating agents.

The ammonium salt-based chelating agent may form a complex compound by forming a coordinate bond with ceria particles lifted off by an etchant or fine residual metal ions. Since the deactivated metal ions are readily soluble in the cleaning composition, they can be easily removed. Moreover, since the ammonium salt-based chelating agent acts as a pH buffer due to the ammonium salt component and can prevent a rapid change in pH of the cleaning solution composition after CMP, it prevents re-adsorption of residual abrasive particles and contaminants, effectively preventing defects on the surface of semiconductor wafers. can be improved

The ammonium salt-based chelating agent may include an organic acid containing an ammonium salt, and representative examples thereof include ammonium citrate, ammonium oxalate, ammonium carbonate, ammonium acetate, and ammonium phosphate. (Ammonium Phosphate), ammonium sulfate (Ammonium Sulfate), ammonium benzoate (Ammonium Benzonate) and ammonium bicarbonate (Ammonium Bicarbonate) may include at least two or more selected from the group consisting of, more specifically, the ammonium salt-based chelating agent is ammonium citrate , It may include at least two or more selected from the group consisting of ammonium oxalate, ammonium carbonate, ammonium acetate and ammonium phosphate. Preferably, the first chelating agent may include two or more compounds selected from the group consisting of ammonium citrate, ammonium carbonate, ammonium acetate, and ammonium phosphate.

The ammonium salt-based chelating agent may be included in an amount of 0.5% to 10% by weight, specifically 2% to 9% by weight based on the total weight of the cleaning liquid composition after CMP.

When the ammonium salt-based chelating agent is included within the above range, sufficient chelating components capable of reacting with metal ions can be secured, so that ceria particles and other polishing by-products can be effectively removed, and rapid pH change of the cleaning solution composition after CMP can be suppressed. Therefore, it is possible to prevent ceria particles and other polishing by-products from being precipitated, and thus, it is possible to effectively improve the occurrence of defects on the surface of a semiconductor wafer.

(B) Phosphoric acid-based chelating agent

The post-CMP cleaning liquid composition of the present invention includes at least one phosphoric acid-based chelating agent.

Like the ammonium salt-based chelating agent, the phosphoric acid-based chelating agent forms a complex compound with the lifted-off ceria or the remaining metal ions through a coordination bond, so that metal ions can be easily removed.

The phosphoric acid-based chelating agent is a compound containing a phosphate group or a phosphonic acid group, which is a phosphoric acid-based organic acid, in its molecular structure, and representative examples thereof include ethylidenediphosphonic acid, 1-hydroxyethylidene-1,1'-diphosphonic acid ( 1-hydroxy ethylidene-1,1-diphosphoric acid; HEDP), 1-hydroxypropylidene-1,1'-diphosphonic acid, 1-hydroxybutylidene-1,1'-diphosphonic acid, ethylamino Bis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), 2-phosphono-butane-1,2,4-tricarboxylic acid, nitrilotris(methylenephosphonic acid), ethylenediaminebis(methylenephosphonic acid) Phosphonic acid), 1,3-propylenediamine bis(methylenephosphonic acid), ethylenediamine tetra(methylene phosphoric acid), EDTMPA, ethylenediaminetetra(ethylenephosphonic acid), 1,3- Propylenediaminetetra (methylenephosphonic acid), 1,2-diaminopropanetetra (methylenephosphonic acid), 1,6-hexamethylenediaminetetra (methylenephosphonic acid), hexenediaminetetra (methylenephosphonic acid), diethylenetriamine Penta(methylenephosphonic acid), diethylenetriaminepentakis(methylphosphonic acid), N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(ethylenephosphonic acid), tri Ethylenetetraminehexa(methylenephosphonic acid), triethylenetetraminehexa(ethylenephosphonic acid), hydrogen phosphate, diammonium hydrogen phosphate, triammonium hydrogen phosphate Consisting of monobutyl phosphate, monoamyl phosphate, monononyl phosphate, monocetyl phosphate, monophenyl phosphate and monobenzyl phosphate It may include one or more compounds selected from the group, specifically two or more compounds.

The phosphoric acid-based chelating agent may be included in an amount of 0.1 wt% to 5 wt%, specifically 0.1 wt% to 3.0 wt%, based on the total weight of the cleaning liquid composition after CMP.

