Polishing composition for semiconductor process, method for preparing polishing composition, and method for manufacturing semiconductor device using polishing composition

Abstract

This invention relates to polishing compositions for semiconductor processes, methods for preparing polishing compositions, and methods for manufacturing semiconductor devices using polishing compositions. Specifically, the polishing compositions of this invention, comprising polishing particles, an accelerator, and a stabilizer, exhibit excellent long-term storage stability without particle aggregation even after prolonged storage at temperatures above 60°C. Furthermore, as polishing compositions applied in polishing processes for amorphous carbon layers, they demonstrate high polishing efficiency, prevent carbon residue generated during the polishing process from adsorbing onto the semiconductor substrate, and prevent contamination of the polishing pad. In addition, this invention also provides a method for manufacturing semiconductor devices using polishing compositions for semiconductor processes.

Description

Technical Field

[0001] This invention relates to polishing compositions for semiconductor processes, methods for preparing polishing compositions, and methods for manufacturing semiconductor devices. Background Technology

[0002] As semiconductor devices become smaller and denser, more sophisticated patterning techniques are being used, leading to more complex surface structures and increased step differences between interlayer films. In the semiconductor device manufacturing process, chemical mechanical polishing (CMP) is used as a planarization technique to remove step differences in specific films formed on a substrate.

[0003] In the CMP process, a slurry is applied to a polishing pad while the substrate is pressurized and rotated to polish its surface. The object to be planarized varies depending on the process step, and the properties of the slurry used also differ accordingly.

[0004] Specifically, CMP technology is not only used for planarization of dielectrics such as silicon oxide (SiO2) and silicon nitride (SiN), but it is also essential for planarization of metal wiring such as tungsten (W) and copper (Cu).

[0005] With the increasing integration of semiconductor devices, there is a need to form more intricate patterns and multi-layered circuit structures.

[0006] Therefore, films made of various materials with different etch selectivity are needed. Among these films made of various materials, carbon-based organic films have good etch selectivity characteristics compared to other silicon-containing films and can be used as mask films or sacrificial films.

[0007] In semiconductor manufacturing processes, organic films need to be removed using chemical mechanical polishing (CMP). However, a polishing composition has not yet been developed that can effectively polish organic films used in semiconductor manufacturing processes by applying CMP.

[0008] Therefore, there is a need to develop polishing compositions for semiconductor processes that can solve the above problems. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The purpose of this invention is to provide a polishing composition for semiconductor processes, a method for preparing the polishing composition, and a method for manufacturing semiconductor devices using the polishing composition.

[0011] Another object of the present invention is to provide a polishing composition for semiconductor processes, wherein the polishing rate does not decrease when the polishing composition is used for polishing at a temperature above 60°C, and no agglomeration occurs between particles after long-term storage, thus exhibiting excellent long-term storage stability.

[0012] Another object of the present invention is to provide a polishing composition for semiconductor processes, wherein the polishing composition can be applied to the polishing process of amorphous carbon layers, exhibiting a high polishing rate for amorphous carbon layers as the target thin film, preventing carbon residue generated during the polishing process from adsorbing onto the semiconductor substrate, and preventing contamination of the polishing pad.

[0013] Another object of the present invention is to provide a method for manufacturing a semiconductor device using a polishing composition suitable for semiconductor processes.

[0014] means for solving problems

[0015] To achieve the above objectives, a polishing composition for semiconductor processes according to an embodiment of the present invention comprises polishing particles, an accelerator, and a stabilizer, and the aggregation index (CI) represented by Formula 1 is 0.5 to 5:

[0016] [Formula 1]

[0017]

[0018] Wherein, Sai is the average particle size of the polishing particles contained in the polishing composition for semiconductor processing, measured by a dynamic light scattering particle size analyzer, while Saf is the average particle size of the polishing particles contained in the polishing composition after the polishing composition for semiconductor processing has been held at 60°C for 17 hours and then cooled at 15°C to 25°C, measured by a dynamic light scattering particle size analyzer.

[0019] A method for preparing a polishing composition for semiconductor processes according to another embodiment of the present invention may include the following steps: step a), adding a stabilizer and an accelerator to a solvent and mixing them to prepare a polishing solution; step b), adding a pH adjuster to the polishing solution to adjust the pH value of the polishing solution to 2 to 5; and step c), mixing a surfactant and polishing particles in the polishing solution with a pH value of 2 to 5.

