Polishing composition for semiconductor process, method for preparing the polishing composition, and method for preparing a semiconductor element using the polishing composition

Abstract

The present invention relates to a polishing composition for semiconductor process and a method for producing a semiconductor element using the polishing composition, and can provide a production method that is applied to a CMP process of an amorphous carbon film, exhibits a high polishing rate, prevents carbon residues in the CMP process from being re-adsorbed onto a semiconductor substrate, prevents contamination of a polishing pad, and stabilizes an accelerator in the polishing composition to achieve excellent storage stability. In addition, a method for producing a semiconductor element using the polishing composition for semiconductor process can be provided.

Description

Technical Field

[0001] The present invention relates to a polishing composition for semiconductor process, a method for preparing the polishing composition, and a method for preparing a semiconductor element using the polishing composition. Background Art

[0002] As semiconductor elements become more miniaturized and denser, more sophisticated patterning techniques are being used. Accordingly, the surface structure of semiconductor elements has become more complex, and the step difference of the interlayer film has become larger. When manufacturing semiconductor elements, a chemical mechanical polishing (CMP) process is used as a flattening technique for removing the step difference generated in a specific film formed on a substrate.

[0003] In the CMP process, slurry is supplied to the polishing pad, and the surface is polished while the substrate is pressed and rotated. The object to be flattened varies depending on the process step, and the physical properties of the slurry used at this time also vary.

[0004] Specifically, the CMP process is not only applicable to the planarization of dielectrics such as silicon oxide films (SiO2) and silicon nitride films (SiN), but is also essential in the planarization process of metal wiring such as tungsten (W) and copper (Cu).

[0005] As semiconductor devices become more highly integrated, it is necessary to form circuits with finer patterns and multilayer structures.

[0006] For this purpose, films of various materials having different etching selectivity characteristics are required. Among these films of various materials, carbon-based organic films have good etching selectivity characteristics relative to other silicon-containing films, and thus can be used as masks or sacrificial films.

[0007] In the semiconductor manufacturing process, it is required to remove the organic film by chemical mechanical polishing process. However, for the organic film used in the semiconductor manufacturing process, there is no polishing composition that can be effectively polished by CMP process.

[0008] There is a need to develop a polishing composition for semiconductor processing that can solve the above-mentioned problems. Summary of the invention

[0009] Problem that the invention aims to solve

[0010] An object of the present invention is to provide a polishing composition for semiconductor processing, a method for preparing the polishing composition, and a method for preparing a semiconductor element using the polishing composition.

[0011] Another object of the present invention is to provide a polishing composition for semiconductor process, which is supplied to the polishing process of an amorphous carbon film, has an excellent polishing rate for the amorphous carbon film, and prevents defects from being generated by preventing carbon residue from being adsorbed onto a substrate.

[0012] Another object of the present invention is to provide a method for preparing a polishing composition, which improves storage stability by stabilizing an accelerator in the polishing composition.

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

[0014] Means used to solve problems

[0015] To achieve the above-mentioned purpose, a semiconductor process polishing composition according to an embodiment of the present invention comprises polishing particles and a surfactant, and the value of the following formula 1 is 0.5 to 2,

[0016] Type 1:

[0017]

[0018] In the above formula 1, the thickness is When an amorphous carbon layer (ACL) is polished under a pressure of 2 psi for 60 seconds at a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is a measured value of the polishing rate, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0019] Another embodiment of the present invention provides a method for preparing a polishing composition for semiconductor processes, comprising the steps of adding a stabilizer and an accelerator to a solvent and mixing them to prepare a polishing solution, mixing a pH adjuster into the polishing solution to adjust the pH of the polishing solution, and mixing a surfactant and polishing particles into the polishing solution with adjusted pH.

[0020] A method for preparing a semiconductor element according to another embodiment of the present invention comprises the following steps: 1) providing a polishing pad comprising a polishing layer, 2) supplying a polishing composition for semiconductor process to the polishing pad; and 3) polishing the polishing object while the polishing surface of the polishing layer contacts the polishing surface of the polishing object and the polishing composition comprises polishing particles and a surfactant.

