JP2023154963A - Polishing liquid composition for silicon substrate - Google Patents
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- 238000005498 polishing Methods 0.000 title claims abstract description 384
- 239000000203 mixture Substances 0.000 title claims abstract description 133
- 239000007788 liquid Substances 0.000 title claims abstract description 130
- 239000000758 substrate Substances 0.000 title claims abstract description 127
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 86
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 86
- 239000010703 silicon Substances 0.000 title claims abstract description 86
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 71
- 238000000034 method Methods 0.000 claims abstract description 60
- 229920003169 water-soluble polymer Polymers 0.000 claims abstract description 34
- 125000003277 amino group Chemical group 0.000 claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 claims abstract description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000004065 semiconductor Substances 0.000 claims abstract description 25
- 125000002768 hydroxyalkyl group Chemical group 0.000 claims abstract description 13
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 5
- 125000004029 hydroxymethyl group Chemical group [H]OC([H])([H])* 0.000 claims description 4
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 2
- 239000012141 concentrate Substances 0.000 abstract description 55
- 238000003860 storage Methods 0.000 abstract description 41
- 230000006872 improvement Effects 0.000 description 26
- 238000004140 cleaning Methods 0.000 description 18
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 16
- 230000002776 aggregation Effects 0.000 description 16
- -1 2-oxazoline compound Chemical class 0.000 description 15
- 238000005259 measurement Methods 0.000 description 14
- 238000007518 final polishing process Methods 0.000 description 13
- 238000007517 polishing process Methods 0.000 description 12
- 229920002873 Polyethylenimine Polymers 0.000 description 11
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 11
- 239000011164 primary particle Substances 0.000 description 11
- 125000000467 secondary amino group Chemical group [H]N([*:1])[*:2] 0.000 description 11
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 10
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 10
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 10
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 10
- 238000004220 aggregation Methods 0.000 description 10
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 230000007547 defect Effects 0.000 description 9
- 238000001035 drying Methods 0.000 description 9
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 9
- 229910021529 ammonia Inorganic materials 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 239000011163 secondary particle Substances 0.000 description 8
- 239000000377 silicon dioxide Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 229920001223 polyethylene glycol Polymers 0.000 description 7
- CTKINSOISVBQLD-UHFFFAOYSA-N Glycidol Chemical class OCC1CO1 CTKINSOISVBQLD-UHFFFAOYSA-N 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 6
- 239000008119 colloidal silica Substances 0.000 description 6
- 238000011156 evaluation Methods 0.000 description 6
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 6
- 229920005591 polysilicon Polymers 0.000 description 6
- 230000003746 surface roughness Effects 0.000 description 6
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 5
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 5
- 229920006317 cationic polymer Polymers 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 229910021642 ultra pure water Inorganic materials 0.000 description 5
- 239000012498 ultrapure water Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000002296 dynamic light scattering Methods 0.000 description 4
- 150000002118 epoxides Chemical class 0.000 description 4
- 238000001644 13C nuclear magnetic resonance spectroscopy Methods 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- 239000002202 Polyethylene glycol Substances 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- 239000006061 abrasive grain Substances 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 238000013459 approach Methods 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- 238000005227 gel permeation chromatography Methods 0.000 description 3
- 125000004433 nitrogen atom Chemical group N* 0.000 description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 3
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- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 2
- 238000004438 BET method Methods 0.000 description 2
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 2
