WO2014091817A1 - 基板洗浄液および基板洗浄方法 - Google Patents
基板洗浄液および基板洗浄方法 Download PDFInfo
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- WO2014091817A1 WO2014091817A1 PCT/JP2013/077468 JP2013077468W WO2014091817A1 WO 2014091817 A1 WO2014091817 A1 WO 2014091817A1 JP 2013077468 W JP2013077468 W JP 2013077468W WO 2014091817 A1 WO2014091817 A1 WO 2014091817A1
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- substrate
- solution
- cleaning
- concentration
- sulfuric acid
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- 238000004140 cleaning Methods 0.000 title claims abstract description 111
- 239000000758 substrate Substances 0.000 title claims abstract description 110
- 238000000034 method Methods 0.000 title claims description 22
- 239000012530 fluid Substances 0.000 title abstract 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 190
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims abstract description 136
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims abstract description 68
- 229910052581 Si3N4 Inorganic materials 0.000 claims abstract description 47
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims abstract description 47
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 43
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 43
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 21
- 238000009835 boiling Methods 0.000 claims abstract description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims description 78
- 150000004968 peroxymonosulfuric acids Chemical class 0.000 claims description 58
- 238000005530 etching Methods 0.000 abstract description 78
- 239000004065 semiconductor Substances 0.000 abstract description 37
- JRKICGRDRMAZLK-UHFFFAOYSA-L peroxydisulfate Chemical compound [O-]S(=O)(=O)OOS([O-])(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 abstract description 5
- 230000010354 integration Effects 0.000 abstract description 2
- 239000000243 solution Substances 0.000 description 141
- 238000012546 transfer Methods 0.000 description 44
- 238000003860 storage Methods 0.000 description 41
- 239000011259 mixed solution Substances 0.000 description 32
- 238000002156 mixing Methods 0.000 description 20
- 238000012360 testing method Methods 0.000 description 16
- 229910004298 SiO 2 Inorganic materials 0.000 description 14
- 238000010438 heat treatment Methods 0.000 description 12
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 238000005406 washing Methods 0.000 description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 3
- 239000007800 oxidant agent Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000004448 titration Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- 208000035404 Autolysis Diseases 0.000 description 1
- 206010057248 Cell death Diseases 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 1
- 239000012935 ammoniumperoxodisulfate Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- JRKICGRDRMAZLK-UHFFFAOYSA-N peroxydisulfuric acid Chemical compound OS(=O)(=O)OOS(O)(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-N 0.000 description 1
- YXJYBPXSEKMEEJ-UHFFFAOYSA-N phosphoric acid;sulfuric acid Chemical compound OP(O)(O)=O.OS(O)(=O)=O YXJYBPXSEKMEEJ-UHFFFAOYSA-N 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000012286 potassium permanganate Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000028043 self proteolysis Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- DAFQZPUISLXFBF-UHFFFAOYSA-N tetraoxathiolane 5,5-dioxide Chemical compound O=S1(=O)OOOO1 DAFQZPUISLXFBF-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
- C11D7/02—Inorganic compounds
- C11D7/04—Water-soluble compounds
- C11D7/08—Acids
-
- 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
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31105—Etching inorganic layers
- H01L21/31111—Etching inorganic layers by chemical means
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
- C11D2111/10—Objects to be cleaned
- C11D2111/14—Hard surfaces
- C11D2111/22—Electronic devices, e.g. PCBs or semiconductors
Definitions
- the present invention relates to the manufacture of electronic components, and to a substrate cleaning solution and a substrate cleaning method for etching silicon nitride while suppressing etching of silicon oxide on a substrate having silicon oxide and silicon nitride.
- silicon nitride is used as a silicon oxide film-forming hard mask, a sidewall for protecting a fine pattern, a CMP polishing stopper, and the like.
- a CMP polishing stopper As the degree of integration of semiconductors increases, the structure becomes finer and the film structure becomes thinner, and the thickness of the silicon oxide film is also decreasing.
- Etching is performed to pattern silicon nitride by etching. Conventionally, a phosphoric acid solution at about 160 ° C. has been used for etching the silicon nitride film (for example, Patent Document 1).
- Patent Document 2 proposes an etching solution containing sulfuric acid and fluoride as main components and containing 5% by mass or less of water.
- Patent Document 3 proposes an etching solution containing phosphoric acid, sulfuric acid, and an oxidizing agent that does not contain a metal element, and ammonium peroxodisulfate is exemplified as the oxidizing agent.
- the present invention has been made against the background of the above circumstances, and provides a substrate cleaning solution and a substrate cleaning method capable of obtaining a high silicon nitride etching rate and suppressing a silicon oxide etching to obtain a high selectivity. For the purpose.
- the first present invention has silicon nitride and silicon oxide on the same substrate, and at least a part of one or both of the silicon nitride and the silicon oxide is exposed.
- a cleaning solution used for cleaning a substrate which includes electrolytic sulfuric acid and water containing persulfuric acid generated by electrolysis of phosphoric acid and sulfuric acid, and is heated to 165 ° C. or more and below the boiling point and used for the cleaning. It is characterized by.
- the substrate cleaning method according to the second aspect of the present invention is characterized in that, in the first aspect of the present invention, the persulfuric acid generated by electrolysis is 1.0 to 8.0 g / L in the concentration of the entire cleaning liquid. To do.
- the substrate cleaning liquid according to the third aspect of the present invention is the substrate cleaning liquid according to the first or second aspect of the present invention, wherein the phosphoric acid concentration is 15 to 40% by mass and the sulfuric acid concentration is 30 to 85% by mass in the entire cleaning liquid. %.
- the mass% concentration of the phosphoric acid and the mass% concentration of the sulfuric acid are 1: 1 in the entire cleaning liquid. .. in the range of 5 to 1: 4.
- the substrate cleaning liquid of the fifth aspect of the present invention is characterized in that, in any of the first to fourth aspects of the present invention, the moisture content is 15 to 25% by mass.
- the substrate cleaning solution of the sixth aspect of the present invention is characterized in that, in any of the first to fifth aspects of the present invention, the substrate cleaning liquid is used for single wafer cleaning of the substrate.
- a substrate cleaning method is the method for cleaning a substrate having silicon nitride and silicon oxide on the same substrate, wherein at least a part of one or both of the silicon nitride and the silicon oxide is exposed.
- the substrate is brought into contact with the substrate cleaning liquids of the first to sixth aspects of the present invention, and silicon nitride on the substrate is selectively etched.
- the substrate cleaning method of the eighth aspect of the present invention is characterized in that, in the seventh aspect of the present invention, the silicon nitride is laminated on the silicon oxide in the substrate.
