Chemical mechanical polishing cleaning fluid composition

Abstract

The present invention provides a post-chemical mechanical polishing (CMP) cleaning liquid composition, which comprises: two or more ammonium salt chelating agents; a phosphoric acid chelating agent; an organic acid containing one or more carboxyl groups; a fluorine compound; an anionic surfactant; and water, thereby being able to effectively remove polishing residues and pollutants generated in the polishing process.

Description

Technical Field

[0001] The present invention relates to a post-chemical mechanical polishing cleaning liquid composition, in particular to a post-chemical mechanical polishing cleaning liquid composition which can effectively remove polishing residues and pollutants generated in the polishing process without damaging the surface of a wafer after chemical mechanical polishing. Background Art

[0002] Recently, as semiconductor design rules are reduced, the importance of polished surface quality will reach its highest level when manufacturing sub-micron semiconductor devices.

[0003] The chemical mechanical polishing (hereinafter referred to as "CMP") process may also be referred to as a planarization process, which is a process that combines physical processes such as abrasion and chemical processes such as oxidation or chelation in order to achieve precise patterning. Specifically, the CMP process is performed by combining a polishing slurry composition having active chemical properties with a polishing pad that rubs the surface of a semiconductor wafer, and the abrasive particles contained in the polishing slurry composition and the surface protrusions of the polishing pad mechanically rub against the surface of the semiconductor wafer to mechanically polish the surface of the semiconductor wafer, thereby effectively removing excess substances used in layering.

[0004] In particular, the chemical components contained in the polishing slurry composition induce a selective chemical reaction on the surface of the semiconductor wafer to selectively remove the surface of the semiconductor wafer, thereby achieving more optimized and wider range planarization.

[0005] On the one hand, after the CMP process, there are contaminants caused by particles caused by residues generated during various processing operations such as multilayer film formation, etching and CMP processes or removed layers. These residues or contaminants become the cause of poor electrical performance of semiconductor devices, such as wiring damage and aggravated structural surface damage in subsequent processes for forming metal wiring or various structures. Therefore, after the CMP process, performing a cleaning operation to remove the residues or contaminants is an essential subsequent process.

[0006] On the other hand, when performing a CMP process, a cerium oxide slurry containing cerium oxide abrasive grains is most commonly used, which can achieve a faster insulator polishing rate and minimize oxide erosion, compared with a silicon oxide slurry containing silica particles.

[0007] However, the cerium oxide slurry has the following disadvantages: since the cerium oxide particles carry a zeta potential with opposite charges to the surfaces of the silicon oxide film and the silicon nitride film, it is difficult to remove in the subsequent cleaning process. If the subsequent process is performed in a state where such cerium oxide slurry residues remain on the semiconductor wafer, other problems such as short circuits and increased resistance may occur due to the residues.

[0008] Currently, hydrofluoric acid (HF) and ammonia (NH 4 OH) is used as the most effective wet cleaning agent for removing the residue of cerium oxide slurry. However, during the cleaning process, the hydrofluoric acid not only over-etches the silicon oxide film and other low-dielectric materials to above the static level, but also requires a subsequent cleaning process for removing the hydrofluoric acid to prevent the hydrofluoric acid from remaining, thus increasing the process cost and the number of process steps.

[0009] Therefore, it is practically necessary to develop a post-CMP cleaning liquid composition that can prevent the re-adsorption of contaminants generated in the post-CMP polishing process and exhibit excellent cleaning ability without damaging the surface of the semiconductor wafer (especially the silicon oxide film).

[0010] (Prior art literature)

[0011] (Patent Document)

[0012] Patent Document 1: Korean Patent Publication No. 620260 Summary of the invention

[0013] (Problems to be solved by the invention)

[0014] The present invention is proposed to solve the above-mentioned problems, and its purpose is to provide the following post-chemical mechanical polishing cleaning liquid composition: that is, after the chemical mechanical polishing process using cerium oxide slurry, the residual cerium oxide abrasive particles or particle contamination, organic contamination and metal contamination, etc. can be effectively removed without damaging the surface of the semiconductor wafer, and the post-chemical mechanical polishing cleaning liquid composition has good water rinsing properties and can stably clean the surface of the semiconductor wafer in a short time.

[0015] (Measures taken to solve the problem)

[0016] According to an implementation example, the present invention provides a post-chemical mechanical polishing cleaning liquid composition, which includes: two or more ammonium salt chelating agents; a phosphate chelating agent; an organic acid containing one or more carboxyl groups; a fluorine compound; an anionic surfactant; and water.