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-ZSJDYOACSA-N Heavy water Chemical compound [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- AVXURJPOCDRRFD-UHFFFAOYSA-N Hydroxylamine Chemical compound ON AVXURJPOCDRRFD-UHFFFAOYSA-N 0.000 description 2
- GLUUGHFHXGJENI-UHFFFAOYSA-N Piperazine Chemical compound C1CNCCN1 GLUUGHFHXGJENI-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 239000001099 ammonium carbonate Substances 0.000 description 2
- 150000007514 bases Chemical class 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 125000002091 cationic group Chemical group 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 239000012459 cleaning agent Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
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- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- NAQMVNRVTILPCV-UHFFFAOYSA-N hexane-1,6-diamine Chemical compound NCCCCCCN NAQMVNRVTILPCV-UHFFFAOYSA-N 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
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- 238000010979 pH adjustment Methods 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 2
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 2
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 2
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 description 2
- PVOAHINGSUIXLS-UHFFFAOYSA-N 1-Methylpiperazine Chemical compound CN1CCNCC1 PVOAHINGSUIXLS-UHFFFAOYSA-N 0.000 description 1
- HXKKHQJGJAFBHI-UHFFFAOYSA-N 1-aminopropan-2-ol Chemical compound CC(O)CN HXKKHQJGJAFBHI-UHFFFAOYSA-N 0.000 description 1
- BBBUAWSVILPJLL-UHFFFAOYSA-N 2-(2-ethylhexoxymethyl)oxirane Chemical compound CCCCC(CC)COCC1CO1 BBBUAWSVILPJLL-UHFFFAOYSA-N 0.000 description 1
- IWSZDQRGNFLMJS-UHFFFAOYSA-N 2-(dibutylamino)ethanol Chemical compound CCCCN(CCO)CCCC IWSZDQRGNFLMJS-UHFFFAOYSA-N 0.000 description 1
- LKMJVFRMDSNFRT-UHFFFAOYSA-N 2-(methoxymethyl)oxirane Chemical compound COCC1CO1 LKMJVFRMDSNFRT-UHFFFAOYSA-N 0.000 description 1
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 1
- BFSVOASYOCHEOV-UHFFFAOYSA-N 2-diethylaminoethanol Chemical compound CCN(CC)CCO BFSVOASYOCHEOV-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- UEEJHVSXFDXPFK-UHFFFAOYSA-N N-dimethylaminoethanol Chemical compound CN(C)CCO UEEJHVSXFDXPFK-UHFFFAOYSA-N 0.000 description 1
- OPKOKAMJFNKNAS-UHFFFAOYSA-N N-methylethanolamine Chemical compound CNCCO OPKOKAMJFNKNAS-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- SLINHMUFWFWBMU-UHFFFAOYSA-N Triisopropanolamine Chemical compound CC(O)CN(CC(C)O)CC(C)O SLINHMUFWFWBMU-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- LHIJANUOQQMGNT-UHFFFAOYSA-N aminoethylethanolamine Chemical compound NCCNCCO LHIJANUOQQMGNT-UHFFFAOYSA-N 0.000 description 1
- IMUDHTPIFIBORV-UHFFFAOYSA-N aminoethylpiperazine Chemical compound NCCN1CCNCC1 IMUDHTPIFIBORV-UHFFFAOYSA-N 0.000 description 1
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 150000003868 ammonium compounds Chemical class 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- LDDQLRUQCUTJBB-UHFFFAOYSA-O azanium;hydrofluoride Chemical compound [NH4+].F LDDQLRUQCUTJBB-UHFFFAOYSA-O 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 description 1
- LVTYICIALWPMFW-UHFFFAOYSA-N diisopropanolamine Chemical compound CC(O)CNCC(C)O LVTYICIALWPMFW-UHFFFAOYSA-N 0.000 description 1
- 229940043276 diisopropanolamine Drugs 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 125000003700 epoxy group Chemical group 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910021485 fumed silica Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000003002 pH adjusting agent Substances 0.000 description 1
- 229960005141 piperazine Drugs 0.000 description 1
- 229960003506 piperazine hexahydrate Drugs 0.000 description 1
- AVRVZRUEXIEGMP-UHFFFAOYSA-N piperazine;hexahydrate Chemical compound O.O.O.O.O.O.C1CNCCN1 AVRVZRUEXIEGMP-UHFFFAOYSA-N 0.000 description 1
- 229920000083 poly(allylamine) Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 150000003141 primary amines Chemical class 0.000 description 1
- ULWHHBHJGPPBCO-UHFFFAOYSA-N propane-1,1-diol Chemical group CCC(O)O ULWHHBHJGPPBCO-UHFFFAOYSA-N 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 150000003335 secondary amines Chemical class 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000010421 standard material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003512 tertiary amines Chemical class 0.000 description 1
- CZDYPVPMEAXLPK-UHFFFAOYSA-N tetramethylsilane Chemical compound C[Si](C)(C)C CZDYPVPMEAXLPK-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
本開示は、シリコン基板用研磨液組成物、並びにこれを用いた研磨方法、半導体基板の製造方法に関する。 The present disclosure relates to a polishing liquid composition for silicon substrates, a polishing method using the same, and a method for manufacturing a semiconductor substrate.