- the substrate cleaning method of the ninth aspect of the present invention is characterized in that, in the seventh or eighth aspect of the present invention, the substrate has a pattern line width of 32 nm or less.
- a substrate cleaning method is characterized in that, in any of the seventh to ninth aspects of the present invention, the substrate is cleaned in a single-wafer manner with the cleaning liquid.
- the substrate cleaning method according to an eleventh aspect of the present invention is the substrate cleaning method according to any one of the seventh to tenth aspects of the present invention, wherein the cleaning liquid used for cleaning is recovered and subjected to electrolysis to increase the concentration of persulfuric acid. It is used for washing.
- regulated by this invention is demonstrated.
- generated by electrolyzing a sulfuric acid is included, and a persulfate is not included.
- the etching property of silicon nitride by phosphoric acid can be obtained satisfactorily.
- phosphoric acid has an action of etching silicon oxide, the etching of silicon oxide by phosphoric acid is suppressed by sulfuric acid and persulfuric acid.
- Persulfuric acid concentration 1.0 g / L to 8.0 g / L
- Etching of silicon oxide by phosphoric acid is suppressed by the strong oxidizing power of persulfuric acid (which is a generic term for peroxomonosulfuric acid and peroxodisulfuric acid).
- persulfuric acid which is a generic term for peroxomonosulfuric acid and peroxodisulfuric acid.
- Conventionally proposed persulfate has a lower degree of dissociation than persulfuric acid and needs to be added in an increased amount.
- precipitates derived from counter ions may adhere to the substrate. Therefore, it is essential that persulfuric acid is not derived from a salt, but is produced by electrolysis of sulfuric acid or is mainly composed thereof.
- the concentration of persulfuric acid is not limited to a specific range, but the concentration of persulfuric acid is preferably in the range of 1.0 to 8.0 g / L in the entire cleaning solution.
- the selection ratio can be further increased. If it is less than 1.0 g / L, the etching suppression action of silicon oxide by phosphoric acid is not sufficient, and even if it exceeds 8.0 g / L, the etching suppression action of silicon oxide is not greatly improved. For the same reason, it is more desirable to set the lower limit to 2.0 g / L and the upper limit to 6.0 g / L.
- persulfuric acid generated by electrolysis of sulfuric acid persulfuric acid generated by mixing sulfuric acid and hydrogen peroxide or mixing sulfuric acid and ozone may be replenished.
- the cleaning liquid desirably has a temperature of 165 ° C. or higher and lower than the boiling point in order to obtain a sufficient etching action of silicon nitride.
- the temperature of the cleaning solution is low, the etching action of silicon nitride by phosphoric acid cannot be obtained sufficiently.
- the etching of the silicon oxide is not promoted even if the cleaning liquid is heated to 165 ° C. or higher, and rather, the suppressing action becomes stronger and a high selection ratio is obtained.
- the cleaning liquid temperature is more preferably 170 ° C. or higher, and more preferably 175 ° C. or higher for the same reason.
- the temperature of the cleaning liquid is preferably less than the boiling point.
- Phosphoric acid concentration 15-40% by mass
- Sulfuric acid concentration 30-85% by mass
- the lower limit of the phosphoric acid concentration is more preferably 24% by mass, and the upper limit is more preferably 40% by mass.
- the sulfuric acid concentration is less than 30% by mass, the etching suppression is insufficient, the SiO 2 etching rate is large, and the practicality is low.
- the sulfuric acid concentration exceeds 85% by mass, the SiN etching rate becomes small and the practicality is low. Therefore, the sulfuric acid concentration is desirably 30 to 85% by mass.
- the lower limit of the sulfuric acid concentration is more preferably 50% by mass, and the upper limit is more preferably 70% by mass.
- the phosphoric acid concentration and the sulfuric acid concentration are shown as concentrations with respect to the entire cleaning liquid.
- Concentration ratio of phosphoric acid and sulfuric acid 1: 1.5 to 1: 4 (mass% concentration ratio)
- concentration ratio is less than 1: 1.5, that is, when the concentration of sulfuric acid is relatively low, the etching suppression is insufficient, the SiO 2 etching rate is increased, and the practicality is low.
- concentration ratio exceeds 1: 4
- the action of phosphoric acid is excessively suppressed, the SiN etching rate becomes small, and the practicality is low.
- the concentration ratio of phosphoric acid and sulfuric acid is preferably 1: 1.5 to 1: 4. Furthermore, the concentration ratio of phosphoric acid and sulfuric acid is more preferably 1: 2 for the lower limit and 1: 3 for the upper limit. Further, it is particularly desirable that the above-mentioned concentration ratio of phosphoric acid and sulfuric acid satisfies the above range in an appropriate range of the phosphoric acid concentration and the sulfuric acid concentration.
- Moisture content 15-25% by mass
- the hydrogen ion concentration decreases, so the SiN etching rate based on the following reaction formula decreases.
- the moisture content exceeds 25% by mass, the boiling point is lowered and high temperature treatment cannot be performed, and the SiN etching rate is lowered.
- the water content is preferably in the range of 15 to 25% by mass.
- a substrate having silicon nitride and silicon oxide on the same substrate and at least a part of which is exposed is a target to be cleaned.
- the type or the like of the substrate is not particularly limited in the present invention, and the form in which silicon nitride and silicon oxide exist is not limited to a specific one.
- Silicon nitride and silicon oxide may be obtained by stacking silicon nitride on silicon oxide. In that case, the etching of silicon oxide becomes a problem from the time when the silicon nitride is etched first and the silicon oxide is exposed from the silicon nitride, and it is necessary to suppress the etching of the silicon oxide.
- a highly integrated semiconductor substrate formed on a substrate or having a formed pattern line width of 32 nm or less is a particularly suitable cleaning target.
- a substrate having such a fine line width is cleaned with a conventional cleaning liquid, a portion corresponding to the fine line width is likely to be damaged if a sufficient cleaning effect is to be obtained.
- the pattern line width of the substrate to be cleaned is not limited to a specific one.
- the cleaning method using the cleaning liquid of the present invention can also be cleaned in a batch system in which the substrate is immersed in the cleaning liquid.
- a single wafer type is suitable. Batch cleaning has a problem of reattachment of particles, and single wafer processing is more suitable for removing metal residues.
- the present invention it is possible to effectively etch silicon nitride while suppressing the etching of silicon oxide, and to increase the selection ratio. Cleaning can be performed. In particular, even a substrate with a fine pattern line width can be cleaned without hindrance.
- Embodiment 1 Hereinafter, an embodiment of the present invention will be described. Since the part that performs the etching reaction generally uses a cleaning device (cleaning machine), the part that performs the etching reaction in this embodiment is also referred to as a cleaning machine. A semiconductor substrate cleaning system 1a having a cleaning machine will be described below with reference to FIG.