[0020] A method for manufacturing a semiconductor device according to another embodiment of the present invention may include the following steps: step 1), providing a polishing pad including a polishing layer; step 2), providing a polishing composition for semiconductor processing to the polishing pad; and step 3), rotating the polished object relative to the polishing surface in such a way that the polished surface of the polishing object contacts the polishing surface of the polishing layer, thereby polishing the polishing object.

[0021] Invention Effects

[0022] With respect to the present invention, the polishing composition of the present invention does not decrease the polishing rate when polishing is performed at a temperature above 60°C; and no agglomeration occurs between particles after long-term storage, thus exhibiting excellent long-term storage stability; furthermore, it can exhibit a high polishing rate in the polishing process of amorphous carbon layer, and can also prevent carbon residue generated in the polishing process from adsorbing onto the semiconductor substrate and prevent contamination of the polishing pad.

[0023] In addition, a method for manufacturing a semiconductor device using the polishing composition for semiconductor processing can be provided. Attached Figure Description

[0024] Figure 1 This is a schematic process diagram of a semiconductor device manufacturing process according to an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures

[0026] 110: Polishing pad

[0027] 120: Tablet

[0028] 130: Semiconductor substrate

[0029] 140: Nozzle

[0030] 150: Polishing slurry

[0031] 160: Polishing head

[0032] 170: Dresser Detailed Implementation

[0033] The embodiments of the present invention are described in detail below to enable those skilled in the art to implement the invention. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0034] The embodiments of the present invention are described in detail below to enable those skilled in the art to implement the invention. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0035] In this specification, unless otherwise stated, "includes" another component means that it may also include other components, rather than excluding other components.

[0036] In this specification, when a structure is referred to as being "connected" to another constituent element, this includes not only the case of "direct connection" but also the case of "connection with other constituent elements in between".

[0037] In this specification, "B is located on A" means that B is located on A in direct contact with A or in the presence of other layers in between. It should not be interpreted as simply B being located on the surface of A in contact with A.

[0038] In this specification, the term "mixture of them" included in the Markush type description refers to a mixture or combination of one or more of the constituent elements selected from the group consisting of the multiple constituent elements of the Markush type description, thereby indicating that it includes one or more of the constituent elements selected from the group consisting of the multiple constituent elements mentioned above.

[0039] In this specification, the reference to "A and / or B" means "A, B, or A and B".

[0040] In this specification, unless otherwise stated, terms such as “first,” “second,” or “A,” “B,” etc., are used to distinguish the same terms from each other.

[0041] In this specification, unless otherwise stated, the use of the singular can be interpreted to include the meaning of either the singular or the plural as may be understood from the context.

[0042] The present invention will now be described in more detail.

[0043] As semiconductor devices become smaller and denser, their surface structures become more complex. This increased complexity means that the linewidth of the semiconductor becomes narrower, and the aspect ratio (the ratio of the horizontal to the vertical dimension) gradually increases. To accommodate the ever-increasing aspect ratio, the photoresist also becomes thinner.

[0044] However, the thinned and elongated photoresist cannot withstand the etching process and will tilt. To prevent this phenomenon, a hard mask process was introduced.

[0045] Amorphous carbon and SiON were used as the hard mask materials.

[0046] Although the amorphous carbon exhibits excellent etch resistance when used as a hard mask, when applied to a chemical mechanical polishing process using conventional polishing compositions, the polishing rate is low and carbon residue is generated. This carbon residue adsorbs onto the thin film surface, leading to defects in the semiconductor substrate.

[0047] Therefore, the polishing composition for semiconductor processes of the present invention not only exhibits a high polishing rate for amorphous carbon films, but also prevents the reabsorption of carbon residues and prevents defects in the semiconductor substrate.

[0048] Specifically, the polishing composition for semiconductor processes of the present invention comprises polishing particles, an accelerator and a stabilizer, and has an aggregation index (CI) of 0.5 to 5 as expressed by Formula 1 below.

[0049] [Formula 1]

[0050]

[0051] Wherein, Sai is the average particle size of the polishing particles contained in the polishing composition for semiconductor processing, measured by a dynamic light scattering particle size analyzer, while Saf is the average particle size of the polishing particles contained in the polishing composition after the polishing composition for semiconductor processing has been held at 60°C for 17 hours and then cooled at 15°C to 25°C, measured by a dynamic light scattering particle size analyzer.

[0052] The polishing composition of the present invention does not reduce the polishing rate even when the polishing process is performed at temperatures above 60°C. Furthermore, since no agglomeration or oxidation occurs between the polishing particles, particle size increase can be prevented.

