CN112216607A - Silicon nitride film etching solution and method for manufacturing semiconductor device using the same - Google Patents
Silicon nitride film etching solution and method for manufacturing semiconductor device using the same Download PDFInfo
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- CN112216607A CN112216607A CN202010626275.1A CN202010626275A CN112216607A CN 112216607 A CN112216607 A CN 112216607A CN 202010626275 A CN202010626275 A CN 202010626275A CN 112216607 A CN112216607 A CN 112216607A
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- 238000005530 etching Methods 0.000 title claims abstract description 97
- 229910052581 Si3N4 Inorganic materials 0.000 title claims abstract description 90
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 title claims abstract description 90
- 238000000034 method Methods 0.000 title claims abstract description 33
- 239000004065 semiconductor Substances 0.000 title claims abstract description 14
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 165
- 239000008119 colloidal silica Substances 0.000 claims abstract description 89
- 239000002245 particle Substances 0.000 claims abstract description 76
- 239000000243 solution Substances 0.000 claims description 61
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 49
- 229910052710 silicon Inorganic materials 0.000 claims description 49
- 239000010703 silicon Substances 0.000 claims description 49
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 34
- 239000000654 additive Substances 0.000 claims description 34
- 230000000996 additive effect Effects 0.000 claims description 34
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 17
- 150000001875 compounds Chemical class 0.000 claims description 13
- 229910052731 fluorine Inorganic materials 0.000 claims description 12
- 239000011737 fluorine Substances 0.000 claims description 12
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- MIMUSZHMZBJBPO-UHFFFAOYSA-N 6-methoxy-8-nitroquinoline Chemical compound N1=CC=CC2=CC(OC)=CC([N+]([O-])=O)=C21 MIMUSZHMZBJBPO-UHFFFAOYSA-N 0.000 claims description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 4
- 150000002892 organic cations Chemical class 0.000 claims description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 3
- 229910000040 hydrogen fluoride Inorganic materials 0.000 claims description 3
- 150000001450 anions Chemical class 0.000 claims 1
- 229910052814 silicon oxide Inorganic materials 0.000 abstract description 41
- 239000011856 silicon-based particle Substances 0.000 abstract description 9
- 230000002776 aggregation Effects 0.000 abstract description 2
- 238000004220 aggregation Methods 0.000 abstract description 2
- 239000000377 silicon dioxide Substances 0.000 description 16
- 238000002360 preparation method Methods 0.000 description 15
- -1 silane compound Chemical class 0.000 description 14
- 239000000758 substrate Substances 0.000 description 13
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 10
- 239000010410 layer Substances 0.000 description 9
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000002156 mixing Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 238000001039 wet etching Methods 0.000 description 5
- 125000000217 alkyl group Chemical group 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 125000005210 alkyl ammonium group Chemical group 0.000 description 2
- 238000000231 atomic layer deposition Methods 0.000 description 2
- 239000005380 borophosphosilicate glass Substances 0.000 description 2
- 239000005388 borosilicate glass Substances 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 2
- 238000001312 dry etching Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000002608 ionic liquid Substances 0.000 description 2
- 239000005360 phosphosilicate glass Substances 0.000 description 2
- 229920001709 polysilazane Polymers 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229910000077 silane Inorganic materials 0.000 description 2
- 239000005368 silicate glass Substances 0.000 description 2
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- RAXXELZNTBOGNW-UHFFFAOYSA-O Imidazolium Chemical compound C1=C[NH+]=CN1 RAXXELZNTBOGNW-UHFFFAOYSA-O 0.000 description 1
- RWRDLPDLKQPQOW-UHFFFAOYSA-O Pyrrolidinium ion Chemical compound C1CC[NH2+]C1 RWRDLPDLKQPQOW-UHFFFAOYSA-O 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O ammonium group Chemical group [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000005365 phosphate glass Substances 0.000 description 1
- 239000006187 pill Substances 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/31051—Planarisation of the insulating layers
- H01L21/31053—Planarisation of the insulating layers involving a dielectric removal step
- H01L21/31055—Planarisation of the insulating layers involving a dielectric removal step the removal being a chemical etching step, e.g. dry etching
- H01L21/31056—Planarisation of the insulating layers involving a dielectric removal step the removal being a chemical etching step, e.g. dry etching the removal being a selective chemical etching step, e.g. selective dry etching through a mask
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
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- C09K13/00—Etching, surface-brightening or pickling compositions
- C09K13/04—Etching, surface-brightening or pickling compositions containing an inorganic acid
- C09K13/06—Etching, surface-brightening or pickling compositions containing an inorganic acid with organic material
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/30604—Chemical etching
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- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31105—Etching inorganic layers
- H01L21/31111—Etching inorganic layers by chemical means
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Abstract
The present invention relates to a silicon nitride film etching solution and a method for manufacturing a semiconductor device using the same, and more particularly, to a silicon nitride film etching solution and a method for manufacturing a semiconductor device using the same, in which the silicon nitride film etching solution includes second colloidal silica particles having a surface area increased compared to that of spherical first colloidal silica particles having the same volume as a reference, and thus, the aggregation phenomenon of the colloidal silica particles can be prevented even at a high temperature, thereby preventing the generation of silicon-based particles, and the etching selectivity of a silicon nitride film with respect to a silicon oxide film under etching conditions can be improved.