[0017] The pH of the post-CMP cleaning solution composition of the present invention is preferably 5 to 7.

[0018] (Effects of the Invention)

[0019] In the chemical mechanical polishing cleaning liquid composition of the present invention, as an anionic surfactant, a polyacrylic acid or sulfonic acid anionic surfactant is included, thereby effectively removing the cerium oxide and organic matter remaining after the grinding process using cerium oxide slurry, and the Zeta potential can be reduced to prevent the re-adsorption of pollutants, thereby reducing the defects of the grinding surface. In particular, in the chemical mechanical polishing cleaning liquid composition of the present invention, as an etchant, a fluorine compound is included to replace hydrofluoric acid, thereby ensuring the etching property for the silicon oxide film, and the cerium oxide and fine residual metal ions bound to the surface of the semiconductor wafer are stripped (lifted off) and easily removed. If the chemical mechanical polishing cleaning liquid composition of the present invention as described above is used, the cleaning effect can be maximized without damaging the surface of the semiconductor wafer, so that a semiconductor device with improved performance and reliability can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following drawings attached to this specification are examples of preferred embodiments of the present invention, which serve to make the technical concept of the present invention more understandable when combined with the above invention content. Therefore, the present invention should not be interpreted as being limited to the matters recorded in the drawings.

[0021] Figure 1 Graph showing the etching evaluation results of the silicon oxide film in Experimental Example 2.

[0022] Figure 2 The figure is a flow chart showing the process flow of chemical mechanical polishing (Buffing).

[0023] Figure 3 FIG. 1 is a flow chart showing the process flow of the touch chemical mechanical polishing process.

[0024] Figure 4 FIG. 1 is a flow chart showing an isolation chemical mechanical polishing process. DETAILED DESCRIPTION

[0025] Hereinafter, the present invention will be described in more detail.

[0026] The terms or words used in this specification and claims should not be interpreted as limited to the commonly understood or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical ideas of the present invention, based on the principle that the inventor can appropriately define the concepts of the terms in order to explain his invention in the most preferred manner.

[0027] On the other hand, in the specification of the present invention, pH can be measured at room temperature using an Orion Star A215 pH measuring device manufactured by Thermo Fisher Scientific, unless otherwise specified.

[0028] In addition, in this specification, Zeta potential is an index indicating the degree of surface charge of colloid abrasive particles suspended or dispersed in a medium (water and / or organic solvent). When an electric field is applied to the colloid from the outside, the colloid particles migrate (move) in a direction opposite to the sign of their surface potential. At this time, it is a value calculated by considering the electric field strength and fluid dynamic effects (viscosity and dielectric constant of the solvent) applied to the particle movement speed. The Zeta potential is the static charge value measured on the surface of the abrasive particles, and its magnitude is a value indicating the tendency of the abrasive particles to repel other particles or surfaces with similar charges. The larger the Zeta potential is, the stronger the repulsion between the two substances is, so the dispersion and dispersion retention become higher. Conversely, when the absolute value of the Zeta potential is close to 0, the electrostatic attraction between the particles promotes coagulation and sedimentation, the particles coagulate each other, and the dispersion decreases. For the post-chemical mechanical polishing cleaning liquid composition of the present invention, the absolute value of the Zeta potential is greater than 45mV, so the repulsion between the particles is increased, the dispersion is improved, and thus an excellent cleaning effect can be presented.

[0029] In the present specification, the surface potential of the Zeta potential is measured by electroanalysis using a ZEN2600 Zetasizer Nano Z (Malvern), and the larger the absolute value of the measured value, the greater the repulsive force between particles, and thus the better the cleaning effect.

[0030] Chemical mechanical polishing cleaning fluid composition

[0031] The post-chemical mechanical polishing cleaning liquid composition of the present invention comprises: two or more ammonium salt chelating agents; a phosphoric acid chelating agent; an organic acid containing one or more carboxyl groups; a fluorine compound; an anionic surfactant; and water.