- the semiconductor substrate cleaning system 1a includes a cleaning machine 2 corresponding to a cleaning unit, a first solution storage tank 4 for storing an electrolytic sulfuric acid solution containing persulfuric acid generated by electrolysis of sulfuric acid, and a second solution for storing a phosphoric acid solution. And a storage tank 10.
- the electrolytic sulfuric acid solution containing persulfuric acid corresponds to the first solution
- the phosphoric acid solution corresponds to the second solution.
- the washing machine 2 may be either a single wafer washing machine or a batch washing machine, but a single wafer washing machine that can always be treated with a clean liquid is more preferable.
- the cleaning machine 2 includes a delivery unit 30 that delivers a cleaning solution to the semiconductor substrate 100.
- the delivery unit 30 supplies the cleaning solution to the semiconductor substrate 100 by spraying, dripping, flowing down, or in the case of a batch type cleaning machine. Note that the solution may be sprayed onto the semiconductor substrate 100 by applying pressure when dropping or flowing.
- the first solution storage tank 4 is connected to a first solution transfer path 5 for transferring the solution in the first solution storage tank 4.
- the second solution storage tank 10 is connected to a second solution transfer path 11 that transfers the solution in the second solution storage tank 10.
- a liquid feed pump 6 is provided in the first solution transfer path 5, and a liquid feed pump 12 is provided in the second solution transfer path 11.
- the first solution transfer path 5 and the second solution transfer path 11 merge at the downstream side of the liquid feed pump 6 and the liquid feed pump 12 to transfer a mixed solution in which the first solution and the second solution are mixed.
- the transfer path 20 is configured, and the downstream end of the common transfer path 20 is connected to the delivery unit 30.
- the common transfer path 20 is provided with a heater 7 for heating the mixed solution to be sent.
- the first solution storage tank 4 sulfuric acid adjusted so that the concentration of persulfuric acid in the mixed solution is a predetermined concentration of 1.0 to 8.0 g / L and the sulfuric acid concentration is a predetermined concentration of 30 to 85 mass%.
- the electrolytic sulfuric acid solution that is the first solution may be supplied to the first solution storage tank 4 and stored in a batch manner, and an electrolytic sulfuric acid solution containing a required amount of persulfuric acid corresponding to the consumption amount may be continuously added. It may be replenished.
- the electrolytic sulfuric acid solution can be efficiently generated and supplemented by electrolysis of sulfuric acid.
- the phosphoric acid concentration in the mixed solution is adjusted to a predetermined concentration of 15 to 40% by mass.
- the semiconductor substrate 100 When cleaning the semiconductor substrate 100, the semiconductor substrate 100 is placed on and supported by a semiconductor support, and the sulfuric acid solution containing persulfuric acid in the first solution storage tank 4 is transferred to the first solution by the liquid feed pump 6. Liquid is fed through the passage 5 at a predetermined flow rate, and the phosphoric acid solution in the second solution storage tank 10 is fed at a predetermined flow rate through the second solution transfer passage 11 by the liquid feed pump 12. Both liquids are mixed in a common transfer path 20 where both transfer paths meet. Note that the flow rate of the sulfuric acid solution and the flow rate of the phosphoric acid solution are set so that a predetermined mixing ratio is obtained when the two solutions are mixed and the flow rate of the mixed solution is a predetermined amount.
- the mixed solution of the electrolytic sulfuric acid solution containing persulfuric acid and phosphoric acid is heated in a transient manner by the heater 7 after joining.
- the heating temperature is adjusted so that the liquid temperature becomes a predetermined temperature of 165 ° C. or higher (less than the boiling point) when contacting the semiconductor substrate 100.
- heating is performed by the common transfer path 20, but heaters may be provided in both the first solution transfer path 5 and the second solution transfer path 11 to heat each solution.
- heating in each transfer path and heating in the common transfer path may be used in combination. In any case, it is desirable to adjust the liquid temperature on the semiconductor 100 so that the liquid temperature becomes a predetermined temperature of 165 ° C. or higher (below the boiling point).
- the sulfuric acid solution containing persulfuric acid and the phosphoric acid solution had a persulfuric acid concentration of 1.0 to 8.0 g / L, a phosphoric acid concentration of 15 to 40% by mass, and a sulfuric acid concentration of 30 to 85%. %, Moisture content of 15% by mass to 25% by mass, liquid temperature of 165 ° C. or higher (less than boiling point), and sent from the delivery unit 30 to contact the semiconductor substrate 100, and the semiconductor substrate 100 is etched.
- the concentration adjustment and the water content adjustment of the sulfuric acid solution and the phosphoric acid solution may be mixed with water in the first solution storage tank 4 to a predetermined concentration, or the sulfuric acid solution having a predetermined concentration may be adjusted to the first solution storage tank 4.
- the phosphoric acid solution may be mixed with water in the second solution storage tank 10, or a phosphoric acid solution having a predetermined concentration may be supplied to the second solution storage tank 10.
- the sulfuric acid solution containing persulfuric acid and the phosphoric acid solution had a persulfuric acid concentration of 1.0 to 8.0 g / L, a phosphoric acid concentration of 15 to 40% by mass, and a sulfuric acid concentration of 30 to 85%. %, Water content of 15% by mass to 25% by mass, liquid temperature of 165 ° C. or higher (below boiling point), it may be delivered from the delivery unit 30 in a mixed state or mixed on the semiconductor substrate 100 to adjust the solution.
- the method and the etching method are not limited to this form.
- the semiconductor substrate cleaning system 1b includes a single wafer cleaning machine 2 corresponding to an etching unit, a first solution storage tank 4 for storing an electrolytic sulfuric acid solution containing persulfuric acid generated by electrolysis, and a second storage for storing a phosphoric acid solution.
- the solution storage tank 10 is provided.
- a heater 8 is provided in the first solution storage tank, and a heater 9 is provided in the second solution storage tank.
- the temperature on the first solution storage tank 4 side where the electrolytic sulfuric acid solution containing persulfuric acid is stored is preferably set to a temperature at which the reaction rate of self-decomposition of persulfuric acid is relatively small, for example, 50 to 100 ° C.
- the concentration of persulfuric acid is a predetermined concentration of 1.0 to 8.0 g / L, and the sulfuric acid concentration is A sulfuric acid solution adjusted to have a predetermined concentration of 30 to 98% by mass is accommodated.
- the second solution storage tank 10 is adjusted so that the phosphoric acid concentration is 15 to 40% by mass in the mixed solution obtained by mixing with the electrolytic sulfuric acid solution containing persulfuric acid as in the first embodiment.