Description
Technical Field
The present invention relates to a silicon nitride film etching solution and a method for manufacturing a semiconductor device using the same, and more particularly, to a silicon nitride film etching solution which prevents generation of particles and increases a selectivity of a silicon nitride layer with respect to a silicon oxide film, and a method for manufacturing a semiconductor device using the same.
Background
At present, there are various methods for etching a silicon nitride film and a silicon oxide film, and a dry etching method and a wet etching method are mainly used.
In general, the dry etching method is an etching method using a gas, has an advantage of isotropically outstanding compared to the wet etching method, but has a productivity far lower than that of the wet etching method and is an expensive way, and thus the wet etching method tends to be widely used.
In general, a method using phosphoric acid as an etching solution as a wet etching method is well known. In this case, when only pure phosphoric acid is used to etch the silicon nitride film, problems such as various defects and pattern abnormalities may occur due to etching of not only the silicon nitride film but also the silicon oxide film as the device is miniaturized, and therefore, it is necessary to further reduce the etching rate of the silicon oxide film by forming a protective film on the silicon oxide film.
Disclosure of Invention
Problems to be solved by the invention
An object of the present invention is to provide a silicon nitride film etching solution in which generation of particles is prevented by increasing the surface area of colloidal silica particles contained in a silicon additive in a silicon substrate etching solution, and the selectivity of the silicon nitride film to a silicon oxide film is increased under etching conditions.
Another object of the present invention is to provide a method for manufacturing a semiconductor device using the silicon nitride film etching solution.
Means for solving the problems
In order to solve the above problems, according to an embodiment of the present invention, there is provided a silicon nitride film etching solution including an aqueous phosphoric acid solution and a silicon additive. The silicon additive contains spherical first colloidal silica and second colloidal silica particles, and the surface area of the second colloidal silica particles is greater than 100% and 124% or less based on the surface area of the spherical first colloidal silica particles on the basis of the same volume, and the content of the second colloidal silica particles contained in the silicon additive is 50% or more.
Further, according to another embodiment of the present invention, there is provided a method for manufacturing a semiconductor device using the silicon nitride film etching solution.
Effects of the invention
The silicon nitride film etching solution of the present invention contains the second colloidal silica particles having an increased surface area as compared with the spherical first colloidal silica particles having the same volume as the reference, and therefore, can prevent the generation of silicon-based particles by preventing the aggregation of the colloidal silica particles at a high temperature.
Also, the second colloidal silica particles used in the present application, which have an increased surface area, have an increased exposure amount of hydroxyl groups (-OH) as compared to the spherical first colloidal silica particles, and can improve the etching selectivity of the silicon nitride film with respect to the silicon oxide film under etching conditions.
Drawings
Fig. 1 is a cross-sectional view schematically showing a silicon nitride film removal process using an etching solution according to an embodiment of the present invention.
Description of reference numerals:
10: silicon substrate
11: silicon nitride film
12: silicon oxide film
20: laminated structure
30: mask pattern layer
50: and (4) a groove.