半導体基板の製造に用いられるシリコン基板の研磨に用いられる研磨液組成物として、シリカ粒子を含有する研磨液組成物が知られている。この種の研磨液組成物においては、シリカ粒子の凝集に起因するシリコン基板の表面欠陥(LPD:Light point defects)の発生や、凝集物を除去するために研磨液組成物をろ過する場合のフィルタ目詰まりが問題となっている(例えば、特許文献1参照)。また、研磨後の基板の表面品質を向上させる目的で、水溶性高分子を含む研磨液組成物が知られている(特許文献2、3参照)。 2. Description of the Related Art Polishing liquid compositions containing silica particles are known as polishing liquid compositions used for polishing silicon substrates used in the manufacture of semiconductor substrates. In this type of polishing liquid composition, the occurrence of surface defects (LPD: Light point defects) on the silicon substrate due to agglomeration of silica particles, and the need for a filter when filtering the polishing liquid composition to remove aggregates. Clogging has become a problem (see, for example, Patent Document 1). Further, polishing liquid compositions containing water-soluble polymers are known for the purpose of improving the surface quality of a substrate after polishing (see Patent Documents 2 and 3).
特許文献1では、シリカ粒子等の研磨材と、2-オキサゾリン系化合物又は2-オキサジン系化合物由来の構成単位を有する重合体と、を含有する研磨液組成物が提案されている。
特許文献2では、砥粒と、塩基性化合物と、窒素含有基を含むカチオン性水溶性高分子(例えば、ポリエチレンイミン)と、を含有する研磨液組成物が提案されている。
特許文献3では、仕上げ研磨の前段階の研磨(中間研磨)に用いられる研磨用組成物であって、シリカ粒子等の砥粒と、塩基性化合物と、重量平均分子量が30×104より高い水溶性高分子(例えば、ヒドロキシエチルセルロース)と、分散剤とを含有する研磨用組成物が提案されている。
Patent Document 1 proposes a polishing liquid composition containing an abrasive such as silica particles and a polymer having a structural unit derived from a 2-oxazoline compound or a 2-oxazine compound.
Patent Document 2 proposes a polishing liquid composition containing abrasive grains, a basic compound, and a cationic water-soluble polymer containing a nitrogen-containing group (for example, polyethyleneimine).
Patent Document 3 discloses a polishing composition used for polishing (intermediate polishing) before final polishing, which comprises abrasive grains such as silica particles, a basic compound, and a weight average molecular weight higher than 30 x 104 . Polishing compositions containing a water-soluble polymer (eg, hydroxyethyl cellulose) and a dispersant have been proposed.
しかし、特許文献1、3の研磨液組成物を用いた研磨では、研磨速度が十分とはいえない。
特許文献2の研磨液組成物を用いると、窒素含有基を含むカチオン性水溶性高分子によりシリカ粒子が凝集し、スクラッチの発生などシリコン基板の表面状態が悪化するという問題がある。
さらに、通常、研磨液組成物は、濃縮物の状態で保管、輸送されるものであり、濃縮物での保存安定性も要求される。
However, polishing using the polishing liquid compositions of Patent Documents 1 and 3 cannot be said to have a sufficient polishing rate.