When the phosphoric acid-based chelating agent is included within the above range, ceria particles and other polishing by-products can be effectively removed by sufficiently securing a chelate component capable of reacting with metal ions, and thus surface defects can be effectively improved. In addition, it is possible to suppress a rapid change in pH of the cleaning solution composition after CMP, thereby preventing ceria particles and other polishing by-products from being precipitated, thereby reducing defects on the surface of the semiconductor wafer.

(C) organic acid

The post-CMP cleaning liquid composition of the present invention may contain one or more organic acids containing at least two carboxy groups.

The organic acid is a substance that contributes to dissolving the oxidized conductive material in the cleaning solution and can be used as a metal oxide solubilizer.

The organic acid can improve the solubility of ceria in the cleaning liquid by oxidizing the ceria particles while adsorbing one or more to two carboxy group (-COOH) moieties on the surface of the ceria abrasive particles, thereby increasing the removal efficiency. That is, as shown in Scheme 1 below, the organic acid included as a solubilizing agent is dissolved to supply H ⁺ ions and electrons "e", and the supplied electrons are used in the ceria reduction reaction as shown in Scheme 2 below to obtain reduced Ce(III) ions. generate Thereafter, the reduced Ce(III) ions are dissolved into Ce(OH) ₃ by hydration and can be easily dissolved in the cleaning composition and removed.

[Scheme 2]

R-COOH → R-COO ^- + H ⁺ + e

[Scheme 3]

Ce(IV)+e → Ce(III)

Representative examples of the organic acid include at least one selected from the group consisting of citric acid, lactic acid, gluconic acid, maleic acid, malic acid, and oxalic acid. It may include, and specifically, the organic acid may include at least one selected from the group consisting of citric acid, lactic acid, gluconic acid, and oxalic acid.

The organic acid may be included in an amount of 0.5 wt% to 10 wt%, specifically 0.5 wt% to 8.0 wt%, or 0.5 wt% to 5 wt% based on the total weight of the cleaning liquid composition after CMP.

When the organic acid is included in the above range, the supply of H ⁺ ions and electrons "e" is smooth, so that the ceria reduction reaction can be easily performed, thereby preventing the problem of precipitation of ceria particles due to the decrease in solubility in the cleaning solution. can

(D) fluorine-based compounds

The post-CMP cleaning liquid composition of the present invention may include a fluorine-based compound as an etchant instead of hydrofluoric acid as an essential component.

Since the fluorine-based compound contains fluorine ions, it serves to etch the surface of the silicon oxide film and at the same time lift-off ceria particles or fine residual metal ions bonded to the surface of the semiconductor wafer (see Scheme 3 below).

[Scheme 3]

As a representative example, the fluorine-based compound may include at least one fluorine-based compound selected from the group consisting of ammonium fluoride, ammonium bifluoride, and tetramethylammonium fluoride (TMAF), , more specifically ammonium fluoride.

The fluorine-based compound may be included in an amount of 2.0 wt % to 15 wt % based on the total weight of the cleaning liquid composition after CMP.

When the fluorine-based compound is included in an amount less than the above range, the etching rate of the silicon oxide film is rapidly reduced due to lack of fluorine ions, and the lift-off effect may be insignificant. In addition, when the fluorine-based compound is contained in excess of the above range, an overetching phenomenon occurs due to an increase in the etching rate of the silicon oxide film during cleaning, and the roughness of the surface of the silicon oxide film increases, thereby increasing the occurrence of surface defects can do.

Preferably, the fluorine-based compound may be included in an amount of 2.0 wt% to 10 wt%, specifically 3.0 wt% to 8.0 wt%, based on the total weight of the cleaning liquid composition after CMP.

(E) anionic surfactant

The post-CMP cleaning liquid composition of the present invention may include an anionic surfactant as a surface modifier.

Since the anionic surfactant can be adsorbed on the surface of the semiconductor wafer to change the surface potential of the semiconductor wafer to a negative value, re-adsorption of slurry particles after cleaning can be prevented. For example, when the anti-polish film of the semiconductor wafer is made of a silicon oxide film or a silicon nitride film, since it has a positive potential, metal particles and the like are re-adsorbed, making it vulnerable to contamination. Therefore, when the surface of the anti-polishing film is modified to have a negative potential using an anionic surfactant, the zeta potential (-mV) value is lowered to a negative value, thereby reducing adsorption of contaminants.