[0053] Specifically, regarding the polishing composition, the average diameter of the particles may increase due to particle aggregation during prolonged storage. As mentioned above, with the increase in the average particle diameter, a decrease in polishing rate may occur when used in the polishing process. Furthermore, this also means that when the polishing composition is added to a polishing process at temperatures above 60°C, agglomeration of the polishing particles in the polishing composition may occur.

[0054] In contrast, the polishing composition of the present invention can prevent the agglomeration of polishing particles even during long-term storage, thereby preventing the problem of increased polishing particle size. Specifically, as described above, by preventing the agglomeration of polishing particles, the reduction in polishing rate can be prevented, and storage stability can also be greatly improved.

[0055] Formula 1 relates to the storage stability of the polishing composition of the present invention and its stability when polishing at temperatures above 60°C. According to Formula 1, if the initial average diameter (nm) of the polishing particles and the average diameter (nm) of the polishing particles measured after holding at 60°C for 17 hours and then cooling at 15°C to 25°C are 0.5 to 5, it means that the average diameter of the particles does not change significantly.

[0056] As mentioned above, this means that even with long-term storage, the average diameter of the particles will not change, thus exhibiting excellent storage stability and preventing the problem of reduced polishing rate due to long-term storage.

[0057] Dynamic light scattering (DLS) is a non-invasive technique for measuring the size of nanoparticles in a dispersion system. DLS utilizes Brownian motion to measure the intensity of scattered light over time in a particle suspension. By analyzing the intensity change of the scattered light, a diffusion coefficient that reveals the particle size can be determined, and the particle size can be calculated from this coefficient using the Stoke-Einstein equation.

[0058] Using the average particle diameter measured by the dynamic light scattering method as the initial state and the average particle size of the polishing particles in the polishing composition after the agglomeration acceleration process, the value calculated based on the agglomeration index (CI) of Formula 1 can be 0.5 to 5, 0.5 to 1.50, 0.5 to 1.40, 0.5 to 1.30, 0.5 to 1.25, 0.7 to 1.22, 0.7 to 1.15, or 0.7 to 1.12. When the agglomeration index meets the above range, even during long-term storage at temperatures above 60°C, the problem of polishing particle size increase can be prevented, thereby preventing a decrease in polishing rate and greatly improving storage stability. Furthermore, even when used in polishing processes at temperatures above 60°C, the problem of a decrease in polishing rate does not occur.

[0059] In another embodiment of the invention, based on the following formula 2, the average diameter increase rate of the polishing particles in the polishing composition can be from 0.5% to 30%:

[0060] [Equation 2]

[0061]

[0062] Wherein, Sai is the average particle size of the polishing particles contained in the polishing composition for semiconductor processing, measured by a dynamic light scattering particle size analyzer, while Saf is the average particle size of the polishing particles contained in the polishing composition after the polishing composition for semiconductor processing has been held at 60°C for 17 hours and then cooled at 15°C to 25°C, measured by a dynamic light scattering particle size analyzer.

[0063] The values ​​of Equation 2 can be 0.5% to 30%, 0.5% to 25%, 0.5% to 20%, 0.5% to 15%, 0.5% to 10%, or 0.5% to 7%. When these ranges are met, even during long-term storage at temperatures above 60°C, the problem of polishing particle size increase can be prevented, thereby preventing a decrease in the polishing rate and significantly improving storage stability. Furthermore, even when used in polishing processes at temperatures above 60°C, a decrease in the polishing rate does not occur, and the occurrence of defects can be prevented.

[0064] In particular, the polishing composition of the present invention can be used in the polishing process of amorphous carbon films (ACLs), and the polishing rate for amorphous carbon films can be from 100 Å / min to 250 Å / min, 110 Å / min to 200 Å / min, or 120 Å / min to 200 Å / min. In other words, when polishing amorphous carbon films using the polishing composition, the polishing efficiency is excellent when the polishing rate is within the aforementioned range, thus enabling its use in the polishing process of amorphous carbon films.

[0065] Traditional polishing compositions have the problem of being difficult to apply to polishing processes due to their low polishing rate for amorphous carbon films.

[0066] To address the aforementioned issues, progress has been made in the development of technologies that improve the polishing rate of amorphous carbon films by incorporating additives into polishing compositions. However, even with improved polishing rates, conventional polishing compositions still present the following problems: the polishing rate decreases when the polishing process is carried out at high temperatures, or the polishing particles agglomerate during long-term storage, resulting in decreased storage stability.