When the polishing liquid composition of Patent Document 2 is used, there is a problem in that the silica particles aggregate due to the cationic water-soluble polymer containing a nitrogen-containing group, resulting in deterioration of the surface condition of the silicon substrate such as generation of scratches.
Furthermore, the polishing liquid composition is usually stored and transported in the form of a concentrate, and storage stability in the form of a concentrate is also required.
本開示は、研磨速度の向上と濃縮物の保存安定性とを両立できるシリコン基板用研磨液組成物、及びこれを用いたシリコン基板の研磨方法並びに半導体基板の製造方法を提供する。 The present disclosure provides a polishing liquid composition for a silicon substrate that can achieve both an improvement in polishing rate and storage stability of a concentrate, a method for polishing a silicon substrate using the same, and a method for manufacturing a semiconductor substrate.
本開示は、一態様において、シリカ粒子(成分A)と、ヒドロキシアルキル基が結合したアミノ基を有する水溶性高分子(成分B)と、水と、を含む、シリコン基板用研磨液組成物に関する。 In one aspect, the present disclosure relates to a polishing liquid composition for silicon substrates, which includes silica particles (component A), a water-soluble polymer having an amino group to which a hydroxyalkyl group is bonded (component B), and water. .
本開示は、一態様において、本開示の研磨液組成物を用いて被研磨シリコン基板を研磨する工程を含む、シリコン基板の研磨方法に関する。 In one aspect, the present disclosure relates to a method for polishing a silicon substrate, including a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure.
本開示は、一態様において、シリコン基板の仕上げ研磨を行う仕上げ研磨工程2と、仕上げ研磨工程2よりも前の研磨工程である仕上げ研磨工程1とを含み、仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われるシリコン基板の研磨方法であって、仕上げ研磨工程1では、本開示の研磨液組成物を用いて研磨し、仕上げ研磨工程2では、シリカ粒子及び水溶性高分子を含む研磨液組成物を用いて研磨する、シリコン基板の研磨方法に関する。 In one aspect, the present disclosure includes a final polishing process 2 for final polishing a silicon substrate, and a final polishing process 1 that is a polishing process before the final polishing process 2, and the final polishing process 1 and the final polishing process 2 A method of polishing a silicon substrate in which the following steps are performed in this order, wherein in the final polishing step 1, polishing is performed using a polishing liquid composition of the present disclosure, and in the final polishing step 2, a polishing composition containing silica particles and a water-soluble polymer is used. The present invention relates to a method of polishing a silicon substrate using a polishing liquid composition.
本開示は、一態様において、本開示の研磨方法を行うことを含む、半導体基板の製造方法に関する。 In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate, which includes performing the polishing method of the present disclosure.
本開示によれば、研磨速度の向上と濃縮物の保存安定性とを両立できるシリコン基板用研磨液組成物、及び該研磨液組成物を用いたシリコン基板の研磨方法、並びに半導体基板の製造方法を提供できる。 According to the present disclosure, a polishing liquid composition for a silicon substrate that can achieve both an improvement in polishing rate and storage stability of a concentrate, a method for polishing a silicon substrate using the polishing liquid composition, and a method for manufacturing a semiconductor substrate. can be provided.
本開示は、シリカ粒子及び特定のアミノ基含有水溶性高分子を含有するシリコン基板用研磨液組成物を用いることにより、シリコン基板を高速研磨でき、濃縮物の保存安定性に優れるという知見に基づく。 The present disclosure is based on the knowledge that by using a polishing liquid composition for silicon substrates containing silica particles and a specific amino group-containing water-soluble polymer, silicon substrates can be polished at high speed and the concentrate has excellent storage stability. .
すなわち、本開示は、一態様において、シリカ粒子(成分A)と、ヒドロキシアルキル基が結合したアミノ基を有する水溶性高分子(成分B)と、水と、を含有する、シリコン基板用研磨液組成物(以下、「本開示の研磨液組成物」ともいう)に関する。 That is, in one aspect, the present disclosure provides a silicon substrate polishing liquid containing silica particles (component A), a water-soluble polymer having an amino group to which a hydroxyalkyl group is bonded (component B), and water. The present invention relates to a composition (hereinafter also referred to as "polishing liquid composition of the present disclosure").