Representative examples of the anionic surfactant include polyacrylic acid (PAA)-based compounds, polyacrylic acid ammonium salt-based compounds, polyacrylic maleic acid, sulfonic acid-based compounds, sulfonate-based compounds, sulfonic acid ester-based compounds, sulfonic acid ester salt-based compounds, and acrylic/styrene copolymers. , Polyacrylic acid/styrene copolymer, polyacrylamide/acrylic acid copolymer, polyacrylic acid/sulfonic acid copolymer, and polyacrylic acid/maleic acid copolymer. Specifically, the anionic surfactant may include at least one of a polyacrylic acid-based compound and a sulfonic acid-based compound.

The sulfonic acid compound is a group consisting of alkyl aryl sulfonates, alkyl ether sulfonates, alkyl sulfonates, aryl sulfonates, polystyrene sulfonates, alkane sulfonates, alpha-olefin sulfonates, dodecylbenzene sulfonates and alkylbenzene sulfonates. It may include at least one selected from.

The anionic surfactant may be included in an amount of 1.0 wt% to 10 wt%, specifically 1.0 wt% to 8 wt% based on the total weight of the cleaning liquid composition after CMP.

When the anionic surfactant is included within the above range, surface modification of the anti-polishing film is facilitated, and the concentration of the cleaning composition after CMP is adjusted to prevent the cleaning composition from becoming cloudy.

(F) water

The post-CMP cleaning liquid composition of the present invention may contain water as a solvent capable of controlling the ease of pH adjustment, handling, safety, reactivity with the polishing surface, and the like.

Deionized water, ion-exchanged water, ultrapure water, etc. may be used as the water, and among these, ultrapure water filtered through an ion exchange resin is preferable.

The water may be included in the remaining amount of the cleaning liquid composition after CMP, and unless otherwise specified, in the cleaning liquid composition after CMP, (A) an ammonium salt-based chelating agent, (B) a phosphoric acid-based chelating agent, (C) an organic acid, ( D) fluorine-based compound and (E) all of the remainder except for the content of the anionic surfactant may be water.

Meanwhile, the pH of the cleaning liquid composition after CMP of the present invention is preferably 4 to 7, specifically 5 to 6.

When the pH of the cleaning liquid composition after CMP of the present invention satisfies the above range, an excellent cleaning effect can be realized.

Specifically, when the pH of the cleaning liquid composition after CMP is 4 or less, the Zeta potential increases to a positive value (+mV), so that the surface of the anti-polish film, for example, silicon nitride film is not modified, and particles are re-adsorbed, resulting in surface defects. cause an increase In addition, when the pH of the cleaning liquid composition after CMP is 7 or more, the action of the fluorine-based compound as an etchant and the reduction reaction of ceria [Ce(IV)+e→Ce(III)] are caused by a decrease in hydrogen ion (H+) concentration. Since it does not occur, it becomes a cause of surface defect increase.

(G) pH adjusting agent

The post-CMP cleaning liquid composition of the present invention may optionally include a pH adjusting agent in order to maintain the pH range described above.

The pH adjusting agent is not involved in the performance of the cleaning liquid composition after CMP, but as a component capable of adjusting the optimal pH, a basic compound containing both a primary amine group and a primary alcohol group may be used. As a representative example, the pH adjusting agent may include at least one selected from the group consisting of ammonia, ammonium methyl propanol (AMP), monoethanolamine, triethanolamine (MEA), and tromethamine, and specifically monoethanol amines or triethanolamines.

The pH adjusting agent may be included in an appropriate amount so that the post-CMP cleaning liquid composition of the present invention can achieve excellent cleaning effect while maintaining the above pH range. For example, the pH adjusting agent may be included in the range of 0.5 to 10% by weight in the cleaning liquid composition after CMP.