[0067] In addition, there are problems such as carbon residue generated during the polishing process adsorbing onto the surface of the semiconductor substrate and causing contamination of the polishing pad.

[0068] In the case of the polishing composition of the present invention, when used in the polishing process of amorphous carbon films, it not only exhibits a polishing rate of 100 Å / min to 250 Å / min, thereby enabling it to be used in the polishing process at a high polishing rate, but also does not experience a decrease in polishing rate even under conditions above 60°C, and does not experience a decrease in polishing rate even after long-term storage.

[0069] Furthermore, it can prevent carbon residues generated during the polishing process from adsorbing onto the surface of the semiconductor substrate and prevent polishing pad contamination.

[0070] Specifically, the polishing particles are selected from the group consisting of metal oxides, organic particles, organic-inorganic composite particles, and mixtures thereof.

[0071] The polishing particles, as polishing particles applicable to polishing compositions for semiconductor processes, are selected, for example, from the group consisting of metal oxides, organic particles, organic-inorganic mixed particles, and mixtures thereof. The metal oxides may be selected from the group consisting of colloidal silica, fumed silica, cerium dioxide, alumina, titanium dioxide, zirconium oxide, zeolite, and mixtures thereof, but are not limited to the examples described. Any metal oxide particles selectable by those skilled in the art can be used without restriction.

[0072] The organic particles may be polystyrene, styrene-based copolymers, poly(meth)acrylate, (meth)acrylate-based copolymers, polyvinyl chloride, polyamide, polycarbonate, and polyimide polymers; or the polymers may form particles with a core, shell, or a core / shell structure of both, and they may be used alone or in combination, and the organic particles may be prepared by emulsion polymerization, suspension polymerization, etc.

[0073] Specifically, the polishing particles of the present invention can be selected from the group consisting of colloidal silica, fumed silica, cerium dioxide, and mixtures thereof.

[0074] The average diameter of the polishing particles can be 10nm to 120nm, 20nm to 100nm, 40nm to 80nm, 45nm to 70nm, or 70nm to 80nm. When the metal oxide particles fall within the scope of this invention, defects such as scratches on the semiconductor substrate can be prevented during the polishing process, and the dispersion of the polishing particles is excellent.

[0075] The accelerator can be selected from the group consisting of anionic small molecules, anionic polymers, hydroxy acids, amino acids, and cerium salts. Specifically, the cerium salt can be a trivalent or tetravalent cerium salt. More specifically, the tetravalent cerium salt can be selected from the group consisting of cerium(IV) sulfate (Ce(SO4)2), cerium ammonium sulfate dihydrate, and cerium ammonium nitrate, but is not limited to the examples described.

[0076] The accelerator is included in the polishing composition, which makes it easier to remove the surface layer of the amorphous carbon film by oxidizing the surface layer of the amorphous carbon film into oxides or ions.

[0077] In addition, it has the following advantages: it makes it easier to remove the residue of organic film material present in the polishing stop film layer, thereby making the polishing more uniform.

[0078] The cerium ammonium nitrate can exist in the slurry composition in the form of an ionic compound or a chelate, and when used in the form of said compound, it can provide a high polishing speed for amorphous carbon films.

[0079] However, when only accelerators are included to increase the polishing rate of amorphous carbon films, the stability of the polishing composition may decrease, making it difficult to store for long periods of time, and surface defects on the semiconductor substrate may occur during the polishing process.

[0080] Therefore, in the case of the present invention, the combined use of accelerator and stabilizer not only exhibits the effect of increasing the polishing rate of amorphous carbon films based on the accelerator, but also improves the stability of the polishing composition based on the stabilizer, and can prevent the occurrence of defects in the polishing process.

[0081] Specifically, the stabilizer is an amino acid, and more specifically, the amino acid can be selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, glutamine, cysteine, proline, asparagine, threonine, alanine, glycine, valine, leucine, isoleucine, and mixtures thereof, preferably alanine, but not limited to the examples described. Any amino acid that can improve the stability of the polishing composition by being used in combination with an accelerator and can suppress the occurrence of defects in the polishing process can be used without restriction.

[0082] The polishing composition of the present invention, as a composition additionally containing a surfactant, exhibits a high polishing rate for amorphous carbon films and prevents carbon residues from re-adsorbing onto the semiconductor substrate based on the reduction of surface tension.

[0083] When an accelerator is included in the polishing composition to increase the polishing rate of the amorphous carbon film, the polishing rate is increased, but the following problems arise: carbon residue generated during the polishing process adsorbs onto the semiconductor substrate and the polishing pad becomes contaminated.