本開示によれば、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立できるシリコン基板用研磨液組成物を提供できる。 According to the present disclosure, in one or more embodiments, it is possible to provide a polishing liquid composition for silicon substrates that can achieve both improvement in polishing rate and storage stability of a concentrate.
本開示の効果発現機構の詳細は明らかではないが、以下のように推察される。
アルカリ性の研磨条件においては、シリカ粒子及び被研磨シリコン基板はともに負電荷を有し、静電反発力が発生している。そのため、シリカ粒子はシリコン基板に接近することが難しく、研磨速度は十分に発現しないと考えられる。一方、研磨液に配合されたカチオン性ポリマー(例えば、ポリエチレンイミン)は、シリカ粒子及びシリコン基板の負電荷を減少させて、さらにカチオン性ポリマー自身がバインダーとして作用するため、シリコン基板へのシリカ粒子の接近を促進することで研磨速度向上効果がある。しかし、同時にポリエチレンイミンのようなカチオン性ポリマーはシリカ粒子間のバインダーにもなるため、シリカ粒子が凝集しやすく、さらにシリカ濃度の高い濃縮液ではシリカの沈殿が生じてしまう。
本開示では、ヒドロキシアルキル基が結合したアミノ基を有する水溶性高分子、すなわち、アミノ基に立体反発基をもつカチオン性ポリマーを研磨液に配合する。これにより、シリカ砥粒及びシリコン基板の負電荷を減少させる効果は残し、シリカ粒子の接近促進効果(すなわち研磨速度向上効果)が発揮される。さらに、シリカ粒子の表面を覆うカチオン性ポリマーが立体反発基をもつことで、シリカ粒子間の凝集を緩和する効果を兼ね備えている。そのため、シリカ粒子の凝集を抑制でき、研磨速度の向上と濃縮物の保存安定性とを両立できると考えられる。
ただし、本開示はこれらのメカニズムに限定して解釈されなくてもよい。
Although the details of the effect expression mechanism of the present disclosure are not clear, it is presumed as follows.
Under alkaline polishing conditions, both the silica particles and the silicon substrate to be polished have negative charges, and electrostatic repulsion is generated. Therefore, it is difficult for silica particles to approach the silicon substrate, and it is thought that a sufficient polishing rate is not achieved. On the other hand, the cationic polymer (for example, polyethyleneimine) blended into the polishing liquid reduces the negative charge on the silica particles and the silicon substrate, and the cationic polymer itself acts as a binder, so the silica particles on the silicon substrate The polishing rate can be improved by promoting the approach of the two. However, since a cationic polymer such as polyethyleneimine also acts as a binder between silica particles, the silica particles tend to aggregate, and furthermore, in a concentrated solution with a high silica concentration, silica precipitates.
In the present disclosure, a water-soluble polymer having an amino group to which a hydroxyalkyl group is bonded, that is, a cationic polymer having a steric repulsion group in the amino group, is blended into a polishing liquid. As a result, the effect of reducing the negative charges of the silica abrasive grains and the silicon substrate remains, and the effect of promoting the approach of the silica particles (ie, the effect of improving the polishing rate) is exhibited. Furthermore, the cationic polymer covering the surface of the silica particles has a steric repulsion group, which also has the effect of mitigating aggregation between silica particles. Therefore, it is considered that agglomeration of silica particles can be suppressed, and both improvement in polishing rate and storage stability of the concentrate can be achieved.
However, the present disclosure does not need to be interpreted as being limited to these mechanisms.