As described above, the post-CMP cleaning liquid composition of the present invention is performed after the CMP process using the ceria slurry composition, effectively removing ceria and organic substances remaining after polishing, and at the same time lowering the zeta potential of the substrate surface to negative to prevent re-adsorption of contaminants. Therefore, it is possible to reduce the defects of the polishing surface. In addition, it has good rinseability with water, can stably clean the surface of a semiconductor wafer in a short time, and has a slight silicon oxide film etching function. The effect can be maximized by cleaning method. Therefore, a semiconductor device with improved performance and reliability can be realized by applying the post-CMP cleaning liquid composition of the present invention.

Hereinafter, the present invention will be described in detail with reference to the following Examples and Comparative Examples. However, the technical spirit of the present invention is not limited or limited thereby.

Example

Examples 1 to 13.

According to the composition of Table 1 below, the post-CMP cleaning composition of Examples 1 to 13 was prepared by adding an ammonium salt-based chelating agent, a phosphoric acid-based chelating agent, an organic acid, a fluorine-based compound, and an anionic surfactant to water. At this time, the pH of the cleaning composition after CMP of Examples 1 to 10 can be adjusted by adding a pH adjusting agent (monoethanolamine; MEA).

In addition, the zeta potential of the cleaning composition after CMP was measured using an electroanalysis method using ZEN2600 Zetasizer Nano Z (Malvern Co.), and the results are shown in Table 1 below. At this time, as the absolute value of the measured value increases, the repulsive force between the particles increases, and the cleaning effect is excellent.

In Table 1 above, the abbreviations mean the following.

DI: distilled water

AC: Ammonium Citrate

AP: Ammonium Phosphate

EDTMPA: Ethylenediaminetetra (methylenephosphonic acid)

HEDP: 1-hydroxy ethylidene-1,1'-diphosphonic acid

OXA: Oxalic acid

CTA: Citric acid

AF: Ammonium fluoride

MEA: Monoethanolamine

comparative example

Comparative Examples 1 to 7

According to the composition of Table 2 below, the post-CMP cleaning composition of Examples 1 to 13 was prepared by adding an ammonium salt-based chelating agent, a phosphoric acid-based chelating agent, an organic acid, a fluorine-based compound, and an anionic surfactant to water. At this time, the pH of the cleaning composition after CMP of Comparative Examples 1 to 7 can be adjusted by adding a pH adjusting agent (monoethanolamine; MEA).

In addition, the zeta potential of the cleaning composition after CMP was measured using an electroanalysis method using ZEN2600 Zetasizer Nano Z (Malvern Co.), and the results are shown in Table 2 below.

In Table 2 above, the abbreviations mean the following.

DI: distilled water

AC: Ammonium Citrate

AP: Ammonium Phosphate

EDTMPA: Ethylenediaminetetra (methylenephosphonic acid)

HEDP: 1-hydroxy ethylidene-1,1'-diphosphonic acid

OXA: Oxalic acid

CTA: Citric acid

AF: Ammonium fluoride

MEA: Monoethanolamine

Experimental example

Experimental Example 1. Detergency evaluation experiment

A Si wafer on which a multilayer film including a silicon oxide film and a silicon nitride film is deposited is mounted in a CMP equipment (KCTECH, Elastic NT), and then CMP is performed for 30 seconds at 1 psi at 60 rpm using a CMP slurry composition (KCTECH, KCS3100) process proceeded.

After the CMP process was completed, the Si wafer on which the CMP process was completed was put into a cleaning box PVA brush cleaning box (Brushtek Co.) equipment, and a cleaning process was performed for 7 seconds using HF in Brush 1.

Then, in Brush 2, i) the cleaning liquid composition after CMP prepared in Examples 1 to 10, ii) the cleaning liquid composition after CMP prepared in Comparative Examples 1 to 7, and iii) a commercially available cleaning liquid, a reference example (SC-1 (Standard Clean-1, ammonia:hydrogen peroxide:water = 1:1:5 weight ratio, APM) was used to perform an additional cleaning process for 30 seconds each, washed with deionized water, and then dried by injecting nitrogen gas.

Then, the removal of residues and contaminants on the surface of the Si wafer was measured using an inspection equipment (SP2XP (KLA)), and the results are shown in Table 3 below.

At this time, in the case of the silicon oxide film, residues and contaminants having a diameter of 63 nm or more were evaluated as defects, and in the case of the silicon nitride film, residues and contaminants having a diameter of 52 nm or more were evaluated as defects.