[0021] Effects of the Invention

[0022] The present invention is applicable to the CMP process of an amorphous carbon film, has an excellent polishing rate, can prevent carbon residues generated during the polishing process from being adsorbed to a semiconductor substrate, prevents contamination of a polishing pad, and has excellent storage stability.

[0023] In addition, a method for producing a semiconductor element using the polishing composition for semiconductor process can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 2 Graph 1 is a surface tension measurement result of an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention relates to a polishing composition for semiconductor process, which comprises polishing particles and a surfactant, and the value of the following formula 1 is 0.5 to 2,

[0027] Type 1:

[0028]

[0029] In the above formula 1, the thickness is When an amorphous carbon layer (ACL) is polished under a pressure of 2 psi for 60 seconds at a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is a measured value of the polishing rate, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0030] Below, the embodiments of the present invention are described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be embodied in various forms and should not be construed as being limited to the embodiments described herein.

[0031] In the present specification, when it is described that a component “includes” another component, unless otherwise described to the contrary, it means that the other components may also be included, rather than excluding the other components.

[0032] In this specification, when it is described that one component is “connected” to another component, it includes not only the case of being “directly connected” but also the case of being “connected with other component interposed therebetween”.

[0033] In this specification, "B is located on A" means that B is located on A in direct contact with A, or that B is located on A with another layer sandwiched between A and B, and is not limited to the meaning that B is located on A in contact with the surface of A.

[0034] In the present specification, the term "combination thereof" included in the Markush type description refers to a mixture or combination of one or more selected from the group consisting of a plurality of constituent elements of the Markush type description, thereby indicating that one or more selected from the group consisting of the plurality of constituent elements is included.

[0035] In the present specification, the description of "A and / or B" means "A, B, or A and B".

[0036] In this specification, unless otherwise specified, terms such as "first", "second" or "A", "B", etc. are used to distinguish the same terms from each other.

[0037] In the present specification, unless otherwise specified, a singular expression may be construed as including a singular or plural meaning as interpreted by the context.

[0038] Hereinafter, the present invention will be described in more detail.

[0039] As semiconductor components become more miniaturized and denser, the surface structure becomes more complex. The complexity of the surface structure refers to the narrowing of semiconductor line width and the gradual increase of aspect ratio. In order to match the increasing aspect ratio, the photoresist is also gradually becoming thinner.

[0040] However, the thin and long photoresist cannot withstand the etching process and collapses. In order to prevent this, the hard mask process was introduced.

[0041] As the hard mask material, amorphous carbon and SiON are used.

[0042] When the amorphous carbon is used as a hard mask, even if it has excellent etching resistance, when a chemical mechanical polishing process is performed using an existing polishing composition, due to the low polishing rate and the generation of carbon residue, the carbon residue is adsorbed on the film surface, thereby causing defects in the semiconductor substrate.

[0043] Compared with the existing polishing composition, the polishing composition for semiconductor process of the present invention has excellent polishing rate for the amorphous carbon film and can prevent carbon residues from being adsorbed on the film surface, thereby preventing defects of the semiconductor substrate from being generated.

[0044] Specifically, the semiconductor process polishing composition of the present invention comprises polishing particles and a surfactant, and the value of the following formula 1 is 0.5 to 2,

[0045] Type 1:

[0046]

[0047] In the above formula 1, the thickness is When the amorphous carbon film is pressurized at 2 psi for 60 seconds and polished under the conditions of a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is the polishing rate measurement value, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0048] The polishing composition for semiconductor process of the present invention comprises polishing particles and a surfactant, and has an excellent polishing rate in the polishing process of the amorphous carbon film, and reduces the surface tension, thereby preventing the re-adsorption of carbon residues to the semiconductor substrate.

[0049] More specifically, the existing polishing composition has a low polishing rate for amorphous carbon films. When used in a polishing process, the polishing time is long and there is a problem of low polishing efficiency.

[0050] Here, in order to improve the polishing rate of an amorphous carbon film, a method for improving the polishing rate of an amorphous carbon film by including the following accelerator in a polishing composition is proposed. Although the polishing rate of an amorphous carbon film is improved by including the accelerator in the polishing composition, the carbon residue generated during the polishing process is re-adsorbed onto the semiconductor substrate, resulting in an increase in defects on the semiconductor substrate.