[被研磨シリコン基板]
本開示の研磨液組成物は、シリコン基板用研磨組成物であり、例えば、半導体基板の製造方法における被研磨シリコン基板を研磨する研磨工程や、シリコン基板の研磨方法における被研磨シリコン基板を研磨する研磨工程に用いられうる。本開示の研磨液組成物を用いて研磨される被研磨シリコン基板としては、一又は複数の実施形態において、シリコン基板等が挙げられ、一又は複数の実施形態において、単結晶シリコン基板、ポリシリコン基板、ポリシリコン膜を有する基板、SiN基板等が挙げられ、本開示の研磨液組成物の効果が発揮される観点から、単結晶シリコン基板又はポリシリコン基板が好ましく、単結晶シリコン基板がより好ましい。
[Silicon substrate to be polished]
The polishing liquid composition of the present disclosure is a polishing composition for a silicon substrate, and is used, for example, in a polishing step of polishing a silicon substrate to be polished in a method of manufacturing a semiconductor substrate, or in a polishing process of polishing a silicon substrate to be polished in a method of polishing a silicon substrate. It can be used in polishing processes. In one or more embodiments, the silicon substrate to be polished polished using the polishing liquid composition of the present disclosure includes a silicon substrate, etc. In one or more embodiments, a single crystal silicon substrate, a polysilicon substrate, etc. A substrate, a substrate having a polysilicon film, a SiN substrate, etc. may be mentioned, and from the viewpoint of exhibiting the effects of the polishing liquid composition of the present disclosure, a single crystal silicon substrate or a polysilicon substrate is preferable, and a single crystal silicon substrate is more preferable. .
[シリカ粒子(成分A)]
本開示の研磨液組成物は、研磨材としてシリカ粒子(以下、「成分A」ともいう)を含有する。成分Aとしては、コロイダルシリカ、フュームドシリカ、粉砕シリカ、又はそれらを表面修飾したシリカ等が挙げられ、研磨速度の向上と濃縮物の保存安定性とを両立する観点、シリカ粒子の凝集抑制の観点、及び、表面粗さ(ヘイズ)、表面欠陥(LPD)及びスクラッチの低減等の表面品質の向上の観点から、コロイダルシリカが好ましい。成分Aは、1種でもよいし、2種以上の組合せでもよい。
[Silica particles (component A)]
The polishing liquid composition of the present disclosure contains silica particles (hereinafter also referred to as "component A") as an abrasive. Component A includes colloidal silica, fumed silica, pulverized silica, or silica surface-modified with these, and is useful for achieving both improvement in polishing speed and storage stability of concentrates, and for suppressing agglomeration of silica particles. Colloidal silica is preferred from the viewpoint of improving surface quality such as reduction of surface roughness (haze), surface defects (LPD), and scratches. Component A may be used alone or in combination of two or more.
成分Aの使用形態としては、操作性の観点から、スラリー状が好ましい。本開示の研磨液組成物に含まれる成分Aがコロイダルシリカである場合、アルカリ金属やアルカリ土類金属等によるシリコン基板の汚染を防止する観点から、コロイダルシリカは、アルコキシシランの加水分解物から得たものであることが好ましい。アルコキシシランの加水分解物から得られるシリカ粒子は、従来から公知の方法によって作製できる。 From the viewpoint of operability, component A is preferably used in a slurry form. When component A contained in the polishing liquid composition of the present disclosure is colloidal silica, the colloidal silica is obtained from a hydrolyzate of alkoxysilane from the viewpoint of preventing contamination of the silicon substrate with alkali metals, alkaline earth metals, etc. It is preferable that the Silica particles obtained from a hydrolyzate of alkoxysilane can be produced by conventionally known methods.