- the electrolytic sulfuric acid solution which is the first solution, may be supplied to the first solution storage tank 4 and stored in a batch manner, and an electrolytic sulfuric acid solution containing a necessary amount of persulfuric acid corresponding to the consumption amount is continuously added. It may be replenished.
- the electrolytic sulfuric acid solution can be efficiently generated and replenished by electrolysis of the sulfuric acid solution.
- the liquid mixture of the first solution (electrolytic sulfuric acid solution) and the second solution (phosphoric acid) is temporarily heated by the heater 7 and the liquid temperature when contacting the semiconductor substrate 100 is 165 ° C. or higher.
- the temperature is raised to a predetermined temperature (below the boiling point).
- the heaters 8 and 9 are heated, the heating burden of the heater 7 can be reduced.
- the semiconductor substrate 100 When etching the semiconductor substrate 100, the semiconductor substrate 100 is supported by the semiconductor support, and a sulfuric acid solution containing persulfuric acid in the first solution storage tank 4 is flowed through the first solution transfer path 5 by the liquid feed pump 6. Then, the phosphoric acid solution in the second solution storage tank 10 is fed by the liquid feed pump 12 through the second solution transfer path 11 at a predetermined flow rate. Both liquids are mixed in a common transfer path 20 where both transfer paths meet. Note that the flow rate of the sulfuric acid solution and the flow rate of the phosphoric acid solution are set so that a predetermined concentration ratio is obtained when the two solutions are mixed, and the flow rate of the mixed solution is a predetermined flow rate.
- the sulfuric acid solution containing persulfuric acid is heated by the heater 8 in the first solution storage tank 4 and the phosphoric acid solution is heated by the heater 9 in the second solution storage tank 10 to be brought into contact with the semiconductor substrate 100
- the liquid temperature is adjusted to a predetermined temperature of 165 ° C. or higher (less than the boiling point).
- the concentration of persulfuric acid is 1.0 to 8.0 g / L
- the concentration of phosphoric acid is 15 to 40% by mass
- the concentration of sulfuric acid is 30 to 85% by mass
- the liquid temperature is 165 ° C. or higher (below the boiling point)
- Embodiment 3 Next, a semiconductor substrate cleaning system 1c according to Embodiment 3 will be described with reference to FIG.
- symbol is attached
- the first solution transfer path 5 connected to the first solution storage tank 4 and the second solution transfer path 11 connected to the second solution storage tank 10 are connected to the mixing tank 25, and the mixing tank
- the common transfer path 20 connected to 25 is connected to the sending unit 30.
- a mixing tank heater 26 is provided in the mixing tank 25, and a heater 7 is provided in the common transfer path 20.
- the first solution is such that the phosphoric acid and sulfuric acid of the mixed solution of the first solution (electrolytic sulfuric acid solution) and the second solution (phosphoric acid solution) stored in the mixing tank 25 have a predetermined concentration ratio.
- the first solution (electrolytic sulfuric acid solution) is transferred from the solution storage tank 4 to the mixing tank 25 through the first solution transfer path 5 by the liquid feed pump 6, and the second solution is transferred from the second solution storage tank 10 by the liquid feed pump 12.
- the second solution (phosphoric acid solution) is transferred to the mixing tank 25 through the path 11.
- the solution in the mixing tank 25 has a predetermined concentration of a persulfuric acid concentration of 1.0 to 8.0 g / L, a sulfuric acid concentration of 30 to 85% by mass, and a phosphoric acid concentration of 15 to 40% by mass.
- the water content is adjusted to 15 to 25% by mass.
- the electrolytic sulfuric acid solution that is the first solution may be supplied to the first solution storage tank 4 and stored in a batch manner, and an electrolytic sulfuric acid solution containing a required amount of persulfuric acid corresponding to the consumption amount may be continuously added. It may be replenished.
- the electrolytic sulfuric acid solution can be efficiently generated and supplemented by electrolysis of the sulfuric acid solution.
- the mixed solution stored in the mixing tank 25 is heated by the mixing tank heater 26 as necessary, and is transferred through the common transfer path 20 by the liquid feeding pump 23. At this time, the mixed solution is heated transiently by the heater 7, and the temperature is raised so that the liquid temperature when contacting the semiconductor substrate 100 becomes a predetermined temperature of 165 ° C. or higher (below the boiling point). If it is heated by the heater 26 at this time, the heating burden of the heater 7 can be reduced. However, when the mixed solution containing persulfuric acid is heated in the mixing tank 25, it is desirable to suppress the temperature to 100 ° C. or less so that the self-decomposition of persulfuric acid does not proceed excessively.
- the semiconductor substrate 100 is etched by the mixed solution coming into contact with the semiconductor substrate 100.
- Embodiment 4 A semiconductor substrate cleaning system 1d according to Embodiment 4 will be described with reference to FIG.
- symbol is attached
- a cleaning machine 2 corresponding to an etching unit, and a recovered liquid storage tank 40 for recovering and reusing a mixed solution of an electrolytic sulfuric acid solution and a phosphoric acid solution used for etching that comes out of the cleaning machine 2.
- a transfer path 41 is connected between the cleaning machine 2 and the recovered liquid storage tank 40, a transfer path 42 is connected to the recovered liquid storage tank 40, and a liquid feed pump 43 is provided in the transfer path 42. ing.
- the electrolyzer 50 is connected to the end of the transfer path 42 on the downstream side of the liquid feed pump 43.
- the drain side of the electrolyzer 50 and the washing machine 2 are connected by a transfer path 51, and the downstream end of the transfer path 51 is connected to the delivery unit 30.
- the transfer path 51 is provided with a heater 7 for heating the mixed solution to be sent.
- the liquid mixture collected in the recovered liquid storage tank 40 is sent to the electrolysis apparatus 50 through the transfer path 42 by the liquid feed pump 43.
- the collected mixed solution is electrolyzed under a predetermined condition to obtain a mixed solution having a predetermined concentration and temperature of phosphoric acid sulfuric acid containing perphosphoric acid and persulfuric acid adjusted to a predetermined concentration, and the transfer path 51.
- the heater 7 is heated in a transient manner. The heating temperature is adjusted so that the liquid temperature becomes a predetermined temperature of 165 ° C. or higher (less than the boiling point) when contacting the semiconductor substrate 100.
- the mixed solution is adjusted to have a phosphoric acid concentration of 15 to 40% by mass, a sulfuric acid concentration of 30 to 85% by mass, and a moisture content of 15 to 25% by mass.
- the electrolysis conditions are adjusted so that the concentration in the mixed solution of persulfuric acid becomes a predetermined concentration of 1.0 to 8.0 g / L.