Detailed Description
The advantages, features, and methods of accomplishing the same of the present invention will become more apparent with reference to the following examples. However, the present invention is not limited to the embodiments described below, and can be implemented in various different ways, and the embodiments are only for making the disclosure of the present invention complete, and the present invention is provided to enable those skilled in the art to fully understand the scope of the present invention, and the present invention is limited only by the scope of the claims.
Hereinafter, the silicon nitride film etching solution and the method for preparing the same according to the present invention will be described in detail.
In general, in order to protect the silicon oxide film in the phosphoric acid aqueous solution, the silicon nitride film etching solution may contain a silicon additive using spherical (Sphere) colloidal silica particles. The colloidal silica particles in the etching solution can aggregate with each other and grow into silicon-based particles. When silicon-based particles are grown, they are the largest cause of defects in the silicon substrate.
Further, since the spherical colloidal silica particles have a low exposure amount of hydroxyl group (-OH), they cannot sufficiently function as a protective layer (passivation layer) for a silicon oxide film, and thus there is a problem that the selectivity of silicon nitride film to silicon oxide film is lowered.
In order to solve the above problems, an embodiment of the present invention provides a silicon nitride film etching solution including an aqueous phosphoric acid solution and a silicon additive, wherein the silicon additive includes spherical first colloidal silica and second colloidal silica particles. The surface area of the second colloidal silica particles is greater than 100% and not greater than 124% with respect to the surface area of the spherical first colloidal silica particles on the basis of the same volume. The content of the second colloidal silica particles contained in the silicon additive is 50% or more, and the growth of silicon-based grains can be suppressed even when the temperature is increased while increasing the selectivity of the silicon additive to the silicon nitride film.
The second colloidal silica particles of the present invention may have a shape of spherical colloidal silica particles changed, and have a surface area increased compared to the first colloidal silica particles based on the same volume, and may have an ellipsoidal, polyhedral, pill, or rugby ball shape, for example.
That is, in the second colloidal silica particles of the present invention, the shape of the spherical first colloidal silica particles is changed, and the deposition (stacking) of the silica particles is reduced even at high temperature, whereby the generation of silicon-based particles can be prevented. Further, generation of silicon-based particles can be prevented to reduce defects and device failures of devices formed on a silicon substrate.
The surface area of the second colloidal silica particles of the present invention is greater than 100% and not more than 124% with respect to the surface area of the spherical first colloidal silica particles, based on the same volume.
Wherein a surface area of the second colloidal silica particles of greater than 100% as compared to the surface area of the spherical first colloidal silica particles means an increase in surface area as compared to the same volume of the spherical first colloidal silica particles. The surface area of the second colloidal silica particles of the present application is 124% or less of the surface area of the spherical first colloidal silica particles, which means that the surface area of the second colloidal silica particles is not more than 124% of the surface area of the spherical first colloidal silica particles in the same volume.
When the surface area of the second colloidal silica particles is 100% or less as compared with the surface area of the spherical first colloidal silica particles having the same volume, the amount of hydroxyl groups exposed to the surface of the spherical first colloidal silica particles is not increased, and thus the effect of improving the etching selectivity with respect to the silicon oxide film to the silicon nitride film is insignificant. The second colloidal silica particles having a surface area of more than 124% in comparison with the surface area of the spherical first colloidal silica particles on the basis of the same volume are limited in preparation, and particles may be formed due to bonding between the silica particles.
Preferably, the surface area of the second colloidal silica particles of the present application may be 110% or more and 124% or less, compared to the surface area of the first colloidal silica particles based on the same volume of spheres. More preferably, the surface area of the second colloidal silica particles of the present application may be 115% or more and 120% or less, on the same volume basis, as compared with the surface area of the spherical first colloidal silica particles. The second colloidal silica particles of the present application have an effect of increasing the etching selectivity of the silicon nitride film with respect to the silicon oxide film as the surface area of the second colloidal silica particles increases, on the basis of the same volume, as compared with the surface area of the spherical first colloidal silica particles.
That is, in the second colloidal silica particles of the present application, since the shape of the spherical first colloidal silica particles is changed, the surface area is increased as compared with the first colloidal silica particles of the same volume, and thus, the hydroxyl group (-OH) exposed to the surface of the second colloidal silica particles is increased as compared with the first colloidal silica particles.