[0051] In order to solve the problem of defect generation, the semiconductor process polishing composition of the present invention includes a surfactant to reduce the surface tension of the polishing composition. As described above, by including a surfactant, carbon residues generated during the polishing process can be prevented from being re-adsorbed onto the surface of the semiconductor substrate, thereby preventing defects from being generated on the semiconductor substrate.

[0052] Polishing composition for semiconductor manufacturing process, with a polishing rate of amorphous carbon film Preferably to More preferably to However, the present invention is not limited to the above examples. When a polishing process of an amorphous carbon film is performed within the scope of the present invention, a highly efficient polishing composition can be provided.

[0053] The following formula 1 is a formula regarding the relationship among the polishing rate, polishing particles, and surfactant of the polishing composition of the present invention:

[0054] Type 1:

[0055]

[0056] In the above formula 1, the thickness is When the amorphous carbon film is pressurized at 2 psi for 60 seconds and polished under the conditions of a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is the polishing rate measurement value, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0057] Specifically, the value of the first formula is 0.5 to 2, preferably 0.7 to 1.4. When the value of the first formula falls within the range of the present invention, the polishing rate of the amorphous carbon film can be improved and surface defects of the semiconductor substrate can be prevented.

[0058] In the relationship of the first formula, the denominator value is related to the content of the polishing particles and the surfactant. The surfactant is contained in a small amount in the polishing composition to reduce the surface tension of the polishing composition.

[0059] Specifically, in the denominator value, 100 represents the content range of the polishing particles, that is, 100 parts by weight. In addition, in the denominator value, S of 100S represents the weight parts of the surfactant relative to 100 parts by weight of the polishing particles, and 100 is a coefficient for reflecting the effect of the surfactant on suppressing the generation of surface defects of the semiconductor substrate during the polishing process.

[0060] When the value of the first formula falls within the range of the present invention, the polishing rate of the amorphous carbon film is excellent, and carbon residues can be prevented from being re-adsorbed on the surface of the semiconductor substrate during the polishing process, thereby suppressing the generation of defects in the semiconductor substrate.

[0061] The polishing composition contains 0.5 to 5 parts by weight of the surfactant, preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the metal oxide particles. When mixed and used within the above range, the value according to the first formula falls within the scope of the present invention, and the polishing rate of the amorphous carbon film is excellent, and it is possible to prevent carbon residues from being re-adsorbed onto the surface of the semiconductor substrate during the polishing process, thereby suppressing the generation of defects in the semiconductor substrate.

[0062] The surfactant is not particularly limited as long as it can play a role in preventing carbon residues from being re-adsorbed onto the surface of the semiconductor substrate during the polishing process.

[0063] Specifically, the surfactant may include a nonionic fluorine-based polymer compound. The surfactant includes a fluorine-based polymer compound, and when used in the polishing process of the amorphous carbon film, it can prevent the generated carbon residue from being re-adsorbed onto the surface of the semiconductor substrate. In addition, the surfactant contains fluorine, which can inhibit the reproduction of microorganisms such as bacteria and molds. When the polishing composition is stored for a long time, bacteria and molds may be generated. The polishing composition that produces the bacteria and molds cannot be used in the polishing process and needs to be discarded. The surfactant of the polishing composition of the present invention includes a nonionic fluorine-based polymer compound, which can prevent the generation of bacteria and molds when the polishing composition is stored for a long time, and can improve the long-term storage stability.

[0064] The surfactant of the present invention can be selected from Chemours tm )'s FS-30, FS-31, FS-34, ET-3015, ET-3150, ET-3050 and a mixture thereof, but there is no particular limitation as long as the substance can prevent the carbon residue from being re-adsorbed onto the surface of the semiconductor substrate during the polishing process.

[0065] The surfactant of the present invention is a nonionic surfactant. The surfactant including the nonionic fluorine-based polymer compound may be used alone or in combination with other nonionic surfactants.

[0066] The nonionic surfactant may be selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene-propylene copolymer, polyalkyl oxide, polyoxyethylene oxide (PEO), polyethylene oxide, and polypropylene oxide; the fluorine-based surfactant may 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, ethylene oxide / propylene oxide fluorosurfactant. The present invention is a group consisting of a fluorosurfactant and a polyoxyethylene fluorosurfactant.