- the mixed solution containing the electrolytic sulfuric acid is heated to a predetermined temperature, sent from the sending unit 30, contacts the semiconductor substrate 100, and the semiconductor substrate 100 is etched.
- This equipment collects the liquid mixture used for etching and regenerates and supplies the persulfuric acid reduced by reaction and autolysis by electrolysis of the mixed solution, reducing the amount of chemical used and reducing the amount of waste liquid. It is more preferable because it can be reduced.
- Electrolytic sulfuric acid is generated by electrolyzing a predetermined concentration of sulfuric acid.
- Phosphoric acid: sulfuric acid 1: 2 (wt% concentration ratio) while adjusting to a predetermined moisture concentration by mixing 500 mL of phosphoric acid of a predetermined concentration and 1000 mL of electrolytic sulfuric acid containing sulfuric acid having the same mass% concentration as phosphoric acid. ), A mixed solution having a persulfuric acid concentration of 5 g / L was prepared.
- the oxidizing substance concentration was measured by the iodine titration method, the hydrogen peroxide concentration was analyzed by the potassium permanganate titration method, and the difference between them was calculated as the persulfate concentration. .
- the mixture was heated to 180 ° C. and dropped onto a silicon substrate with exposed SiN for 3 minutes, and subjected to a SiN etching test. Table 1 shows the test conditions.
- the etching rate of silicon nitride was determined by dividing the decrease in film thickness of the silicon substrate with the silicon nitride film by using the ellipsometer manufactured by Mizoji Optical Co., Ltd.
- Table 1 reveals that a moisture concentration (moisture content) of 15 to 25% by mass is preferable and 18 to 22% by mass is more preferable in terms of good etching and high selectivity of silicon nitride. Yes.
- Example 2 The SiN etching test was performed under the same conditions as in Example 1 except that the sulfuric acid electrolysis conditions were changed so that the persulfuric acid concentration of the mixed solution became a predetermined concentration. However, when the persulfuric acid concentration was 0, electrolysis was not performed. The mixture was heated to 180 ° C. and dropped onto a silicon substrate with exposed SiO 2 for 15 minutes, and an SiO 2 etching test was performed. Each etching rate and selection ratio were calculated in the same manner as in Experimental Example 1. Test conditions and test results are shown in Table 2.
- the selection ratio is 170 or more, when the persulfuric acid concentration is 2.0 g / L or more, the selection ratio is 200 or more, and the persulfuric acid concentration is 6.0 g / L or more.
- the ratio was about 250, and even when the persulfuric acid concentration was higher than that, the selectivity ratio was about 250.
- a test in which hydrogen peroxide was added to sulfuric acid was performed assuming SPM as comparison data, and the results are shown in the graph of FIG. As a result of a test simulating SPM (sulfuric acid / hydrogen peroxide), the selectivity did not reach 150 under any of the conditions.
- Example 3 The same conditions as in Comparative Example 3 and Example 1 except that the phosphoric acid concentration, sulfuric acid concentration, water concentration, and liquid temperature were changed for each of cases where the mixed solution did not contain persulfuric acid and when it contained (5 g / L). And SiN etching test. The mixture was heated at a predetermined temperature and dropped on a silicon substrate with exposed SiO 2 for 15 minutes to perform a SiO 2 etching test. Each etching rate and selection ratio were calculated in the same manner as in Experimental Example 1. Test conditions and test results are shown in Table 3.