[0032] According to the research of the present inventors, when the anionic surfactant includes polyacrylic acid or sulfonic acid anionic surfactant, the residual cerium oxide and organic matter etc. after the grinding process can be effectively removed using cerium oxide slurry, while the Zeta potential is reduced to prevent the re-adsorption of pollutants, so the defects of the grinding surface can be reduced. Especially, in the cleaning liquid composition after chemical mechanical polishing of the present invention, as an etchant, fluorine compounds are included as essential components, so as to replace hydrofluoric acid, thereby ensuring the etching property for silicon oxide film, the cerium oxide and fine residual metal ions combined on the surface of semiconductor wafer can be peeled off (lift off) and easily removed. Therefore, if the cleaning liquid composition after chemical mechanical polishing of the present invention (for example, cleaning composition after chemical mechanical polishing) is used, the cleaning effect of pollutants can be maximized without damaging the surface of semiconductor wafer, so that semiconductor devices with improved performance and reliability can be prepared.

[0033] As described above, the chemical mechanical polishing cleaning liquid composition of the present invention has the following advantages during cleaning: to The etching rate of the present invention is about 44% for silicon oxide film and about 93% for silicon nitride film, compared with the conventional cleaning composition using hydrofluoric acid.

[0034] The post-CMP cleaning liquid composition of the present invention can be used to effectively clean polishing residues after a semiconductor wafer including a silicon oxide film and optionally a silicon nitride film or a polysilicon film is subjected to a CMP process.

[0035] In this case, the chemical mechanical polishing process may include a buffing chemical mechanical polishing process, a touch chemical mechanical polishing process, or an isolation chemical mechanical polishing process.

[0036] Specifically, refer to Figure 2 The polishing chemical mechanical polishing process may include all planarization processes performed for the purpose of removing steps or parts of the oxide film after an oxide film for insulation is formed on a conductive pattern such as polysilicon.

[0037] On the other hand, referring to Figure 3The contact chemical mechanical polishing process may include all planarization processes performed to remove contaminants generated on the substrate surface after the chemical mechanical polishing process, the deposition process, or the etching process, for example, a process performed to remove the residues (surface particles) of the polishing process remaining on the surface of the polishing object film, or a process performed to remove embedded particles generated in the deposition process, or a process to remove defects (defect removal) in order to planarize the polished surface that has been ripped out by the etching process, etc. In this case, the polishing object film may be at least one of an oxide film, a nitride film, and a polysilicon film.

[0038] On the other hand, referring to Figure 4 The isolation chemical mechanical polishing process is a process for removing a film excessively deposited or formed on the entire surface of a semiconductor substrate. Specific examples include: (a) an isolation process of polishing an oxide film using a nitride film as a polishing stop film, or (b) an isolation process of polishing an oxide film using polysilicon as a polishing stop film.

[0039] Hereinafter, each component of the post-CMP cleaning liquid composition (eg, post-CMP cleaning composition) of the present invention will be described in more detail.

[0040] (A) Ammonium salt chelating agents

[0041] The post-chemical mechanical polishing cleaning liquid composition of the present invention contains two or more ammonium salt chelating agents.

[0042] The ammonium salt chelating agent can coordinate bond with the cerium oxide particles or fine residual metal particles removed by the etchant to form a complex compound, and the inactivated metal ions are easily dissolved in the cleaning composition and can be easily removed. In addition, the ammonium salt chelating agent acts as a pH buffer under the action of the ammonium salt component and can prevent the pH value of the cleaning liquid composition from changing sharply after chemical mechanical polishing, thereby preventing the re-adsorption of residual abrasive particles and contaminants and effectively improving the generation of surface defects of semiconductor wafers.

[0043] The ammonium salt chelating agent may include an organic acid containing an ammonium salt. As a representative example, it may include at least two selected from the group consisting of ammonium citrate (AC), ammonium oxalate (AMONIUM OXALATE), ammonium carbonate (AMONIUM CARBONATE), ammonium acetate (AMONIUM ACETAMATE), ammonium phosphate (AMONIUM PHOSPHATE, AP), ammonium sulfate (AMONIUM SULFATE), ammonium benzoate (AMONIUM BEZONATE) and ammonium bicarbonate (AMONIUM BICARBONATE). More specifically, the ammonium salt chelating agent may include at least two selected from the group consisting of ammonium citrate, ammonium oxalate, ammonium carbonate, ammonium acetate and ammonium phosphate. Preferably, it may include at least two selected from the group consisting of ammonium citrate, ammonium carbonate, ammonium acetate and ammonium phosphate.