[0067] The polishing particles are polishing particles that can be used in polishing compositions for semiconductor processes, for example, can be selected from the group consisting of metal oxides, organic particles, organic-inorganic composite particles and mixtures thereof, the metal oxides can be selected from the group consisting of colloidal silica, fumed silica, cerium dioxide, alumina, titanium dioxide, zirconium dioxide, zeolite and mixtures thereof, without being limited to the examples described above, and all polishing particles that can be selected by those skilled in the art can be used without restriction.

[0068] The organic particles are: polystyrene, styrene copolymers, poly(meth)acrylates, (meth)acrylate copolymers, polyvinyl chloride, polyamide, polycarbonate, polyimide polymers; or particles of a core / shell structure in which the polymers constitute a core, a shell, or both. These can be used alone or in combination. The organic particles can be prepared by emulsion polymerization, suspension polymerization, etc.

[0069] The polishing particles of the present invention may be specifically selected from the group consisting of colloidal silica, fumed silica, cerium dioxide, and a mixture thereof.

[0070] The diameter of the polishing particles (D 50 ) is 10 nm to 120 nm, preferably, the diameter (D 50 ) may be 20 nm to 100 nm, more preferably, the diameter (D 50 ) can be 20nm to 60nm. When the diameter of the polishing particle (D 50 ) falls within the above range, it is possible to reduce defects such as scratches in the polishing target substrate, etc., and to improve the dispersibility of the polishing particles. Specifically, when polishing particles within the above diameter range are used, the dispersibility of the particles is improved, so that agglomeration between particles in the polishing composition does not occur, and it is possible to prevent defects such as scratches caused by the polishing particles.

[0071] The polishing composition may further include an accelerator, a stabilizer, and a pH adjuster.

[0072] The accelerator can be selected from the group consisting of anionic low molecular weight, anionic high molecular weight, hydroxy acid, amino acid and cerium salt. Specifically, the cerium salt can be a trivalent cerium salt or a tetravalent cerium salt. More specifically, the tetravalent cerium salt can be selected from the group consisting of cerium (IV) sulfate (Ce(SO4)2), ammonium cerium sulfate dihydrate and ammonium cerium nitrate (Cerium Ammonium Nitrate), but is not limited to the examples.

[0073] The accelerator is included in the polishing composition to oxidize the surface layer of the amorphous carbon film by oxide or ion, thereby facilitating removal of the surface layer of the amorphous carbon film.

[0074] In addition, by making it possible to easily remove the residue of the organic film substance present in the polishing stop film layer, there is an advantage that more uniform polishing can be achieved.

[0075] The ammonium cerium nitrate may be present in the slurry composition in the form of an ionic compound or a chelate compound, and when used in the above-mentioned form, it can provide a high polishing rate for an amorphous carbon film.

[0076] The polishing composition of the present invention comprises an accelerator and a stabilizer to improve the polishing rate of an amorphous carbon film. The accelerator can not only show a high polishing rate of the amorphous carbon film, but also the stabilizer can be used to achieve long-term storage. Furthermore, during the polishing process, surface defects of the semiconductor substrate caused by the re-adsorption of carbon residues to the semiconductor substrate can be prevented.

[0077] Here, the present invention includes an accelerator and a stabilizer, wherein the accelerator is used to improve the polishing rate of the amorphous carbon film, and the stabilizer is used to improve the stability of the polishing composition, thereby preventing carbon residues from being re-adsorbed onto the semiconductor substrate during the polishing process, thereby preventing defects from being generated.

[0078] Specifically, the stabilizer is an amino acid, 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 a mixture thereof, preferably alanine, but not limited to the examples, as long as it can be mixed with an accelerator to improve the stability of the polishing composition and can inhibit the generation of defects in the polishing process, it can be used without restriction.

[0079] The pH adjuster may be at least one selected from the group consisting of 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, adipic acid, acetic acid, propionic acid, fumaric acid, oleic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid and potassium hydroxide.

[0080] The pH adjuster can adjust the pH of the semiconductor process polishing composition to 2 to 5, preferably 2 to 4. When the acidic environment is maintained in this range, excessive corrosion of metal components or polishing equipment can be prevented while maintaining the polishing speed and quality above a certain level.