- Example 4 The SiN etching test was performed under the same conditions as in Example 1 except that the concentration ratio of the mixed solution after mixing phosphoric acid and sulfuric acid was changed. The mixture was heated to 180 ° C. and dropped onto a silicon substrate with exposed SiO 2 for 15 minutes, and an SiO 2 etching test was performed. Each etching rate and selection ratio were calculated in the same manner as in Experimental Example 1. Test conditions and test results are shown in Table 4.
- the selectivity is 170 or more.
- the ratio of the mass% of phosphoric acid to the mass% of sulfuric acid is 1: 5
- the SiN etching rate decreases although the selectivity is high. Accordingly, it was confirmed that the concentration ratio of phosphoric acid and sulfuric acid is preferably 1: 1.5 to 1: 4, and more preferably 1: 2 to 1: 3 for the same reason.
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Abstract
Description
生産性を高め高精度のパターニングを行おうとすると、選択的に酸化シリコンのエッチングを抑制しながら窒化シリコンのエッチングを促進させる必要があり、SiO2及びSiNが露出している基板の洗浄においてはSiO2エッチングを抑えつつSiNを選択的にエッチングすることでSiNのエッチングレートに対するSiO2のエッチングレートの比を示す選択比を高めた改善方法が従来から提案されている(例えば特許文献2、3参照)。
本発明では、硫酸を電解することによって生成される過硫酸を含んでおり、過硫酸塩を含まないものである。
本発明では、リン酸による窒化シリコンのエッチング性が良好に得られる。ただし、リン酸は酸化シリコンをエッチングする作用を有するため、硫酸および過硫酸によってリン酸による酸化シリコンのエッチングを抑制する。これら作用により窒化シリコンを選択的にエッチングして効果的な洗浄を行うことを可能にしている。
以下、さらに各条件等について詳細に説明する。
過硫酸(ペルオキソ一硫酸とペルオキソ二硫酸の総称とする)の強い酸化力によってリン酸による酸化シリコンに対するエッチングが抑制される。従来提案されている過硫酸塩は、過硫酸より解離度が低く添加量を増やす必要がある。またそれに伴い対イオンに由来する析出物が基板に付着するおそれがある。したがって、過硫酸は塩由来のものではなく、硫酸の電解によって生成されたもの、またはこれを主とすることが必須となる。
なお、本発明としては過硫酸の濃度が特定の範囲に限定されるものではないが、過硫酸の濃度が、洗浄液全体において1.0~8.0g/Lの範囲にあるのが望ましい。この範囲設定によって、選択比をより高くすることができる。1.0g/L未満では、リン酸による酸化シリコンのエッチング抑制作用が十分でなく、また、8.0g/Lを超えても、酸化シリコンのエッチング抑制作用がそれ以上大きく改善しない。なお、同様の理由で下限を2.0g/L、上限を6.0g/Lとするのが一層望ましい。
洗浄液は、窒化シリコンのエッチング作用を十分に得るため、洗浄に際し洗浄液が165℃以上、沸点未満の温度を有しているのが望ましい。
洗浄液の温度が低いとリン酸による窒化シリコンのエッチング作用が十分に得られない。なお、硫酸の電解により生成された過硫酸と硫酸とを含むことにより洗浄液を165℃以上としても酸化シリコンのエッチングは助長されず、むしろ抑制作用が強くなり高い選択比が得られる。硫酸の電解により生成された過硫酸と硫酸とを適正に含有していないと、洗浄液の加温によって酸化シリコンのエッチングが加速され、高い選択比が得られない。
上記観点から洗浄液温度は170℃以上がさらに望ましく、同様の理由で175℃以上が一層望ましい。
また、取り扱い上、洗浄液の温度は沸点未満が望ましい。
硫酸濃度 :30~85質量%
リン酸濃度と硫酸濃度とをバランスさせることで、窒化シリコンのエッチング性を高く維持し、かつ酸化シリコンのエッチングを抑制することで、洗浄効果を保ちつつ高い選択比が得られる。
ここで、リン酸濃度が15質量%未満ではSiNエッチングレートが小さく実用性が低くなる。一方、リン酸濃度が40質量%超過ではSiO2エッチングレートが大きくなり、選択比SiN/SiO2は小さくなる。したがって、リン酸濃度は15~40質量%が望ましい。なお、同様の理由でリン酸濃度の下限は24質量%、上限は40質量%が一層望ましい。
また、硫酸濃度は30質量%未満ではエッチング抑制が不十分でSiO2エッチングレートが大きく実用性が低くなる。一方、硫酸濃度が85質量%超過ではSiNエッチングレートが小さくなり実用性が低い。したがって、硫酸濃度は30~85質量%が望ましい。なお、同様の理由で硫酸濃度の下限は50質量%、上限は70質量%が一層望ましい。
なお、上記リン酸濃度、硫酸濃度は、洗浄液全体に対する濃度として示されるものである。
リン酸と硫酸とを混合した混合液中の前記リン酸の質量%濃度と、前記硫酸の質量%濃度とを適正なバランス比とすることで、洗浄効果を保ちつつ高い選択比が得られる。
濃度比が1:1.5未満、すなわち硫酸の濃度が相対的に低くなると、エッチング抑制が不十分でSiO2エッチングレートが大きくなり実用性が低い。一方、濃度比が1:4超過では、リン酸の作用が抑制されすぎてSiNエッチングレートが小さくなり実用性が低い。したがって、リン酸と硫酸の濃度比は、1:1.5~1:4が望ましい。さらには、リン酸と硫酸の濃度比は、下限を1:2、上限を1:3とするのが一層望ましい。
また、上記したリン酸と硫酸の濃度比は、前記リン酸濃度と硫酸濃度の適正な範囲において、上記範囲を満たしているのが特に望ましい。
洗浄液の含水率が15質量%未満になると水素イオン濃度が小さくなるため下記反応式に基づくSiNエッチングレートが小さくなる。また、含水率が25質量%超過だと沸点が下がり高温処理できずSiNエッチングレートが低下する。このため、含水率は15~25質量%の範囲が望ましい。なお、同様の理由で下限を18質量%、上限を22質量%とするのが一層望ましい。
SiN3N4+12H2O+4H+→3Si(OH)4+4NH4 +⇔6H2O+3SiO2+4NH4 +
但し、本発明としては洗浄対象となる基板のパターン線幅が特定のものに限定されるものではない。
以下に、本発明の一実施形態を説明する。
エッチング反応を行う部分は一般的に洗浄を行う装置(洗浄機)を用いるため、本形態の説明もエッチング反応を行う部分は洗浄機と示す。
洗浄機を有する半導体基板洗浄システム1aを図1に基づいて以下に説明する。
洗浄機2は枚葉式洗浄機でもバッチ式洗浄機のどちらでもよいが常に清浄な液で処理ができる枚葉式の方がより望ましい。
第1溶液である電解硫酸溶液は、バッチ式に第1溶液貯留槽4に供給し貯留するものでもよく、また、消費量に相応して必要量の過硫酸を含む電解硫酸溶液を連続的に補充するものであってもよい。電解硫酸溶液は、硫酸の電解によって効率よく生成し、補充することができる。
一方、第2溶液貯留槽10では、混合溶液中のリン酸濃度が15~40質量%の所定濃度となるように調整されている。
硫酸溶液およびリン酸溶液の濃度調整、含水率調整は、第1溶液貯留槽4内で水と混合し所定の濃度にしてもよいし、所定の濃度にした硫酸溶液を第1溶液貯留槽4に供給してもよい。また、リン酸溶液も硫酸溶液同様に第2溶液貯留槽10内で水と混合してもよいし、所定の濃度にしたリン酸溶液を第2溶液貯留槽10に供給してもよい。