As such, the second colloidal silica particles of the present application can expose more hydroxyl groups than the spherical first colloidal silica particles. The hydroxyl groups combine with the silicon oxide film to form siloxane, which functions as a protective film for protecting the silicon oxide film in an aqueous phosphoric acid solution. Therefore, the second colloidal silica particles of the present application can form more siloxane by combining with the silicon oxide film, and can protect the silicon oxide film more effectively, compared to the first colloidal silica particles. Further, the silicon nitride film etching solution containing the second colloidal silica particles of the present application can improve the etching selectivity of the silicon nitride film with respect to the silicon oxide film.
And the content of the second colloidal silica particles contained in the silicon additive is 50% or more. For example, the silicon additive may include spherical first colloidal silica particles and second colloidal silica particles, and the content of the second colloidal silica particles in the silicon additive may be the same as or higher than the content of the spherical first colloidal silica particles. Preferably, the content of the second colloidal silica particles contained in the silicon additive may be 70% or more. More preferably, the content of the second colloidal silica particles contained in the silicon additive may be 90% or more. As another example, the silicon additive may not include the spherical first colloidal silica particles, and in this case, the content of the second colloidal silica particles included in the silicon additive may be 100%. When the content of the second colloidal silica particles contained in the silicon additive is less than 50%, silica stacking (stacking) may occur at high temperature, whereby silicon-based particles may be generated. In addition, when the content of the second colloidal silica particles contained in the silicon additive is less than 50%, the increase of hydroxyl groups exposed to the surface of the silica particles is small, and thus the etching selectivity of the silicon nitride film to the silicon oxide film is little improved.
Preferably, the silicon nitride film etching solution has 100ppm to 100000ppm of the above silicon additive. And, more preferably, the silicon nitride film etching solution has the above silicon additive in an amount of 100ppm to 10000 ppm. The amount of the silicon additive added is the amount of the silicon additive dissolved in the silicon nitride film etching solution, and is expressed in ppm units.
For example, having 100ppm of the silicon additive in the silicon nitride layer etching solution means that the silicon additive dissolved in the silicon nitride layer etching solution is 100 ppm.
In the case where the silicon additive in the silicon nitride film etching solution is less than 100ppm, the effect of increasing the etching selectivity ratio with respect to the silicon oxide film to the silicon nitride film may be slight due to the insufficient amount of the silane compound under the etching conditions.
In contrast, in the case where the silicon additive in the silicon nitride film etching solution is more than 100000ppm, the saturation concentration of the silane compound in the silicon nitride film etching solution increases, and therefore, a problem of generating silicon-based particles may occur.
Preferably, the silicon substrate comprises at least a silicon oxide film (SiO)x) And may contain both a silicon oxide film and a silicon nitride film. In the case of a silicon substrate including both a silicon oxide film and a silicon nitride film, the silicon substrate may be formed by alternately stacking the silicon oxide film and the silicon nitride film or stacked in different regions.
The silicon oxide film may be a Spin On Dielectric (SOD) film, a High Density Plasma (HDP) film, a thermal oxide film (thermal oxide), a borophosphosilicate Glass (borophosphosilicate Glass) film, a phosphosilicate Glass (phosphosilicate Glass) film, a BoroSilicate Glass (BSG) film, a Polysilazane (PSZ) film, a Fluorinated Silicate Glass (FSG) film, a Low Pressure TetraEthyl orthosilicate (LP-TEOS) film, a Low Pressure TetraEthyl orthosilicate (Low Pressure TetraEthyl orthosilicate) film, a Plasma Enhanced TetraEthyl orthosilicate (PETEOS), a thin modified TetraEthyl orthosilicate (Ethyl Silicate) film, a High temperature oxide (MTO) film, a High Temperature Oxide (HTO) film, a Medium Temperature Oxide (MTO) film, or a phosphate Glass film, depending On the application, the kind of material, etcTemperature Oxide) film, Undoped Silicate Glass (USG) film, Spin On Glass (SOG) film, Advanced Planarization film (APL), Atomic Layer Deposition (ALD) film, Plasma Enhanced Oxide (Plasma Enhanced Oxide) film, or O-Glass film3Tetraethylorthosilicate (O)3-TEOS，O3Tetra Ethyl Ortho Silicate) and the like.