[0081] The accelerator can be used in an amount of 400 to 800 parts by weight based on 100 parts by weight of the polishing particles of the polishing composition. Specifically, the accelerator can be used in an amount of 450 to 700 parts by weight, for example, 450 to 550 parts by weight, based on 100 parts by weight of the polishing particles of the polishing composition.

[0082] The stabilizer can be used in an amount of 350 to 750 parts by weight based on 100 parts by weight of the polishing particles of the polishing composition. Specifically, the stabilizer can be used in an amount of 400 to 600 parts by weight, for example, 430 to 500 parts by weight, based on 100 parts by weight of the large polishing particles of the polishing composition.

[0083] The surfactant can be used in an amount of 0.4 to 5 parts by weight based on 100 parts by weight of the polishing particles of the polishing composition. Specifically, the surfactant can be used in an amount of 0.5 to 2 parts by weight, for example, 0.6 to 1.5 parts by weight, based on 100 parts by weight of the polishing particles of the polishing composition.

[0084] The accelerator, the stabilizer, and the surfactant may be mixed in a solvent and provided in the form of the polishing composition.

[0085] The solvent is ultrapure water, but the solvent is not limited to the above example, and any solvent that can be used as a solvent for a polishing composition can be used without limitation.

[0086] When the accelerator is contained in the polishing composition within the above range, the accelerator is stabilized by the stabilizer, the polishing rate can be improved by the accelerator in the polishing composition, and the long-term storage property can also be improved.

[0087] In addition, the stabilizer and the surfactant can prevent defects from being generated in a polishing process using the polishing composition.

[0088] When the content of the surfactant is lower than the range value, the generation of surface defects of the semiconductor substrate in the polishing process will increase. When the content exceeds the range value, there is a problem of generating a large amount of foam when preparing the polishing composition.

[0089] The solid content of the semiconductor process polishing composition is about 5 wt % to about 20 wt %. When the solid content is too low, the polishing rate of the amorphous carbon film may not be fully ensured, and when the solid content is too high, defects may occur due to the agglomeration of the polishing particles. That is, when the semiconductor process polishing composition contains the aforementioned components and the solvent and satisfies the solid content in the above range, it is beneficial to inject the semiconductor process polishing composition at a uniform flow rate when it is applied to the polishing process, and it is beneficial to ensure uniform dispersion and storage stability during the circulation and storage of the semiconductor process polishing composition.

[0090] The method for preparing a semiconductor process polishing composition of the present invention comprises the following steps: adding a stabilizer and an accelerator to a solvent and mixing them to prepare a polishing solution, mixing a pH adjuster into the polishing solution to adjust the pH of the polishing solution, and mixing a surfactant and polishing particles into the polishing solution with adjusted pH; the value of the semiconductor process polishing composition according to the following formula 1 is 0.5 to 2,

[0091] Type 1:

[0092]

[0093] In the above formula 1, the thickness is When the amorphous carbon film is pressurized at 2 psi for 60 seconds and polished under the conditions of a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is the polishing rate measurement value, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0094] In order to stabilize the accelerator, in the step of preparing the polishing solution, a stabilizer may be mixed in a solvent to prepare a first polishing solution, and then an accelerator may be mixed to prepare a polishing solution.

[0095] When the accelerator is mixed with a stabilizer, a pH adjuster, a surfactant and polishing particles in ultrapure water as a solvent and prepared, the accelerator is unstable and is difficult to store for a long time when prepared into a polishing composition, and the polishing rate increase effect of the amorphous carbon film by the accelerator is not shown.

[0096] In order to prevent such a problem, after a stabilizer is mixed in a solvent to prepare a first polishing solution, an accelerator is dissolved in the first polishing solution to prepare a polishing solution. Thereafter, a pH adjuster is mixed in the polishing solution to adjust the pH of the polishing solution, and a surfactant and polishing particles are mixed in the pH-adjusted polishing solution to prepare a polishing composition. The polishing composition for semiconductor process prepared by the preparation method has an excellent polishing rate for amorphous carbon film by the accelerator, and has excellent stability and can be stored for a long time.