[Evaluation results]

×: When 1,000 or more defects are measured on each film surface

△: When 500 to 1,000 defects are measured on each film surface

○: When less than 500 defects are measured on each film surface

Silicon Oxide (≥63nm) Silicon Nitride (≥52nm) number of defects defect change rate
(%) result number of defects defect change rate
(%) result reference example 646 - △ 3,064 - X Example 1 422 - 34.7% O 498 - 83.7% O Example 2 133 - 79.4% O 319 - 89.6% O Example 3 360 - 44.3% O 217 - 92.9% O Example 4 612 - 5.3% △ 370 - 87.9% O Example 5 444 - 31.3% O 255 - 91.7% O Example 6 339 -47.5% O 412 - 86.6% O Example 7 122 - 81.1% O 950 - 69.0% △ Example 8 225 - 65.2% O 887 - 71.1% △ Example 9 377 - 41.6% O 562 - 81.7% △ Example 10 512 - 20.7% △ 356 - 88.4% O Comparative Example 1 1,382 113.9% X 2,505 - 18.2% X Comparative Example 2 1,672 158.8% X 1,002 - 67.3% X Comparative Example 3 1,114 72.4% X 1,152 - 62.4% X Comparative Example 4 2,382 268.7% X 760 - 75.2% △ Comparative Example 5 815 26.2% △ 211 - 93.1% O Comparative Example 6 2,254 248.9% X 237 - 92.3% O Comparative Example 7 2,453 279.7% X 252 - 91.8% O

Referring to Table 3, when the cleaning composition after CMP of Examples 1 to 10 of the present invention is used, compared to the case of using the cleaning composition after CMP of Reference Example and Comparative Examples 1 to 7, the silicon oxide film and the silicon nitride film It can be seen that the defect change rate is significantly improved on all surfaces.

Experimental example 2. Silicon oxide film etching evaluation experiment

After washing the oxide film wafer with an area of 2 × 2 cm by spraying distilled water, it was dried and the pre-thickness (PRE-thickness) of the oxide film wafer was measured using a reflectometer (Reflectometer, Filmmetrics Co.).

Subsequently, the oxide film wafer was dipped in each of the post-CMP cleaning composition of Examples 2 and 7 and the post-CMP cleaning composition of Comparative Examples 3 and 6 at room temperature (25±5° C.) or 60° C. for 60 minutes.

Then, the oxide film wafer was taken out, washed with distilled water, dried, and the post thickness was measured.

The etch rate was calculated using the following [Equation 1], and the results are shown in Table 4 and FIG. 1 below.

[Equation 1]

Etchrate (Å/min) = {pre-thickness (Å) - post-thickness (Å)}/immersion time (min)

Fluorine-based compound content (%) in the cleaning liquid composition after CMP Etch rate (Å/min) Room temperature (25±5℃) 60℃ Example 2 5 5.3 44.6 Example 7 10 9.4 77.9 Comparative Example 3 0 0.0 0.0 Comparative Example 6 One 1.0 8.4

Referring to Table 4 and FIG. 1, it can be seen that the etching rate of the oxide film wafer also increased in proportion to the content of the fluorine-based compound contained in the cleaning liquid composition after CMP.

Specifically, the etching rate of the oxide film wafer of the cleaning liquid composition after CMP of Example 7 having the highest fluorine-based compound content in the cleaning liquid composition after CMP was the highest, whereas Comparative Example 3 in which the fluorine-based compound was not included in the cleaning liquid composition after CMP In the case of the cleaning liquid composition after CMP of , etching of the oxide film wafer was not performed at all, and in the case of the cleaning liquid composition after CMP of Comparative Example 6 containing 1% by weight of a fluorine-based compound, etching of the oxide film wafer was carried out as in Example 2 and It can be seen that it is lower than that of the cleaning liquid composition after CMP of 7.

Referring to the above results, it can be seen that the desired etching rate of the silicon oxide film can be controlled by adjusting the content of the fluorine-based compound in the cleaning liquid composition after CMP.