[0044] Based on the total weight of the post-CMP cleaning solution composition, the ammonium salt chelating agent may be included in an amount of 0.5 wt % to 10 wt %, and specifically, the ammonium salt chelating agent may be included in an amount of 2.0 wt % to 9.0 wt %.

[0045] When the ammonium salt chelating agent is included in the above-mentioned range, the chelating component that can react with the metal ions can be fully ensured, so that the cerium oxide particles and other grinding by-products can be effectively removed, and the rapid change of the pH value of the cleaning liquid composition after chemical mechanical polishing can be suppressed to prevent the precipitation of cerium oxide particles and other grinding by-products, thereby effectively improving the generation of surface defects of semiconductor wafers.

[0046] (B) Phosphate chelating agents

[0047] The post-CMP cleaning liquid composition of the present invention may contain one or more phosphoric acid chelating agents.

[0048] Similar to the ammonium salt chelating agent, the phosphoric acid chelating agent can also coordinate and bond with the lifted-off cerium oxide or the remaining metal ions to form a complex, and thus can easily remove the metal ions.

[0049] The phosphate chelating agent is a compound containing a phosphate group or an organic phosphonic acid group as a phosphoric acid organic acid in the molecular structure. As a representative example, it is one or more compounds selected from the group consisting of the following compounds, and specifically, it may contain two or more compounds: ethylidene diphosphonic acid, 1-hydroxyethylidene-1,1'-diphosphonic acid (HEDP), 1-hydroxypropylidene-1,1'-diphosphonic acid, 1-hydroxybutylidene-1,1'-diphosphonic acid, acid), ethylaminobis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, nitrilotris, ethylenediaminebis(methylenephosphonic acid), 1,3-propylenediaminebis(methylenephosphonic acid), ethylene diamine tetra(methylene phosphoric acid) acid, EDTMPA), ethylenediaminetetra (vinyl phosphonic acid), 1,3-propylenediaminetetra (methylene phosphonic acid), 1,2-diaminopropanetetra (methylene phosphonic acid), 1,6-hexamethylenediaminetetra (methylene phosphonic acid), hexanediaminetetra (methylene phosphonic acid), diethylenetriaminepenta (methylene phosphonic acid), diethylenetriaminepentakis (methyl phosphonic acid), N,N,N',N'-ethylenediaminetetra (methylene phosphonic acid),N'-ethylenediaminetetra), diethylenetriaminepenta, triethylenetetraminehex, triethylenetetraminehex, hydrogenphosphate, diammonium hydrogen phosphate, triammoniumhydrogen phosphate, monobutyl phosphate, monoamylphosphate, monononyl phosphate, monocetylphosphate, monophenyl phosphate and monobenzylphosphate.

[0050] Based on the total weight of the post-CMP cleaning solution composition, the phosphate-based chelating agent may be included in an amount of 0.1 wt % to 5 wt %, and specifically, the phosphate-based chelating agent may be included in an amount of 0.1 wt % to 3.0 wt %.

[0051] When the phosphoric acid chelating agent is included in the above range, the chelating component that can react with the metal ions can be fully ensured to effectively remove the cerium oxide particles and other polishing by-products, thereby effectively improving the generation of surface defects. In addition, the rapid change of the pH value of the cleaning liquid composition after chemical mechanical polishing can be suppressed to prevent the precipitation of cerium oxide particles and other polishing by-products, thereby effectively reducing the defects on the surface of the semiconductor wafer.

[0052] (C) Organic acid

[0053] The post-CMP cleaning liquid composition of the present invention may contain one or more organic acids, wherein the organic acid contains one or more and two or less carboxyl groups.

[0054] The organic acid is a substance that contributes to dissolving the oxidized conductive substance in the cleaning solution, and can be used as an oxidized metal dissolving agent.

[0055] When one or more and two or less carboxyl groups (-COOH) in the organic acid are partially adsorbed on the surface of the cerium oxide abrasive grains, the cerium oxide grains are oxidized to increase the solubility of cerium oxide in the cleaning solution, thereby improving the removal efficiency. That is, as shown in the following reaction formula 1, the organic acid included as a dissolving agent dissolves to provide H+ The provided electrons are used in the cerium oxide reduction reaction shown in the following reaction formula 2 to generate reduced Ce(III) ions. Then, the reduced Ce(III) ions are dissolved into Ce(OH) under hydration. 3 , so that it can be easily dissolved in the cleaning composition and removed.