[0097] According to another embodiment of the present invention, a method for preparing a semiconductor element comprises the following steps: 1) providing a polishing pad including a polishing layer, 2) supplying a polishing composition for semiconductor process to the polishing pad; and 3) polishing the polishing object while the polishing surface of the polishing layer contacts the polishing surface of the polishing object and the polishing composition comprises polishing particles and a surfactant, wherein the value of the semiconductor process polishing composition according to the following formula 1 is 0.5 to 2,

[0098] Type 1:

[0099]

[0100] In the above formula 1, the thickness is When the amorphous carbon film is pressurized at 2 psi for 60 seconds and polished under the conditions of a carrier speed of 87 rpm, a platen speed of 93 rpm and an inflow rate of the polishing composition of 200 ml / min, Ra is the polishing rate measurement value, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0101] Figure 1 A schematic process diagram showing a semiconductor device manufacturing process according to an embodiment of the present invention. Figure 1 The polishing pad 110 of the embodiment is placed on a plate 120, and a semiconductor substrate 130 to be polished is placed on the polishing pad 110. For polishing, polishing slurry 150 is sprayed on the polishing pad 110 through a nozzle 140.

[0102] The flow rate of the polishing slurry 150 supplied through the nozzle 140 may be about 10 cm 3 / min to about 1000cm 3 / min range is selected according to the purpose, for example, it can be about 50cm 3 / min to about 500cm 3 / min, but not limited to this.

[0103] The polished surface of the semiconductor substrate 130 directly contacts the polishing surface of the polishing pad 110 .

[0104] Afterwards, the semiconductor substrate 130 and the polishing pad 110 rotate relative to each other, so that the surface of the semiconductor substrate 130 can 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 direction, or opposite directions. The rotation speeds of the semiconductor substrate 130 and the polishing pad 110 can be selected from the range of about 10 rpm to about 500 rpm according to the purpose, for example, about 30 rpm to about 200 rpm, but are not limited thereto.

[0105] As an example of a substrate polishing process, the substrate to be polished is an organic film, and the process can be applied to a polishing process of a carbon-based organic film.

[0106] Specifically, the carbon-based organic film may be exemplified by a carbon spin on hardmask (SOH) film, an amorphous carbon film or an NCP film, and preferably, may be an amorphous carbon film having an excellent selective polishing effect and a high polishing rate.

[0107] The specific description of the polishing composition for semiconductor process overlaps with the above description, and thus will be omitted.

[0108] In one implementation example, in order to maintain the polishing surface of the polishing pad 110 in a state suitable for polishing, the method for preparing a semiconductor element further includes a step of processing the polishing surface of the polishing pad 110 by a dresser 170 while polishing the semiconductor substrate 130 .

[0109] Preparation of semiconductor polishing composition

[0110] Example 1

[0111] Alanine as a stabilizer was mixed into ultrapure water to prepare a first polishing solution. Cerium ammonium nitrate as an accelerator was mixed into the first polishing solution to prepare a polishing solution.

[0112] Nitric acid was mixed into the polishing solution, the pH was adjusted to 2.1, and Chemours (Chemours tm ) company's FS-30 and colloidal silica with a diameter of 75 nm to prepare a polishing composition.

[0113] Example 2

[0114] A polishing composition was prepared in the same manner as in Example 1, except that 2 parts by weight of the surfactant was contained relative to 100 parts by weight of the colloidal silica.

[0115] Example 3

[0116] A polishing composition was prepared in the same manner as in Example 1, except that histidine was used instead of the alanine.

[0117] Example 4

[0118] A polishing composition was prepared in the same manner as in Example 1, except that proline was used instead of the alanine.

[0119] Example 5

[0120] A polishing composition was prepared in the same manner as in Example 1, except that arginine was used instead of the alanine.

[0121] Comparative Example 1

[0122] Ultrapure water was used as Comparative Example 1.

[0123] Comparative Example 2

[0124] A polishing composition was prepared in the same manner as in Example 1, except that no surfactant was additionally included.

[0125] Comparative Example 3

[0126] A polishing composition was prepared in the same manner as in Example 1, except that a pyridinium salt as a cationic surfactant was used as a surfactant.

[0127] Comparative Example 4

[0128] A polishing composition was prepared in the same manner as in Example 1, except that Tween 20, which is a nonionic surfactant, was used as a surfactant.