[0084] To address the aforementioned issues, a surfactant is incorporated into the polishing composition to reduce its surface tension. This reduction in surface tension prevents carbon residues from re-adsorbing onto the substrate surface and also prevents contamination of the polishing pad.

[0085] Specifically, the surfactant may include a nonionic fluorinated polymer. The surfactant, including the fluorinated polymer, can prevent carbon residues from re-adsorbing onto the surface of the semiconductor substrate when used in the polishing process of amorphous carbon films.

[0086] Furthermore, because the surfactant contains fluorine, it can inhibit the growth of microorganisms such as bacteria and mold. When the polishing composition is stored for a long time, bacteria and mold may grow, and the polishing composition with such bacteria and mold cannot be used in the polishing process and must be discarded.

[0087] In the polishing composition of the present invention, the surfactant includes a nonionic fluorinated polymer compound, which prevents the growth of bacteria and mold when the polishing composition is stored for a long time, thereby improving long-term storage stability.

[0088] The surfactant of this invention can be specifically selected from Chemours. tm The group consisting of FS-30, FS-31, FS-34, ET-3015, ET-3150, ET-3050 and mixtures thereof from the company, but is not particularly limited as long as it is a substance that can prevent carbon residues from being re-adsorbed onto the surface of the semiconductor substrate.

[0089] The surfactant described in this invention is a nonionic surfactant, which can be used alone, including nonionic fluorinated polymers, or in combination with other nonionic surfactants.

[0090] The nonionic surfactant can be selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene-propylene copolymer, polyalkyl oxide, polyethylene oxide (PEO), polyethylene oxide, and polypropylene oxide. The fluorosurfactant can be selected from the group consisting of sodium sulfonate fluorosurfactant, phosphate ester fluorosurfactant, amine oxide fluorosurfactant, betaine fluorosurfactant, ammonium carboxylate fluorosurfactant, stearate ester fluorosurfactant, quaternary ammonium fluorosurfactant, and ethylene oxide / propylene oxide fluorosurfactant. The group consists of fluorosurfactant and polyoxyethylene fluorosurfactant.

[0091] The polishing composition of the present invention may include a pH adjuster, said pH adjuster being selected from at least one of the following groups: hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, nitric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, citric acid, acetic acid, propionic acid, fumaric acid, oleic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, and potassium hydroxide.

[0092] The pH adjuster can adjust the pH value of the polishing composition for semiconductor processes to 2 to 5, or preferably 2 to 4. Maintaining an acidic environment within this range allows for the preservation of polishing speed and quality while preventing excessive corrosion of the metal components or polishing equipment.

[0093] The polishing composition for semiconductor processes may comprise 0.1% to 0.5% by weight polishing particles, 1% to 2% by weight accelerator, 1% to 2% by weight stabilizer, 0.001% to 0.01% by weight surfactant, and the remainder being a solvent. When the content of the polishing composition is within the above range, the accelerator becomes stable due to the stabilizer, thereby increasing the accelerator-based polishing rate in the polishing composition, and the stabilizer and surfactant prevent the occurrence of defects in the polishing process.

[0094] The solvent is ultrapure water, but is not limited to the example above; any solvent that can be used as a solvent for the polishing composition can be used without restriction.

[0095] When the content of the surfactant is less than the above-mentioned range, the defects occurring on the surface of the semiconductor substrate increase during the polishing process, and when the content of the surfactant is greater than the above-mentioned range, a large number of bubbles are generated during the preparation of the polishing composition.

[0096] The method for preparing the polishing composition according to the present invention may include the following steps: step a), adding and mixing a stabilizer and an accelerator in a solvent to prepare a polishing solution; step b), adding a pH adjuster to the polishing solution to adjust the pH value of the polishing solution to 2 to 5; and step c), mixing a surfactant and polishing particles in the polishing solution with a pH value of 2 to 5.

[0097] In step a), in order to stabilize the accelerator, the stabilizer can be mixed in the solvent to prepare the first solvent, and then the accelerator can be mixed in to prepare the polishing solution.

[0098] Regarding the accelerator, when it is prepared by mixing ultrapure water as a solvent with other stabilizers, pH adjusters, surfactants and polishing particles, the accelerator is unstable in the polishing composition, making it difficult to store for a long time when preparing the polishing composition, or it may not show the effect of increasing the polishing rate based on the accelerator in the polishing composition.