過硫酸を含む硫酸溶液とリン酸溶液とは、混合溶液において、過硫酸の濃度が1.0~8.0g/L、リン酸の濃度が15~40質量%、硫酸濃度が30~85質量%、含水率が15質量%~25質量%、液温が165℃以上(沸点未満)の状態で、送出部30から混合状態で送出もしくは半導体基板100上で混合されれば良く、溶液の調整方法、エッチング方法はこの形態に限定しない。
次に、実施形態2の半導体基板洗浄システム1bを図2に基づいて説明する。なお、実施形態1と同様の構成については同一の符号を付しており、その説明を省略または簡素化する。
半導体基板洗浄システム1bは、エッチング部に相当する枚葉式洗浄機2と、電解によって生成された過硫酸を含む電解硫酸溶液を貯留する第1溶液貯留槽4とリン酸溶液を貯留する第2溶液貯留槽10とを備えている。
第1溶液貯留槽にはヒーター8が設けられ、第2溶液貯留槽にはヒーター9が設けられている。過硫酸が含まれる電解硫酸溶液が貯留される第1溶液貯留槽4側の温度は、過硫酸の自己分解の反応速度が比較的小さい温度、例えば50~100℃に設定されるのが望ましい。
第1溶液貯留槽4には、実施形態1と同様にリン酸溶液との混合により得られる混合溶液において、過硫酸の濃度が1.0から8.0g/Lの所定濃度となり、硫酸濃度が30~98質量%の所定濃度となるように調整した硫酸溶液を収容する。一方、第2溶液貯留槽10には、実施形態1と同様に上記過硫酸を含む電解硫酸溶液との混合によって得られる混合溶液においてリン酸濃度が15~40質量%となるように調整する。
第1溶液である電解硫酸溶液は、バッチ式に第1溶液貯留槽4に供給し、貯留するものでもよく、また、消費量に相応して必要量の過硫酸を含む電解硫酸溶液を連続的に補充するものであってもよい。電解硫酸溶液は、硫酸溶液の電解によって効率よく生成し、補充することができる。
また、過硫酸を含む硫酸溶液は、第1溶液貯留槽4内のヒーター8で、リン酸溶液は、第2溶液貯留槽10内のヒーター9で加熱し、半導体基板100に接触させるときに、液温が165℃以上(沸点未満)の所定の温度となるように調整する。
電解硫酸溶液とリン酸溶液との混合溶液において、過硫酸の濃度が1.0~8.0g/L、リン酸の濃度が15~40質量%、硫酸濃度が30~85質量%、含水率が15質量%~25質量%、液温が165℃以上(沸点未満)の状態で、送出部30から送出されて半導体基板100に接触し、半導体基板100のエッチングが行われる。
次に、実施形態3の半導体基板洗浄システム1cを図3に基づいて説明する。なお、実施形態1と同様の構成については同一の符号を付しており、その説明を省略または簡素化する。
この実施形態では、第1溶液貯留槽4に接続された第1溶液移送路5と、第2溶液貯留槽10に接続された第2溶液移送路11とを混合槽25に接続し、混合槽25に接続された共通移送路20を送出部30に接続したものである。混合槽25には混合槽ヒーター26が設けられ、共通移送路20にはヒーター7が設けられている。
この実施形態では、混合槽25に貯留される第1溶液(電解硫酸溶液)と第2溶液(リン酸溶液)との混合液のリン酸と硫酸が所定の濃度比になるように、第1溶液貯留槽4から、送液ポンプ6によって第1溶液移送路5を通して第1溶液(電解硫酸溶液)を混合槽25に移送し、第2溶液貯留槽10から送液ポンプ12によって第2溶液移送路11を通して第2溶液(リン酸溶液)を混合槽25に移送する。
第1溶液である電解硫酸溶液は、バッチ式に第1溶液貯留槽4に供給し貯留するものでもよく、また、消費量に相応して必要量の過硫酸を含む電解硫酸溶液を連続的に補充するものであってもよい。電解硫酸溶液は、硫酸溶液の電解によって効率よく生成し補充することができる。
混合槽25に貯留される混合溶液は、必要に応じて混合槽ヒーター26で加熱し、送液ポンプ23によって共通移送路20を通じて移送する。この際にヒーター7によって混合溶液を一過式に加熱し、半導体基板100に接触させる際の液温が165℃以上(沸点未満)の所定温度になるように昇温する。このときヒーター26で加熱されていれば、ヒーター7の加熱負担を軽減できる。但し、過硫酸が含まれる混合溶液を混合槽25内で加熱する場合、過硫酸の自己分解が進行しすぎないように100℃以下に抑えることが望ましい。混合溶液が半導体基板100と接触することにより半導体基板100のエッチングが行われる。
実施形態4の半導体基板洗浄システム1dを図4に基づいて説明する。なお、実施形態1と同様の構成については同一の符号を付しており、その説明を省略または簡素化する。
この実施形態では、エッチング部に相当する洗浄機2と、洗浄機2から出てくるエッチングに使用した電解硫酸溶液とリン酸溶液との混合液を回収循環再利用するための回収液貯留槽40とを備えている。洗浄機2と回収液貯留槽40との間には移送路41が接続されており、更に回収液貯留槽40には移送路42が接続され、移送路42には送液ポンプ43が設けられている。送液ポンプ43の下流側で移送路42の端部に電解装置50が接続されている。電解装置50の排液側と洗浄機2との間は移送路51で接続されており、移送路51の下流端は送出部30に接続されている。また、移送路51には送液される混合溶液を加熱するヒーター7が設けられている。
所定濃度の硫酸を電解して電解硫酸を生成する。
所定濃度のリン酸500mLと、リン酸と同じ質量%濃度の硫酸を含む電解硫酸1000mLを混合することにより、所定の水分濃度に調整しつつ、リン酸:硫酸=1:2(wt%濃度比)、過硫酸濃度5g/Lの混合液を調製した。なお、混合液中の過硫酸濃度の測定については酸化性物質濃度をヨウ素滴定法で測定し、過酸化水素濃度を過マンガン酸カリウム滴定法で分析し、それらの差分を過硫酸濃度として算出した。
混合液を180℃まで昇温してSiNが露出したシリコン基板に3分間滴下してSiNエッチング試験に供した。試験条件を表1に示す。
なお、窒化シリコンのエッチングレートは窒化シリコン膜のついたシリコン基板の膜厚の減少を溝尻光学工業株式会社製のエリプソメーターを用いエッチング処理前と処理後での膜厚の差をエッチング時間で除して求めた。また、窒化シリコンと酸化シリコンのエッチングの選択比は、窒化シリコンと同様にして求めた酸化シリコンのエッチングレートで窒化シリコンのエッチングレートを除して求めた。結果を表1に示す。
混合液の過硫酸濃度が所定濃度になるように硫酸電解条件を振ったこと以外は実施例1と同じ条件でSiNエッチング試験した。ただし、過硫酸濃度が0の場合は電解を行わなかった。
混合液を180℃まで昇温してSiO2が露出したシリコン基板に15分間滴下してSiO2エッチング試験した。各エッチングレートおよび選択比は実験例1と同様に算出した。
試験条件および試験結果を表2に示す。
一方、比較データとしてSPMを想定して硫酸に過酸化水素を添加した場合の試験も実施し、表2の結果と共に図5のグラフに示した。SPM(硫酸過水)を模した試験の結果は、いずれの条件でも選択比は150にも達しなかった。
混合液に過硫酸を含まない場合と含む場合(5g/L)それぞれについて、リン酸濃度、硫酸濃度、水分濃度、及び液温を変えたこと以外はそれぞれ比較例3、実施例1と同じ条件でSiNエッチング試験した。
混合液を所定温度で昇温してSiO2が露出したシリコン基板に15分間滴下してSiO2エッチング試験した。各エッチングレートおよび選択比は実験例1と同様に算出した。試験条件および試験結果を表3に示す。
一方、過硫酸を含有する混合液では、混合液の温度を高めた場合、窒化シリコンのエッチング作用が向上するが、酸化シリコンのエッチングは抑制されているので、選択比は大幅に向上する。
混合液のリン酸と硫酸の混合後の濃度比を振ったこと以外は実施例1と同じ条件でSiNエッチング試験した。
混合液を180℃まで昇温してSiO2が露出したシリコン基板に15分間滴下してSiO2エッチング試験した。各エッチングレートおよび選択比は実験例1と同様に算出した。試験条件および試験結果を表4に示す。
2 洗浄機
4 第1溶液貯留槽
5 第1溶液移送路
6 送液ポンプ
8 ヒーター
9 ヒーター
10 第2溶液貯留槽
11 第2溶液移送路
12 送液ポンプ
20 共通移送路
23 送液ポンプ
25 混合槽
26 ヒーター
30 送出部
40 回収液貯留槽
41 移送路
42 移送路
43 送液ポンプ
51 移送路
100 半導体基板
Claims (11)
- 同一の基板上に窒化シリコンと酸化シリコンとを有し、前記窒化シリコンおよび前記酸化シリコンの一方または両方の少なくとも一部が露出した基板の洗浄に用いられる洗浄液であって、リン酸、硫酸の電解によって生成された過硫酸を含む電解硫酸および水を含み、165℃以上、沸点未満に加温されて前記洗浄に使用されることを特徴とする基板洗浄液。
- 電解によって生成された前記過硫酸が、洗浄液全体の濃度で、1.0~8.0g/Lであることを特徴とする請求項1記載の基板洗浄液。