The phosphoric acid aqueous solution is a component for etching the silicon nitride film and maintaining the pH of the etching solution to suppress the change of various forms of silicon compounds present in the etching solution into silicon-based particles.
In one embodiment, the phosphoric acid aqueous solution is preferably contained in an amount of 60 to 90 parts by weight relative to 100 parts by weight of the silicon nitride film etching solution.
When the content of the phosphoric acid aqueous solution is less than 60 parts by weight based on 100 parts by weight of the silicon nitride film etching solution, the etching rate of the silicon nitride film is lowered, and thus the silicon nitride film is not sufficiently etched or the efficiency of the etching process of the silicon nitride film is lowered.
Conversely, in the case where the content of the phosphoric acid aqueous solution is greater than 90 parts by weight with respect to 100 parts by weight of the silicon nitride film etching solution, as the etching rate of the silicon nitride film with respect to the silicon oxide film increases, the etching selectivity of the silicon nitride film with respect to the silicon oxide film may decrease, and a defect of the silicon substrate due to etching of the silicon oxide film may be caused.
The silicon nitride film etching solution according to an embodiment of the present invention may further include a fluorine-containing compound to compensate for a decreased etching rate with the use of a silicon additive and to improve the efficiency of the entire etching process.
In the present application, fluorine-containing compound means all compounds in any form capable of separating out fluorine ions.
In one embodiment, the fluorine-containing compound is at least one selected from the group consisting of hydrogen fluoride, ammonium bifluoride, and ammonium bifluoride.
In still another embodiment, the fluorine-containing compound may be a compound in which an organic cation and a fluorine anion are bonded to each other.
For example, the fluorine-containing compound may be a compound in which an alkylammonium salt and a fluorine anion are bonded. Wherein the alkyl ammonium salt is an ammonium having at least one alkyl group and may have up to four alkyl groups. The definitions for alkyl are as described above.
In another embodiment, the fluorochemical can be an ionic liquid in which an organic cation selected from the group consisting of alkyl pyrroles, alkyl imidazolium, alkyl pyrrolium, alkyl oxazolium, alkyl thiazolium, alkyl pyridinium, alkyl pyrimidinium, alkyl pyridazinium, alkyl pyrazinium, pyrrolidinium, alkyl phosphonium, alkyl morpholinium, dialkyl imidazolium, and alkyl piperidinium is ionically bound to a fluorine anion selected from the group consisting of fluorophosphates, fluoroalkyl-fluorophosphates, fluoroborates, and fluoroalkyl-fluoroborates.
In the silicon nitride film etching solution, the fluorine-containing compound provided in the form of an ionic liquid has advantages of a high boiling point and a decomposition temperature, and there is little concern that the composition of the etching solution may be changed by the decomposition of the fluorine-containing compound in the etching step performed at a high temperature, as compared with hydrogen fluoride or ammonium fluoride which is generally used as a fluorine-containing compound.
According to another embodiment of the present invention, there is provided a method for manufacturing a semiconductor device using the above silicon nitride film etching solution.
According to the preparation method, at least a silicon nitride film (Si) is containedxNy) The silicon substrate of (1) can be subjected to a selective etching step for a silicon nitride film by using the above etching solution, thereby producing a semiconductor device.
Silicon substrates used in the fabrication of semiconductor devices may comprise silicon nitride films (Si)xNy) Or may contain both a silicon oxide film and a silicon nitride film. In the case of a silicon substrate including both a silicon oxide film and a silicon nitride film, the silicon substrate may be in a form in which the silicon oxide film and the silicon nitride film are alternately stacked or in a form in which they are stacked in different regions.
The method for manufacturing a semiconductor device according to the present invention can be applied to a manufacturing process of a computer flash memory device (NAND) device. More specifically, in the process steps required to selectively remove the silicon oxide film without losing the silicon nitride film in the stacked structure body for forming the computer flash memory device, it can be performed by using the above-described etching solution.
As an example, fig. 1 is a schematic cross-sectional view for explaining a silicon nitride film removal process using the etching solution according to the present invention.