[0129] The specific contents of Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 1 below.

[0130] [Table 1]

[0131]

[0132]

[0133] (Unit weight %)

[0134] Experimental Example 1

[0135] Measurement of surface tension

[0136] Ultrapure water was used as a control group, and the bubble life time was measured for Comparative Example 1, Example 1, and Example 2 to evaluate the surface tension.

[0137] As a measuring instrument, a bubble pressure tension meter from SITA was used. During the measurement, the sample volume was adjusted to 100 ml, and the bubble age on the liquid surface was measured based on the surface tension. The results are as follows: Figure 2 shown.

[0138] It was confirmed that the specific surface tension value of ultrapure water used as the control group did not change as the bubble age increased.

[0139] It was confirmed that the surface tension of Comparative Example 1, Example 1, and Example 2 decreased as the age of the bubbles passing through the components of the polishing composition increased compared to the control group, but the surface tension decreased as the content of the surfactant increased compared to Comparative Example 1. Specifically, as the surface tension decreases, carbon residues can be prevented from being re-adsorbed onto the substrate surface, which can mean that defects generated on the semiconductor substrate can be reduced during the polishing process.

[0140] On the contrary, in Comparative Examples 2 to 4, although polishing compositions were prepared by differentiating the types of surfactants, further evaluation experiments could not be performed because agglomeration occurred in the polishing compositions.

[0141] Experimental Example 2

[0142] Polishing rate and whether there are defects on the surface of the semiconductor substrate

[0143] In order to confirm the polishing rate when the polishing composition of the present invention is used in a polishing process and whether defects occur on the surface of a semiconductor substrate, a polishing process is performed to measure the polishing rate and confirm whether defects occur on the surface.

[0144] The specific polishing process conditions are: The amorphous carbon layer (ACL) was pressurized at 2 psi for 60 seconds, the carrier speed was 87 rpm, the platen speed was 93 rpm, and the inflow flow rate of the polishing composition was 200 ml / min.

[0145] The polishing rate of the amorphous carbon film under the above polishing conditions was measured, and whether defects were generated was confirmed using KLA Tencor AIT-XP+.

[0146] The value of the first formula calculated by the measured polishing rate, the polishing particles and the weight parts of the surfactant is as follows:

[0147] Type 1:

[0148]

[0149] Wherein, Ra is the polishing rate measurement value, and S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

[0150] [Table 2]

[0151]

[0152] Referring to Table 2, when comparing Comparative Example 2 and Examples, the polishing rate of the amorphous carbon film does not show a significant difference. Specifically, the polishing rates of Examples 1 to 5 for the amorphous carbon film exceed The polishing rate of the same level was also shown in the comparison result with Comparative Example 2. However, it was confirmed that the number of defects generated in the polishing process of Comparative Example 2 was significantly larger than that of the Example.

[0153] According to the experimental results, it can be confirmed that the polishing rate of the amorphous carbon film is different due to the inclusion of the accelerator. The polishing rates of the amorphous carbon film of Examples 1 to 5 and Comparative Example 2, which all contain the accelerator, are more than However, it can be confirmed that in the absence of surfactant, the carbon residue increases and therefore the total number of defects also increases.

[0154] As a result, Examples 1 to 5 satisfying the value of the first formula have excellent polishing rates for amorphous carbon films and are excellent in the effect of preventing defects from being generated after the polishing process.

[0155] The preferred embodiments of the present invention are described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements by ordinary technicians in the technical field of the present invention using the basic concepts of the present invention defined in the claims also fall within the scope of the present invention.

[0156] Description of Reference Numerals

[0157] 110: Polishing pad

[0158] 120: Tablet

[0159] 130: Semiconductor substrate

[0160] 140: Nozzle

[0161] 150: Polishing slurry

[0162] 160: Polishing head

[0163] 170: Dresser

[0164] Industrial Applicability

[0165] The present invention relates to a polishing composition for semiconductor process, a method for preparing the polishing composition, and a method for preparing a semiconductor element using the polishing composition.