成分Aの平均一次粒子径は、研磨速度を維持する観点から、10nm以上が好ましく、20nm以上がより好ましく、30nm以上が更に好ましく、そして、表面粗さ(ヘイズ)、表面欠陥(LPD)及びスクラッチの低減等の表面品質の向上の観点から、50nm以下が好ましく、45nm以下がより好ましく、40nm以下が更に好ましい。より具体的には、成分Aの平均一次粒子径は、10nm以上50nm以下が好ましく、20nm以上45nm以下がより好ましく、30nm以上40nm以下が更に好ましい。
本開示において、成分Aの平均一次粒子径は、窒素吸着法(BET法)によって算出される比表面積S(m2/g)を用いて算出される。平均一次粒子径の値は、実施例に記載する方法で測定される値である。
From the viewpoint of maintaining the polishing rate, the average primary particle diameter of component A is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more, and the average primary particle size of component A is from the viewpoint of maintaining the polishing rate. From the viewpoint of improving surface quality such as reduction in , the thickness is preferably 50 nm or less, more preferably 45 nm or less, and even more preferably 40 nm or less. More specifically, the average primary particle diameter of component A is preferably 10 nm or more and 50 nm or less, more preferably 20 nm or more and 45 nm or less, and even more preferably 30 nm or more and 40 nm or less.
In the present disclosure, the average primary particle diameter of component A is calculated using the specific surface area S (m 2 /g) calculated by the nitrogen adsorption method (BET method). The value of the average primary particle diameter is a value measured by the method described in the Examples.
成分Aの平均二次粒子径は、研磨速度を維持する観点から、20nm以上が好ましく、30nm以上がより好ましく、40nm以上が更に好ましく、60nm以上が更に好ましく、表面粗さ(ヘイズ)、表面欠陥(LPD)及びスクラッチの低減等の表面品質の向上の観点から、100nm以下が好ましく、90nm以下がより好ましく、80nm以下が更に好ましい。同様の観点から、成分Aの平均二次粒子径は、20nm以上100nm以下が好ましく、40nm以上90nm以下がより好ましく、60nm以上80nm以下が更に好ましい。
本開示において、平均二次粒子径は、動的光散乱(DLS)法によって測定される値であり、実施例に記載する方法で測定される値である。
From the viewpoint of maintaining the polishing rate, the average secondary particle diameter of component A is preferably 20 nm or more, more preferably 30 nm or more, even more preferably 40 nm or more, and even more preferably 60 nm or more, and it is suitable for surface roughness (haze) and surface defects. (LPD) and from the viewpoint of improving surface quality such as reducing scratches, the thickness is preferably 100 nm or less, more preferably 90 nm or less, and even more preferably 80 nm or less. From the same viewpoint, the average secondary particle diameter of component A is preferably 20 nm or more and 100 nm or less, more preferably 40 nm or more and 90 nm or less, and even more preferably 60 nm or more and 80 nm or less.
In the present disclosure, the average secondary particle diameter is a value measured by a dynamic light scattering (DLS) method, and is a value measured by the method described in Examples.
成分Aの会合度は、表面粗さ(ヘイズ)、表面欠陥(LPD)及びスクラッチの低減等の表面品質の向上の観点から、3以下が好ましく、2.5以下がより好ましく、2.3以下が更に好ましく、そして、研磨速度の向上及び表面品質の向上の観点から、1.1以上が好ましく、1.5以上がより好ましく、1.8以上が更に好ましい。 The degree of association of component A is preferably 3 or less, more preferably 2.5 or less, and 2.3 or less, from the viewpoint of improving surface quality such as reducing surface roughness (haze), surface defects (LPD), and scratches. is more preferable, and from the viewpoint of improving the polishing rate and surface quality, it is preferably 1.1 or more, more preferably 1.5 or more, and even more preferably 1.8 or more.
本開示において、成分Aの会合度とは、シリカ粒子の形状を表す係数であり、下記式により算出される。
会合度=平均二次粒子径/平均一次粒子径
In the present disclosure, the degree of association of component A is a coefficient representing the shape of silica particles, and is calculated by the following formula.
Degree of association = average secondary particle size / average primary particle size
成分Aの会合度の調整方法としては、例えば、特開平6-254383号公報、特開平11-214338号公報、特開平11-60232号公報、特開2005-060217号公報、特開2005-060219号公報等に記載の方法を採用することができる。 Examples of methods for adjusting the degree of association of component A include JP-A-6-254383, JP-A-11-214338, JP-A-11-60232, JP-A-2005-060217, and JP-A-2005-060219. The method described in the above publication can be adopted.