- 当該洗浄液全体において、前記リン酸の濃度が15~40質量%、前記硫酸の濃度が30~85質量%であることを特徴とする請求項1または2に記載の基板洗浄液。
- 当該洗浄液全体において、前記リン酸の質量%濃度と、前記硫酸の質量%濃度とが、1:1.5~1:4の範囲内にあることを特徴とする請求項1~3のいずれかに記載の基板洗浄液。
- 含水率が15~25質量%であることを特徴とする請求項1~4のいずれかに記載の基板洗浄液。
- 前記基板の枚葉式洗浄に用いられることを特徴とする請求項1~5のいずれかに記載の基板洗浄液。
- 同一の基板上に窒化シリコンと酸化シリコンとを有し、前記窒化シリコンおよび前記酸化シリコンの一方または両方の少なくとも一部が露出した基板の洗浄方法において、前記基板を、請求項1~6のいずれかに記載の基板洗浄液に接触させ、前記基板上の窒化シリコンを選択的にエッチングすることを特徴とする基板洗浄方法。
- 前記基板は、前記酸化シリコン上に前記窒化シリコンが積層されていることを特徴とする請求項7に記載の基板洗浄方法。
- 前記基板は、32nm以下のパターン線幅を有することを特徴とする請求項7または8に記載の基板洗浄方法。
- 前記洗浄液によって前記基板を枚葉式に洗浄することを特徴とする請求項7~9のいずれかに記載の基板洗浄方法。
- 洗浄に用いた洗浄液を回収し、電解に供して過硫酸濃度を高めた後、さらに洗浄液として前記洗浄に供することを特徴とする請求項7~10のいずれかに記載の基板洗浄方法。
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US10147619B2 (en) | 2015-08-27 | 2018-12-04 | Toshiba Memory Corporation | Substrate treatment apparatus, substrate treatment method, and etchant |
JP6751326B2 (ja) * | 2016-09-16 | 2020-09-02 | キオクシア株式会社 | 基板処理装置および半導体装置の製造方法 |
JP6850650B2 (ja) * | 2017-03-27 | 2021-03-31 | 株式会社Screenホールディングス | 基板処理方法および基板処理装置 |
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US11056348B2 (en) * | 2018-04-05 | 2021-07-06 | Invensas Bonding Technologies, Inc. | Bonding surfaces for microelectronics |
CN110369367A (zh) * | 2019-08-01 | 2019-10-25 | 山东泰开高压开关有限公司 | 降低废液量的方法及装置 |
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US11380776B2 (en) | 2020-09-29 | 2022-07-05 | Taiwan Semiconductor Manufacturing Company, Ltd. | Field-effect transistor device with gate spacer structure |
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008071801A (ja) * | 2006-09-12 | 2008-03-27 | Toshiba Corp | エッチング液、エッチング方法および電子部品の製造方法 |
JP2012074601A (ja) * | 2010-09-29 | 2012-04-12 | Dainippon Screen Mfg Co Ltd | 基板処理装置および基板処理方法 |
JP2012169562A (ja) * | 2011-02-16 | 2012-09-06 | Kurita Water Ind Ltd | 窒化物半導体材料の表面処理方法および表面処理システム |
JP2012204424A (ja) * | 2011-03-24 | 2012-10-22 | Toshiba Corp | 半導体基板の表面処理方法および基板処理装置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3467411B2 (ja) | 1998-08-07 | 2003-11-17 | 松下電器産業株式会社 | エッチング液,その製造方法及びエッチング方法 |
JP3889271B2 (ja) | 2000-12-15 | 2007-03-07 | 株式会社東芝 | 半導体装置の製造方法 |
JP4355201B2 (ja) * | 2003-12-02 | 2009-10-28 | 関東化学株式会社 | タングステン金属除去液及びそれを用いたタングステン金属の除去方法 |
CN1914710A (zh) | 2003-12-30 | 2007-02-14 | 艾奎昂有限责任公司 | 在基片处理过程中选择性蚀刻氮化硅的系统和方法 |
TWI364450B (en) * | 2004-08-09 | 2012-05-21 | Kao Corp | Polishing composition |
JP4462146B2 (ja) * | 2004-09-17 | 2010-05-12 | 栗田工業株式会社 | 硫酸リサイクル型洗浄システムおよび硫酸リサイクル型過硫酸供給装置 |
KR101349491B1 (ko) * | 2005-12-20 | 2014-01-08 | 미츠비시 가스 가가쿠 가부시키가이샤 | 배선 기판의 잔사 제거용 조성물 및 세정 방법 |
WO2007130471A2 (en) * | 2006-05-01 | 2007-11-15 | The Charles Stark Draper Laboratory, Inc. | Systems and methods for high density multi-component modules |
US7514797B2 (en) * | 2007-05-31 | 2009-04-07 | Taiwan Semiconductor Manufacturing Company, Ltd. | Multi-die wafer level packaging |
US8778803B2 (en) | 2007-09-21 | 2014-07-15 | Hitachi Chemical Company, Ltd. | CPM slurry for silicon film polishing and polishing method |
CN101465273B (zh) * | 2007-12-18 | 2011-04-20 | 中芯国际集成电路制造(上海)有限公司 | 用于减少晶片表面缺陷的湿式蚀刻方法及其装置 |
CN110189995A (zh) * | 2010-12-10 | 2019-08-30 | 东京毅力科创Fsi公司 | 用于从衬底选择性地移除氮化物的方法 |
-
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Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008071801A (ja) * | 2006-09-12 | 2008-03-27 | Toshiba Corp | エッチング液、エッチング方法および電子部品の製造方法 |
JP2012074601A (ja) * | 2010-09-29 | 2012-04-12 | Dainippon Screen Mfg Co Ltd | 基板処理装置および基板処理方法 |
JP2012169562A (ja) * | 2011-02-16 | 2012-09-06 | Kurita Water Ind Ltd | 窒化物半導体材料の表面処理方法および表面処理システム |
JP2012204424A (ja) * | 2011-03-24 | 2012-10-22 | Toshiba Corp | 半導体基板の表面処理方法および基板処理装置 |
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CN104871296A (zh) | 2015-08-26 |
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