[0056] [Reaction 1]

[0057] R-COOH→R-COO - +H + +e

[0058] [Reaction 2]

[0059] Ce(IV)+e→Ce(III)

[0060] As a representative example, the organic acid may include at least one selected from the group consisting of citric acid (CTA), lactic acid, gluconic acid, maleic acid, malic acid and oxalic acid (OXA), and specifically, may include at least one selected from the group consisting of citric acid, lactic acid, gluconic acid and oxalic acid.

[0061] The post-CMP cleaning solution composition may contain 0.5 wt % to 10 wt % of the organic acid, based on the total weight of the composition. Specifically, the post-CMP cleaning solution composition may contain 0.5 wt % to 8.0 wt % or 0.5 wt % to 5.0 wt % of the organic acid.

[0062] When the organic acid is contained in the above range, H + The supply of ions and electrons "e" is smooth, and the cerium oxide reduction reaction can be easily performed, so that the problem of precipitation of cerium oxide particles due to a decrease in solubility in the cleaning solution can be avoided.

[0063] (D) Fluorine compounds

[0064] The post-CMP cleaning liquid composition of the present invention contains a fluorine compound as an essential component as an etchant in place of hydrofluoric acid.

[0065] The fluorine compound contains fluorine ions and plays a role in etching the surface of the silicon oxide film and lifting off cerium oxide particles or fine residual metal ions bonded to the surface of the semiconductor wafer (see the following reaction formula 3).

[0066] [Reaction 3]

[0067]

[0068] As a representative example, the fluorine compound may include at least one fluorine compound selected from the group consisting of ammonium fluoride (AF), ammonium bifluoride, and tetramethylammonium fluoride (TMAF), and more specifically, may include ammonium fluoride.

[0069] The post-CMP cleaning solution composition may contain 2.0 wt % to 15.0 wt % of the fluorine compound based on the total weight of the composition.

[0070] When the fluorine compound is contained in an amount less than 2.0 wt % as mentioned above, the etching rate of the silicon oxide film decreases sharply due to the lack of fluorine ions, so that the lift-off effect is minimal. In addition, when the fluorine compound is contained in an amount greater than 15.0 wt %, over-etching occurs during the cleaning process due to the increased etching rate of the silicon oxide film, and the surface roughness of the silicon oxide film increases, resulting in an increased incidence of surface defects.

[0071] Preferably, based on the total weight of the post-CMP cleaning solution composition, the fluorine compound may be included in an amount of 2.0 wt % to 10.0 wt %, and specifically, the fluorine compound may be included in an amount of 3.0 wt % to 8.0 wt %.

[0072] (E) Anionic surfactant

[0073] The post-CMP cleaning liquid composition of the present invention may contain an anionic surfactant as a surface modifier.

[0074] The anionic surfactant is adsorbed on the surface of the semiconductor wafer and can modify the surface potential of the semiconductor wafer to negative (Negative), thereby preventing the re-adsorption of the slurry particles after cleaning. For example, in the case where the anti-wear film of the semiconductor wafer is formed by a silicon oxide film or a silicon nitride film, since it has a positive (Positive) potential, metal particles and the like are re-adsorbed and easily contaminated. Therefore, if an anionic surfactant is used to modify the surface of the anti-wear film to a negative (Negative) potential, the Zeta potential (Zeta potential, -mV) value is reduced to a negative value and the adsorption of pollutants can be reduced.

[0075] As a representative example, the anionic surfactant may include at least one selected from the group consisting of polyacrylic acid (PAA) compounds, polyacrylic acid ammonium salt compounds, polyacrylic acid maleic acid, sulfonic acid compounds, sulfonate compounds, sulfonate ester compounds, sulfonate ester salt compounds, acrylic acid / styrene copolymers, polyacrylic acid / styrene copolymers, polyacrylamide / acrylic acid copolymers, polyacrylic acid / sulfonic acid copolymers, and polyacrylic acid / maleic acid copolymers. Specifically, the anionic surfactant may include at least one of polyacrylic acid compounds and sulfonic acid compounds.

[0076] Specifically, the sulfonic acid compound may include at least one selected from the group consisting of alkyl aryl sulfonates, alkyl ether sulfonates, alkyl sulfonates, aryl sulfonates, polystyrene sulfonates, alkane sulfonates, α-olefin sulfonates, dodecylbenzene sulfonates and alkylbenzene sulfonates.