Referring to fig. 1, after a mask pattern layer is formed on a laminated structure layer 20 in which silicon nitride films 11 and silicon oxide films 12 are alternately laminated on a silicon substrate 10, a trench 50 is formed by an anisotropic etching process.
Further, referring to fig. 1, the silicon nitride film 11 is etched by supplying the etching solution of the present invention through the region of the trench 50 formed in the laminated structure 20, while leaving only the silicon oxide film 12 and the mask pattern layer 30.
That is, the present invention minimizes the etching of the silicon oxide film 12 in the laminated structure body 20 by using an etching solution whose etching selectivity ratio with respect to the silicon oxide film to the silicon nitride film is improved, and can completely and selectively remove the silicon nitride film 11 in a sufficient time. Thereafter, the semiconductor device is prepared by a subsequent process including a step of forming a gate electrode in a region where the silicon nitride film 11 is removed.
Specific examples of the present invention are given below. However, the following examples are only for specifically illustrating or explaining the present invention, and the present invention is not limited thereto.
Examples
Preparation of etching solutions
Preparation example 1
0.1g equivalent of Tetraethyl Orthosilicate (TEOS), 10ml of water, 100ml of ethanol and 1ml of ammonium hydroxide (NH)4OH) stirring (tumbling) for 30 minutes, and then left for about 1 hour. The procedure of stirring and leaving the above mixture was repeated 20 times to prepare silica. The surface area of the prepared silica and the spherical colloidal dioxide were measured according to the specific surface area detection method (BET method)Surface area of silicon (manufacturer, Inc.; Youngilchem, brand: YGS). The surface area of the prepared silica was 123% with respect to the surface area of spherical colloidal silica (product of manufacturers, Inc.: YGS) based on the same volume.
Preparation example 2
The same composition as in preparation example 1 was left at ordinary temperature for 3 days to prepare silica. The surface area of the prepared silica and the surface area of spherical colloidal silica (product name: YGS, manufactured by Youngilchem Co., Ltd.) were measured according to a specific surface area measurement method. The surface area of the prepared silica was 115% with respect to the surface area of spherical colloidal silica (product of manufacturers, Inc.: YGS) based on the same volume.
Preparation example 3
The same composition as in preparation example 1 was stirred at about 300RPM for 2 hours and then left for about 30 minutes. The procedure of stirring and leaving the above mixture was repeated 20 times to prepare a silicon additive. The surface area of the prepared silica and the surface area of spherical colloidal silica (product name: YGS, manufactured by Youngilchem Co., Ltd.) were measured according to a specific surface area measurement method. The surface area of the prepared silica was 109% based on the same volume relative to the surface area of spherical colloidal silica (product of manufacturer, Inc.: YGS).
Preparation example 4
The same composition as in preparation example 1 was stirred (stabbing) at about 300RPM for 24 hours to prepare a silicon additive. The surface area of the prepared silica and the surface area of spherical colloidal silica (product name: YGS, manufactured by Youngilchem Co., Ltd.) were measured according to a specific surface area measurement method. The surface area of the prepared silica was 102% based on the same volume relative to the surface area of spherical colloidal silica (product name: YGS).
Example 1
A silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 70ppm of the silica of preparation example 1, 30ppm of spherical colloidal silica (product name: YGS) and the remaining amount of water.
Example 2
A silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 90ppm of the silica of preparation example 2, 10ppm of spherical colloidal silica (product name: YGS) and the remaining amount of water.
Example 3
A silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 70ppm of the silica of preparation example 3, 30ppm of spherical colloidal silica (product name: YGS) and the remaining amount of water.
Example 4
A silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 50ppm of the silica of preparation example 4, 50ppm of spherical colloidal silica (product of manufacturer, Youngilchem, brand name: YGS) and the remaining amount of water.
Comparative example 1
The silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 100ppm of spherical colloidal silica (manufacturer, yungilchem, trade name: YGS), and the remaining amount of water.
Comparative example 2
A silicon nitride film etching solution was prepared by mixing 85 weight percent of phosphoric acid, 10ppm of the silica of preparation example 4, 90ppm of spherical colloidal silica (product name: YGS) and the remaining amount of water.