[0099] To prevent this problem, after mixing a stabilizer in a solvent to prepare a first solution, an accelerator is dissolved in the first solution to prepare a polishing solution, and then a polishing composition is prepared through subsequent steps.

[0100] A method for manufacturing a semiconductor device according to another embodiment of the present invention may include the following steps: step 1), providing a polishing pad including a polishing layer; step 2), providing a polishing composition for semiconductor processing to the polishing pad; step 3), polishing the object by rotating it relative to the polished surface of the polishing object in such a way that the polished surface is in contact with the polishing surface of the polishing layer. Furthermore, the polishing composition comprises polishing particles, an accelerator, and a stabilizer, and has an aggregation index of 0.5 to 5, as expressed by Formula 1:

[0101] [Formula 1]

[0102]

[0103] Wherein, Sai is the average particle size of the polishing particles contained in the polishing composition for semiconductor processing, measured by a dynamic light scattering particle size analyzer, while Saf is the average particle size of the polishing particles contained in the polishing composition after the polishing composition for semiconductor processing has been held at 60°C for 17 hours and then cooled at 15°C to 25°C, measured by a dynamic light scattering particle size analyzer.

[0104] Figure 1 This is a schematic process diagram illustrating a semiconductor device manufacturing process according to an embodiment of the present invention. (Refer to...) Figure 1 After mounting a polishing pad 110 according to one embodiment on a flat plate 120, a semiconductor substrate 130, which is to be polished, is arranged on the polishing pad 110. For polishing, polishing slurry 150 is sprayed onto the polishing pad 110 through a nozzle 140.

[0105] The flow rate of the polishing slurry 150 supplied through the nozzle 140 can be approximately 10 cm. 3 / min to approximately 1000cm 3 The range of / min should be selected based on the purpose; for example, it could be approximately 50cm. 3 / min to approximately 500cm 3 / min, but not limited to this.

[0106] The polished surface of the semiconductor substrate 130 is in direct contact with the polished surface of the polishing pad 110.

[0107] Subsequently, the semiconductor substrate 130 and the polishing pad 110 rotate relative to each other, thereby enabling the surface of the semiconductor substrate 130 to be polished. At this time, the rotation direction of the semiconductor substrate 130 and the rotation direction of the polishing pad 110 can be the same or opposite. The rotation speed of the semiconductor substrate 130 and the polishing pad 110 can be selected from approximately 10 rpm to approximately 500 rpm depending on the purpose, for example, from approximately 30 rpm to approximately 200 rpm, but is not limited thereto.

[0108] As an example of the polishing process for the substrate, the organic film of the substrate is polished, which can be applied to the polishing process of carbon-based organic films.

[0109] Specifically, examples of carbon-based organic films include C-SOH (spin-on hard mask) films, amorphous carbon films, or NCP films, with amorphous carbon films being preferred as they exhibit excellent selective polishing effects and can demonstrate high polishing rates.

[0110] The specific description of the polishing composition for semiconductor processes is repeated above, so it is omitted here.

[0111] In one embodiment, in order to keep the polishing surface of the polishing pad 110 in a state suitable for polishing, the method for fabricating the semiconductor device may further include the following steps: that is, while polishing the semiconductor substrate 130, the polishing surface of the polishing pad 110 is processed by a dressing device 170.

[0112] Preparation of compositions for semiconductor polishing

[0113] Example 1

[0114] A polishing solution was prepared by mixing alanine as a stabilizer in ultrapure water to form a mixed solution, followed by mixing cerium ammonium nitrate.

[0115] Nitric acid was mixed into the polishing solution to adjust the pH to 2.1, and then Chemours was added. tm A polishing composition was prepared by using the surfactant FS-30 from the company and colloidal silica with a diameter of 75 nm.

[0116] The content of the components in Examples 1 to 5, Comparative Example 1 and Comparative Example 2 is shown in Table 1 below.

[0117] [Table 1]

[0118]

[0119] (Unit: % by weight)

[0120] Experimental Example 1

[0121] Determination of polishing rate based on changes in polishing particle size

[0122] Polishing rates were measured for Example 1, Comparative Example 1, and Comparative Example 2, thereby determining the polishing rate of the ACL film as a function of the size variation of the polishing particles.

[0123] A 2000 Å thick amorphous carbon layer (ACL) was polished for 60 seconds under polishing conditions of 2 psi, carrier speed of 87 rpm, platen speed of 93 rpm, and inflow rate of polishing composition of 200 ml / min, and the polishing rate was measured.