[0077] The post-CMP cleaning solution composition may contain 1.0 wt % to 10 wt % of the anionic surfactant, based on the total weight of the post-CMP cleaning solution composition. Specifically, the post-CMP cleaning solution composition may contain 1.0 wt % to 8.0 wt % of the anionic surfactant.

[0078] When the anionic surfactant is included in the above range, the surface of the wear-resistant film can be easily modified, and the concentration of the cleaning liquid composition after chemical mechanical polishing can be adjusted to prevent the cleaning composition from becoming turbid.

[0079] (F) Water

[0080] The post-CMP cleaning liquid composition of the present invention may contain water as a solvent. The water can control the ease of pH adjustment, handling properties, safety, reactivity with the polished surface, and the like.

[0081] As the water, deionized water, ion exchanged water, ultrapure water or the like may be used. Among them, ultrapure water filtered through an ion exchange resin is preferably used.

[0082] The water may be included as the remainder of the chemical mechanical polishing cleaning liquid composition. Unless otherwise specified, in the chemical mechanical polishing cleaning liquid composition, except for the contents of (A) ammonium salt chelating agent, (B) phosphoric acid chelating agent, (C) organic acid, (D) fluorine compound and (E) anionic surfactant, the remainder is all water.

[0083] On the other hand, the pH of the post-CMP cleaning solution composition of the present invention may be 4 to 7, specifically 5 to 7, and preferably 5 to 6.

[0084] When the pH of the post-CMP cleaning liquid composition of the present invention satisfies the above range, an excellent cleaning effect can be achieved. Specifically, when the pH of the post-CMP cleaning liquid composition is below 4, the Zeta potential rises to a positive value (+mV) and the surface modification of the anti-wear film (e.g., silicon nitride film) cannot be achieved, so that the particles are adsorbed again and the surface defects increase. In addition, when the pH of the post-CMP cleaning liquid composition is above 7, the hydrogen ions (H + ) concentration decreases, and the fluorine compound as an etchant and the reduction reaction of cerium oxide [Ce(IV)+e→Ce(III)] cannot occur, resulting in an increase in surface defects.

[0085] (G) pH adjuster

[0086] The post-CMP cleaning solution composition of the present invention may selectively contain a pH adjuster to maintain the pH range mentioned above.

[0087] The pH adjuster does not relate to the performance of the post-CMP cleaning solution composition, but as a component that can adjust the optimal pH, an alkaline compound containing both a primary amine group and a primary alcohol group can be used. As a representative example, the pH adjuster may include at least one selected from the group consisting of ammonia, ammonium methyl propanol (AMP), monoethanolamine (MEA), triethanolamine, and tromethamine, and specifically, may include monoethanolamine or triethanolamine.

[0088] The pH adjuster may be included in an appropriate amount so that the post-CMP cleaning liquid composition of the present invention can maintain the above pH range and achieve excellent cleaning effect. For example, the post-CMP cleaning liquid composition of the present invention may include the pH adjuster in the range of 0.5 wt % to 10 wt %.

[0089] The chemical mechanical polishing cleaning liquid composition of the present invention as described above is applied after the chemical mechanical polishing process using the cerium oxide slurry composition to effectively remove the cerium oxide and organic matter remaining after the polishing, and the Zeta potential of the substrate surface is reduced to a negative value to prevent the re-adsorption of pollutants, thereby reducing the defects of the polished surface. In addition, the water-based water rinsing performance is also good, and the semiconductor wafer surface can be stably cleaned in a short time, and it has a little silicon oxide film etching function, so the effect of the cleaning method of the chemical action of the cleaning liquid after this polishing process and the physical action of the PVA brush can be maximized. Therefore, the application of the chemical mechanical polishing cleaning liquid composition of the present invention can realize semiconductor devices with improved performance and reliability.

[0090] Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples, but the technical concept of the present invention is not limited thereto.

[0091] (Example)

[0092] (Examples 1 to 10)

[0093] According to the composition shown in Table 1 below, an ammonium salt chelating agent, a phosphoric acid chelating agent, an organic acid, a fluorine compound, and an anionic surfactant (polystyrene sulfonate, weight average molecular weight: 75000 g / mol) were added to water to prepare the chemical mechanical polishing cleaning liquid compositions of Examples 1 to 10. In this case, a pH adjuster (monoethanolamine; MEA) can be added to adjust the pH of the chemical mechanical polishing cleaning liquid compositions of Examples 1 to 10.