Examples of the experiments
For the silicon nitride film etching solutions having each combination of example 1 to example 4 and comparative example 1 to comparative example 2, the thickness was set to 175 deg.c
The thermal oxide film (thermal oxide layer) and the silicon nitride film of (2) were immersed in a heated etching solution and etched for 10 minutes.
The thicknesses of the silicon oxide film and the silicon nitride film before and after etching were measured using an ellipsometer (Nano-scale Nano-View, model SE MG-1000; Ellipsometric), and the etching rates were calculated by dividing the difference in the thicknesses of the silicon oxide film and the silicon nitride film before and after etching by the time (10 minutes).
The measured etching rates are shown in table 1 below.
TABLE 1
As shown in table 1 above, the silicon nitride film etching solutions of examples 1 to 4 can reduce the etching rate of the silicon oxide film as compared with the silicon nitride film etching solutions of comparative examples 1 to 2, and thus can improve the etching selectivity of the silicon nitride film with respect to the silicon oxide film.
While the embodiments of the present invention have been described above, those skilled in the art can make various modifications and changes to the present invention by adding, changing, deleting or adding components without departing from the scope of the invention described in the claims of the present invention, and these are intended to be included in the claims of the present invention.
Claims (8)
1. A silicon nitride film etching solution characterized in that,
comprises the following steps:
phosphoric acid aqueous solution; and
an additive for silicon, which is a silicon-containing additive,
the silicon additive comprises spherical first colloidal silica and second colloidal silica particles,
the surface area of the second colloidal silica particles is more than 100% and not more than 124% with respect to the surface area of the spherical first colloidal silica particles on the basis of the same volume,
the content of the second colloidal silica particles contained in the silicon additive is 50% or more.
2. The silicon nitride film etching solution according to claim 1, wherein the surface area of the second colloidal silica particles is 110% to 124% of the surface area of the spherical first colloidal silica particles on the basis of the same volume.
3. The silicon nitride film etching solution according to claim 1, wherein said silicon nitride film etching solution contains 100ppm to 100000ppm of said silicon additive.
4. The silicon nitride film etching solution according to claim 1, further comprising at least one fluorine-containing compound selected from the group consisting of hydrogen fluoride, ammonium bifluoride and ammonium bifluoride.
5. The silicon nitride film etching solution according to claim 1, further comprising a fluorine-containing compound having an organic cation and a fluorine anion in an ion-bonded form.
6. The silicon nitride film etching solution according to claim 5, wherein the organic cation is at least one selected from the group consisting of alkylimidazolium, dialkylimidazolium, alkylpyridinium, alkylpyrrolidinium, alkylphosphonium, alkylmorpholinium, and alkylpiperidinium.
7. The silicon nitride film etching solution according to claim 5, wherein the fluorine-based anion is at least one selected from the group consisting of fluorophosphates, fluoroalkyl-fluorophosphates, fluoroborates, and fluoroalkyl-fluoroborates.
8. A method for manufacturing a semiconductor device, comprising performing an etching process by using the silicon nitride film etching solution according to claim 1.
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| Application Number | Priority Date | Filing Date | Title |
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| KR1020190082502A KR20210006641A (en) | 2019-07-09 | 2019-07-09 | Etching solution for silicon nitride layer and method for preparing semiconductor device using the same |
| KR10-2019-0082502 | 2019-07-09 |
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| CN112216607A true CN112216607A (en) | 2021-01-12 |
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| CN116023946A (en) * | 2022-12-28 | 2023-04-28 | 浙江奥首材料科技有限公司 | Silicon nitride mask layer etching solution, preparation method, application and etching method |
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- 2019-07-09 KR KR1020190082502A patent/KR20210006641A/en not_active Application Discontinuation
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116023946A (en) * | 2022-12-28 | 2023-04-28 | 浙江奥首材料科技有限公司 | Silicon nitride mask layer etching solution, preparation method, application and etching method |
| CN116023946B (en) * | 2022-12-28 | 2024-06-07 | 浙江奥首材料科技有限公司 | Silicon nitride mask layer etching solution, preparation method, application and etching method |
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| KR20210006641A (en) | 2021-01-19 |
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