Claims

1. A polishing composition for semiconductor processing, wherein: Contains polishing particles, accelerators, stabilizers and surfactants. The accelerator includes a cerium salt, The stabilizer is an amino acid, The surfactant is a nonionic fluorine-based polymer compound. Based on 100 parts by weight of the polishing particles of the polishing composition, 350 parts by weight to 750 parts by weight of the stabilizer are included. Based on 100 parts by weight of the polishing particles of the polishing composition, 400 to 800 parts by weight of the accelerator are included. The polishing composition comprises 0.5 to 5 parts by weight of the surfactant relative to 100 parts by weight of the polishing particles, The solid content of the semiconductor process polishing composition is 5 wt % to 20 wt %. According to the following formula 1, the value is 0.5 to 2, Formula 1: In the first formula, The thickness is When the amorphous carbon film is polished under the conditions of 2 psi pressure for 60 seconds, a carrier speed of 87 rpm, a platen speed of 93 rpm, and an inflow rate of the polishing composition of 200 ml / min, The Ra is a measurement of the polishing rate, The S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

2. The semiconductor process polishing composition according to claim 1, wherein The polishing particles are selected from the group consisting of metal oxides, organic particles, organic-inorganic composite particles, and mixtures thereof.

3. The semiconductor process polishing composition according to claim 1, wherein The polishing composition comprises a pH adjuster.

4. A method for preparing a polishing composition for semiconductor processing, wherein: The steps include: A stabilizer and an accelerator are added to the solvent and mixed to prepare a polishing solution. mixing a pH adjuster into the polishing solution to adjust the pH of the polishing solution, and mixing a surfactant and polishing particles in the polishing solution whose pH is adjusted; The accelerator includes a cerium salt, The stabilizer is an amino acid, The surfactant is a nonionic fluorine-based polymer compound. Based on 100 parts by weight of the polishing particles of the polishing composition, 350 parts by weight to 750 parts by weight of the stabilizer are included. Based on 100 parts by weight of the polishing particles of the polishing composition, 400 to 800 parts by weight of the accelerator are included. The polishing composition comprises 0.5 to 5 parts by weight of the surfactant relative to 100 parts by weight of the polishing particles, The solid content of the semiconductor process polishing composition is 5 wt % to 20 wt %, and the value of the semiconductor process polishing composition according to the following formula 1 is 0.5 to 2, Formula 1: In the first formula, The thickness is When the amorphous carbon film is polished under the conditions of 2 psi pressure for 60 seconds, a carrier speed of 87 rpm, a platen speed of 93 rpm, and an inflow rate of the polishing composition of 200 ml / min, The Ra is a measurement of the polishing rate, The S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

5. The method for preparing a semiconductor process polishing composition according to claim 4, wherein: In the step of preparing the polishing solution, A stabilizer is mixed in a solvent to prepare a first polishing solution, and an accelerator is mixed in the first polishing solution.

6. A method for preparing a semiconductor element, wherein: The steps include: 1) providing a polishing pad including a polishing layer, 2) supplying a polishing composition for semiconductor processing to the polishing pad; and 3) polishing the polishing object while the polishing surface of the polishing layer contacts the polishing surface of the polishing object and the polishing layer rotates relative to the polishing object; The polishing composition comprises polishing particles, an accelerator, a stabilizer and a surfactant. The accelerator includes a cerium salt, The stabilizer is an amino acid, The surfactant is a nonionic fluorine-based polymer compound. Based on 100 parts by weight of the polishing particles of the polishing composition, 350 parts by weight to 750 parts by weight of the stabilizer are included. Based on 100 parts by weight of the polishing particles of the polishing composition, 400 to 800 parts by weight of the accelerator are included. The polishing composition comprises 0.5 to 5 parts by weight of the surfactant relative to 100 parts by weight of the polishing particles, The solid content of the semiconductor process polishing composition is 5 wt % to 20 wt %, and the value of the semiconductor process polishing composition according to the following formula 1 is 0.5 to 2, Formula 1: In the first formula, The thickness is When the amorphous carbon film is polished under the conditions of 2 psi pressure for 60 seconds, a carrier speed of 87 rpm, a platen speed of 93 rpm, and an inflow rate of the polishing composition of 200 ml / min, The Ra is a measurement of the polishing rate, The S is the weight part of the surfactant relative to 100 weight parts of the polishing particles.

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