[0094] The zeta potential of the prepared post-CMP cleaning liquid composition was measured by electroanalysis using ZEN2600 Zetasizer Nano Z (Malvern), and the results are shown in the following Table 1. In this case, the larger the absolute value of the measured value, the greater the repulsive force between particles, and thus the better the cleaning effect.

[0095] [Table 1]

[0096]

[0097] In the above Table 1, the meanings of the abbreviations are as follows.

[0098] DI:distilled water

[0099] AC:Ammonium Citrate

[0100] AP:Ammonium Phosphate

[0101] EDTMPA: Ethylenediaminetetrakis(methylenephosphonic acid)

[0102] HEDP: 1-Hydroxyethylidene-1,1'-diphosphonic acid

[0103] OXA:Oxalic acid

[0104] CTA: Citric acid

[0105] AF: Ammonium fluoride

[0106] (Comparative Example)

[0107] (Comparative Examples 1 to 7)

[0108] According to the composition of Table 2 below, an ammonium salt chelating agent, a phosphoric acid chelating agent, an organic acid, a fluorine compound, and an anionic surfactant (polystyrene sulfonate, weight average molecular weight: 75000 g / mol) were added to water to prepare the chemical mechanical polishing cleaning liquid compositions of Comparative Examples 1 to 7. In this case, a pH adjuster (monoethanolamine; MEA) can be added to adjust the pH of the chemical mechanical polishing cleaning liquid compositions of Comparative Examples 1 to 7.

[0109] Furthermore, the zeta potential of the prepared post-CMP cleaning solution composition was measured by electroanalysis using a ZEN2600 Zetasizer Nano Z (Malvern). The results are shown in Table 2 below.

[0110] [Table 2]

[0111]

[0112] In the above Table 2, the meanings of the abbreviations are as follows.

[0113] DI: Distilled water

[0114] AC:Ammonium Citrate

[0115] AP:Ammonium Phosphate

[0116] EDTMPA: Ethylenediaminetetrakis(methylenephosphonic acid)

[0117] HEDP: 1-Hydroxyethylidene-1,1'-diphosphonic acid

[0118] OXA:Oxalic acid

[0119] CTA: Citric acid

[0120] AF: Ammonium fluoride

[0121] (Experimental example)

[0122] (Experimental Example 1: Cleaning Ability Evaluation Experiment)

[0123] After the Si wafer on which the multilayer film including the silicon oxide film and the silicon nitride film was deposited was mounted on a chemical mechanical polishing equipment (Elastic NT, KCTECH), a chemical mechanical polishing process was performed at 60 rpm and 1 psi for 30 seconds using a chemical mechanical polishing slurry composition (KCS3100, KCTECH).

[0124] After the chemical mechanical polishing process was completed, the Si wafer that had completed the chemical mechanical polishing process was placed in a cleaning box (PVA brush cleaning box: PVA brush cleaning box) (Brushtek) equipment, and a cleaning process was performed using hydrofluoric acid (HF) in Brush 1 for 7 seconds.

[0125] Then, in Brush 2, an additional cleaning step was performed for 30 seconds using i) the chemical mechanical polishing cleaning liquid composition prepared in the above Examples 1 to 10, ii) the chemical mechanical polishing cleaning liquid composition prepared in Comparative Examples 1 to 7, and iii) a reference example of a commercially available cleaning liquid (SC-1 (Standard Clean-1), ammonia: hydrogen peroxide: water = 1:1:5 weight ratio, APM), and after rinsing with deionized water, nitrogen gas was injected for drying.

[0126] Then, an inspection device (SP2XP (KLA Corporation)) was used to measure whether the residues and contaminants on the surface of the Si wafer were removed. The results are shown in Table 3 below.

[0127] In this case, for the silicon oxide film, residues and contaminants having a diameter of 63 nm or more were evaluated as defects, and for the silicon nitride film, residues and contaminants having a diameter of 52 nm or more were evaluated as defects.

[0128] [Evaluation results]

[0129] ×: When 1,000 or more defects are measured on each film surface

[0130] △: When 500 to 1000 defects are measured on each film surface

[0131] ○: When less than 500 defects were measured on each film surface

[0132] [Table 3]

[0133]

[0134]

[0135] Referring to Table 3 above, it can be seen that compared with the case of using the chemical mechanical polishing post-cleaning liquid composition of the reference example and comparison examples 1 to 7, when using the chemical mechanical polishing post-cleaning liquid composition of embodiments 1 to 10 of the present invention, the defect change rate of the silicon oxide film and the silicon nitride film surface is significantly improved.