Claims (16)

two or more ammonium salt-based chelating agents;
phosphoric acid-based chelating agents;
organic acids containing one or more carboxyl groups;
fluorine-based compounds;
anionic surfactant; and
A post-CMP cleaning liquid composition comprising water;
The method of claim 1,
The ammonium salt-based chelating agent is at least two or more selected from the group consisting of ammonium citrate, ammonium oxalate, ammonium carbonate, ammonium acetate, ammonium phosphate, ammonium sulfate, ammonium benzoate and ammonium bicarbonate.
The method of claim 1,
The ammonium salt-based chelating agent is included in 0.5% to 10% by weight based on the total weight of the cleaning liquid composition after CMP.
The method of claim 1,
The phosphoric acid-based chelating agent is ethylidenediphosphonic acid, 1-hydroxy ethylidene-1,1'-diphosphonic acid, 1-hydroxypropylidene-1,1'-diphosphonic acid, 1-hydroxybutylly Den-1,1'-diphosphonic acid, ethylaminobis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), 2-phosphono-butane-1,2,4-tricarboxylic acid, nitrilo Tris(methylenephosphonic acid), ethylenediaminebis(methylenephosphonic acid), 1,3-propylenediaminebis(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), ethylenediaminetetra(ethylenephosphonic acid), 1,3 -Propylenediaminetetra (methylenephosphonic acid), 1,2-diaminopropanetetra (methylenephosphonic acid), 1,6-hexamethylenediaminetetra (methylenephosphonic acid), hexenediaminetetra (methylenephosphonic acid), diethylenetri Aminepenta (methylenephosphonic acid), diethylenetriaminepentakis (methylphosphonic acid), N,N,N',N'-ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (ethylenephosphonic acid), Triethylenetetraminehexa(methylenephosphonic acid), triethylenetetraminehexa(ethylenephosphonic acid), hydrogen phosphate, diammonium hydrogen phosphate, triammonium hydrogen phosphate, monobutyl phosphate, monoamyl phosphate, monononyl phosphate, A post-CMP cleaning liquid composition that is at least one selected from the group consisting of monocetyl phosphate, monophenyl phosphate and monobenzyl phosphate.
The method of claim 1,
The phosphoric acid-based chelating agent is included in 0.1% to 5% by weight based on the total weight of the cleaning liquid composition after CMP.
The method of claim 1,
The organic acid is at least one selected from the group consisting of citric acid, lactic acid, gluconic acid, maleic acid, malic acid and oxalic acid.
The method of claim 1,
The organic acid is included in 1.0% to 10% by weight based on the total weight of the cleaning liquid composition after CMP.
The method of claim 1,
The fluorine-based compound is at least one selected from the group consisting of ammonium fluoride, ammonium bifluoride and tetramethylammonium fluoride.
The method of claim 1,
The fluorine-based compound is included in 2.0% to 15% by weight based on the total weight of the cleaning liquid composition after CMP.
The method of claim 1,
The anionic surfactant is a polyacrylic acid (PAA)-based compound, polyacrylic acid ammonium salt-based compound, polyacrylic maleic acid, sulfonic acid-based compound, sulfonate-based compound, sulfonic acid ester-based compound, sulfonic acid ester salt-based compound, acrylic / styrene copolymer, polyacrylic acid / A styrene copolymer, a polyacrylamide / acrylic acid copolymer, a polyacrylic acid / sulfonic acid copolymer, and a polyacrylic acid / maleic acid copolymer, which is at least one selected from the group consisting of a post-CMP cleaning liquid composition.
The method of claim 1,
The anionic surfactant is a post-CMP cleaning liquid composition comprising at least one of a polyacrylic acid-based compound and a sulfonic acid-based compound.
The method of claim 1,
The anionic surfactant is included in 1.0% to 10% by weight based on the total weight of the cleaning liquid composition after CMP.
The method of claim 1,
The post-CMP cleaning composition further comprises a pH adjusting agent.
The method of claim 13,
The pH adjusting agent is a post-CMP cleaning liquid composition comprising a compound containing both a primary amine group and a primary alcohol group.
The method of claim 13,
The pH adjusting agent is a post-CMP cleaning liquid composition comprising at least one selected from the group consisting of ammonia, ammonium methylpropanol, monoethanolamine, triethanolamine and tromethamine.
The method of claim 1,
The pH of the cleaning liquid composition after CMP is 5 to 7, the cleaning liquid composition after CMP.

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