[0124] [Table 2]

[0125]

[0126]

[0127] Table 2 above shows the comparison results of polishing rates based on the average diameter of the polishing particles contained in the polishing composition. In the case of Example 1, a polishing rate of 141 Å / min, or more than 120 Å / min, was observed. In contrast, in Comparative Example 1, the average diameter of the polishing particles was 45 nm, and the polishing rate was 63 Å / min, while in Comparative Example 2, the average diameter of the polishing particles was 60 nm, and the polishing rate was 103 Å / min, thus confirming a lower polishing rate for amorphous carbon films. Based on the above experimental results, it is confirmed that when the size of the polishing particles is small, the polishing rate for amorphous carbon films is lower.

[0128] Experiment Example 2

[0129] Polishing rate based on polishing particle content range and surface defect measurement results

[0130] For a polishing composition containing colloidal silica with a particle size of 75 nm and colloidal silica with a particle size of 45 nm, the contents were configured to have different contents, and the size changes were measured according to polishing rate, number of defects and temperature.

[0131] The polishing rate was measured under the same polishing conditions as in Experiment 1, and the presence or absence of defects was confirmed using KLA Tencor AIT-XP+.

[0132] To determine whether the particle size had increased, the initial average diameter of the particles and the average diameter of the heated particles were measured using a dynamic light scattering particle size analyzer.

[0133] For the heating conditions used in the measurement, the polishing composition was kept in an oven preheated to 60°C for 17 hours, then cooled to 20°C, and the average diameter was measured.

[0134] For dynamic light scattering particle size analysis, a dynamic light scattering particle size analyzer was used, specifically the Malvern Nano-ZS, with colloidal silica as the input material and a refractive index of 1.457 as the input.

[0135] The average diameter of the particles was measured by injecting 2 ml of each of the polishing compositions of the examples and comparative examples into the dynamic light scattering particle size analyzer.

[0136] For the measured average diameter of the particles, the value was confirmed according to Equation 1 below, and the diameter increase rate of the polished particles was calculated based on Equation 2 below:

[0137] [Formula 1]

[0138]

[0139] [Equation 2]

[0140]

[0141] Wherein, Sai is the average particle size of the polishing particles contained in the polishing composition for semiconductor processing, measured by a dynamic light scattering particle size analyzer, while Saf is the average particle size of the polishing particles contained in the polishing composition after the polishing composition for semiconductor processing has been held at 60°C for 17 hours and then cooled at 15°C to 25°C, measured by a dynamic light scattering particle size analyzer.

[0142] [Table 3]

[0143]

[0144] According to Table 3 above, in Examples 1 to 5, the value of Equation 1 was confirmed to be approximately 1, thus confirming that even after the polishing composition was kept in an oven preheated to 60°C for 17 hours and then cooled at 20°C, the average diameter of the particles did not show a significant change. Analysis of other examples showed that when the particle diameter was 45 nm, the polishing rate increased with increasing content, but when the polishing composition was kept in an oven preheated to 60°C for 17 hours and then cooled at 20°C, the size of the polishing particles increased; when the particle diameter was 75 nm, the polishing rate did not show a significant difference with increasing content, and it was also confirmed that the increase in particle size after heating was more significant when the particle diameter was 75 nm compared to when the particle diameter was 45 nm. In contrast, Comparative Example 3, a polishing composition with an average polishing particle diameter of 45 nm and a content of 2.5% by weight, showed a very large increase in the number of polishing particles after heating, and it was confirmed that a large number of defects occurred as a result.

[0145] The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art using the basic concepts of the present invention as defined in the claims are all within the scope of the present invention.

[0146] Industrial applicability

[0147] This invention relates to polishing compositions for semiconductor processes, methods for preparing polishing compositions, and methods for manufacturing semiconductor devices using polishing compositions.