[0136] (Experimental Example 2: Silicon Oxide Film Etching Evaluation Experiment)

[0137] An oxide film wafer with an area of ​​2×2 cm was cleaned by spraying distilled water and then dried. The pre-thickness of the oxide film wafer was measured using a reflectometer (Filmmetrics).

[0138] Next, the oxide film wafer was dipped in the post-CMP cleaning liquid compositions of Examples 2 and 7 and the post-CMP cleaning liquid compositions prepared in Comparative Examples 3 and 6 for 60 minutes at room temperature (25±5° C.) or 60° C.

[0139] Then, the oxide film wafer was taken out and washed with distilled water and dried, and then the post thickness was measured.

[0140] The etching rate (Etchrate) was calculated using the following [Formula 1], and the results are shown in the following Tables 4 and Figure 1 .

[0141] [Formula 1]

[0142]

[0143] [Table 4]

[0144]

[0145] Refer to Table 4 and Figure 1 It is known that the etching rate of the oxide film wafer increases in proportion to the content of the fluorine compound contained in the post-CMP cleaning liquid composition.

[0146] Specifically, it can be seen that the chemical mechanical polishing cleaning liquid composition of Example 7, which contains the highest content of fluorine compounds in the chemical mechanical polishing cleaning liquid composition, has the highest etching rate of oxide film wafers. In contrast, in the case of the chemical mechanical polishing cleaning liquid composition of Comparative Example 3, which does not contain fluorine compounds in the chemical mechanical polishing cleaning liquid composition, the oxide film wafer is not etched at all. In the case of the chemical mechanical polishing cleaning liquid composition of Comparative Example 6, which contains 1 weight % of fluorine compounds, the etching property of the oxide film wafer is lower than that of the chemical mechanical polishing cleaning liquid compositions of Examples 2 and 7.

[0147] As can be seen from the above results, the desired etching rate of the silicon oxide film can be controlled by adjusting the content of the fluorine compound contained in the post-CMP cleaning liquid composition.

Claims

1. A post-chemical mechanical polishing cleaning liquid composition, characterized in that: Consists of the following (i) to (vi) or consists of the following (i) to (vii): (i) two or more ammonium salt chelating agents; (ii) phosphate chelating agents; (iii) organic acids containing one or more carboxyl groups; (iv) fluorine compounds; (v) anionic surfactants; (vi) water; and (vii) pH adjusting agent; wherein the ammonium salt chelating agent is at least two selected from the group consisting of ammonium citrate, ammonium oxalate, ammonium carbonate, ammonium acetate and ammonium phosphate, and the post-CMP cleaning solution composition contains 2.0 wt % to 9.0 wt % of the ammonium salt chelating agent based on the total weight of the post-CMP cleaning solution composition; wherein the phosphoric acid chelating agent comprises ethylenediaminetetrakis(methylenephosphonic acid) and 1-hydroxyethylidene-1,1-diphosphonic acid, and the phosphoric acid chelating agent is contained in an amount of 0.1 wt % to 3.0 wt % based on the total weight of the post-chemical mechanical polishing cleaning solution composition; wherein 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, and the organic acid is contained in an amount of 0.5 wt % to 10 wt % based on the total weight of the post-CMP cleaning solution composition; wherein the fluorine compound is at least one selected from the group consisting of ammonium fluoride, ammonium bifluoride and tetramethylammonium fluoride, and the post-CMP cleaning solution composition comprises 2.0 wt % to 10.0 wt % of the fluorine compound based on the total weight of the post-CMP cleaning solution composition; wherein the anionic surfactant is polystyrene sulfonate, and the anionic surfactant is contained in an amount of 1.0 wt % to 10.0 wt % based on the total weight of the post-CMP cleaning solution composition; The pH value of the post-CMP cleaning solution composition is 5 to 7.

2. The post-chemical mechanical polishing cleaning liquid composition according to claim 1, wherein: The pH adjuster includes a compound containing both a primary amine group and a primary alcohol group.

3. The post-chemical mechanical polishing cleaning liquid composition according to claim 1, wherein: The pH adjuster includes at least one selected from the group consisting of ammonia, methylpropanol ammonium, monoethanolamine, triethanolamine, and tromethamine.

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