Claims

1. A polishing composition for semiconductor process, wherein, the polishing composition comprises: a polishing particle; an accelerator; and a stabilizer, the polishing particle has an average diameter of 70 nm to 120 nm, a polishing rate for an amorphous carbon film having a thickness of 2000 angstroms is 110 angstroms / minute to 250 angstroms / minute when a polishing process is performed for 60 seconds under a polishing condition of 2 psi, a carrier speed of 87 rpm, a table speed of 93 rpm, and an inflow flow rate of the polishing composition of 200 ml / min, and an aggregation index represented by the following Formula 1 is 0.5 to 5: [Formula 1] , wherein, the Sai is an average particle diameter of the polishing particle contained in the polishing composition for semiconductor process measured by a dynamic light scattering particle size analyzer, the Saf is an average particle diameter of the polishing particle contained in the polishing composition measured by the dynamic light scattering particle size analyzer after the polishing composition for semiconductor process is maintained at 60℃ for 17 hours and then cooled at 15℃ to 25℃. 2.The polishing composition for semiconductor process according to claim 1, wherein, the polishing particle is selected from the group consisting of a metal oxide, an organic particle, an organic-inorganic composite particle, and a mixture thereof. 3.The polishing composition for semiconductor process according to claim 1, wherein, the accelerator is selected from the group consisting of an anionic small molecule, an anionic polymer, a hydroxy acid, an amino acid, and a cerium salt. 4.The polishing composition for semiconductor process according to claim 1, wherein, the stabilizer is an amino acid. 5.The polishing composition for semiconductor process according to claim 1, wherein, the polishing composition comprises a surfactant. 6.The polishing composition for semiconductor process according to claim 1, wherein, the polishing composition comprises a pH adjuster. 7.The polishing composition for semiconductor process according to claim 1, wherein, for the polishing particle, an average diameter increase rate of the particle based on the following Formula 2 is 0.5% to 30%: [Formula 2] wherein, the Sai is an average particle diameter of the polishing particle contained in the polishing composition for semiconductor process measured by a dynamic light scattering particle size analyzer, the Saf is an average particle diameter of the polishing particle contained in the polishing composition measured by the dynamic light scattering particle size analyzer after the polishing composition for semiconductor process is maintained at 60℃ for 17 hours and then cooled at 15℃ to 25℃.

8. A method for producing a semiconductor process composition, wherein, comprises the following steps: step a), adding and mixing a stabilizer and an accelerator in a solvent to thereby prepare a polishing solution; step b), adding a pH adjuster to the polishing solution to thereby adjust a pH value of the polishing solution to 2 to 5; and step c), mixing a surfactant and a polishing particle in the polishing solution having the pH value of 2 to 5, the polishing particle has an average diameter of 70 nm to 120 nm, polishing the amorphous carbon film having a thickness of 2,000 angstroms for 60 seconds using the polishing composition under polishing conditions of 2 psi, a carrier speed of 87 rpm, a table speed of 93 rpm, and an inflow rate of the polishing composition of 200 ml / min, a polishing rate of the amorphous carbon film of 110 to 250 angstroms / min is measured, wherein the aggregation index represented by the following Formula 1 of the polishing composition is 0.5 to 5: [Formula 1] , the Sai is an average particle diameter of polishing particles contained in the polishing composition for semiconductor processes, which is measured by a dynamic light scattering particle size analyzer, the Saf is an average particle diameter of polishing particles contained in the polishing composition for semiconductor processes, which is measured by a dynamic light scattering particle size analyzer after the polishing composition for semiconductor processes is maintained at 60°C for 17 hours and then cooled at 15 to 25°C.

9. The method for producing a semiconductor process composition according to claim 8, wherein the step a) is: mixing the stabilizer in a solvent to prepare a mixed solution, and then mixing the accelerator in the mixed solution to prepare a polishing solution.

10. A method of manufacturing a semiconductor device, wherein, comprises the following steps: Step 1) providing a polishing pad including a polishing layer; Step 2) providing the polishing pad with a polishing composition for semiconductor processes; and Step 3) relatively rotating the polishing object in a manner that a polishing surface of the polishing object is in contact with a polishing surface of the polishing layer, thereby polishing the polishing object, the polishing composition contains polishing particles, an accelerator, and a stabilizer, an average diameter of the polishing particles is 70 to 120 nm, polishing the amorphous carbon film having a thickness of 2,000 angstroms for 60 seconds using the polishing composition under polishing conditions of 2 psi, a carrier speed of 87 rpm, a table speed of 93 rpm, and an inflow rate of the polishing composition of 200 ml / min, a polishing rate of the amorphous carbon film of 110 to 250 angstroms / min is measured, for the polishing composition, the aggregation index represented by the following Formula 1 is 0.5 to 5: [Formula 1] , wherein the Sai is an average particle diameter of polishing particles contained in the polishing composition for semiconductor processes, which is measured by a dynamic light scattering particle size analyzer, the Saf is an average particle diameter of polishing particles contained in the polishing composition for semiconductor processes, which is measured by a dynamic light scattering particle size analyzer after the polishing composition for semiconductor processes is maintained at 60°C for 17 hours and then cooled at 15 to 25°C.

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