成分Aの形状は、研磨速度の向上及び表面品質の向上の観点から、いわゆる球型及び/又はいわゆるマユ型であることが好ましい。 The shape of component A is preferably a so-called spherical shape and/or a so-called cocoon shape from the viewpoint of improving the polishing rate and surface quality.
本開示の研磨液組成物中の成分Aの含有量は、研磨速度の向上の観点から、SiO2換算で、0.1質量%以上が好ましく、0.2質量%以上がより好ましく、0.3質量%以上が更に好ましく、そして、シリカ粒子の凝集抑制の観点、濃縮物の保存安定性の観点、及び表面品質の向上の観点から、5質量%以下が好ましく、2.5質量%以下がより好ましく、1質量%以下が更により好ましい。よって、本開示の研磨液組成物中の成分Aの含有量は、0.1質量%以上5質量%以下が好ましく、0.2質量%以上2.5質量%以下がより好ましく、0.3質量%以上1質量%以下が更に好ましい。成分Aが2種以上の組合せの場合、成分Aの含有量はそれらの合計含有量をいう。 From the viewpoint of improving the polishing rate, the content of component A in the polishing liquid composition of the present disclosure is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and more preferably 0.2% by mass or more in terms of SiO 2 . It is more preferably 3% by mass or more, and from the viewpoint of suppressing agglomeration of silica particles, the storage stability of concentrates, and improving the surface quality, it is preferably 5% by mass or less, and 2.5% by mass or less. It is more preferably 1% by mass or less, and even more preferably 1% by mass or less. Therefore, the content of component A in the polishing liquid composition of the present disclosure is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.2% by mass or more and 2.5% by mass or less, and 0.3% by mass or more. It is more preferably 1% by mass or more and 1% by mass or less. When Component A is a combination of two or more types, the content of Component A refers to their total content.
[ヒドロキシアルキル基が結合したアミノ基を有する水溶性高分子(成分B)]
本開示の研磨液組成物は、ヒドロキシアルキル基が結合したアミノ基を有する水溶性高分子(以下、「成分B」ともいう)を含有する。成分Bは、一又は複数の実施形態において、主鎖に窒素原子を含み、主鎖の窒素原子にヒドロキシアルキル基が結合しているアミノ基を有するアミノ基含有水溶性高分子である。成分Bは、一又は複数の実施形態において、アミノ基を少なくとも1個以上有し、全アミノ基のうちの少なくとも一部のアミノ基の窒素原子にヒドロキシアルキル基が結合しているアミノ基含有水溶性高分子である。本開示において、「水溶性」とは、水(20℃)に対して0.5g/100mL以上の溶解度、好ましくは2g/100mL以上の溶解度を有することをいう。
前記ヒドロキシアルキル基は、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、好ましくは炭素数1以上5以下のヒドロキシアルキル基、より好ましくは炭素数1以上3以下のヒドロキシアルキル基が挙げられ、例えば、ヒドロキシメチル基、ヒドロキシエチル基、ヒドロキシプロピル基、ヒドロキシブチル基、プロパンジオール基等が挙げられる。
前記ヒドロキシアルキル基が結合したアミノ基は、一又は複数の実施形態において、立体反発基を有するアミノ基であり、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、アミノ基に対するエポキシド類による修飾基であることが好ましい。前記修飾基は、一又は複数の実施形態において、アミノ基とエポキシド類とが反応して形成される基である。一又は複数の実施形態において、成分Bの全アミノ基のうちの少なくとも一部のアミノ基がエポキシド類によって変性され、立体反発を有するアミノ基となる。エポキシド類としては、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、エチレンオキサイド(EO)、プロピレンオキサイド(PO)、グリシドール誘導体が好ましく、プロピレンオキサイド(PO)又はグリシドール誘導体がより好ましく、プロピレンオキサイド(PO)が更に好ましい。グリシドール誘導体としては、例えば、グリシドール、アルキルグリシジルエーテル等が挙げられ、入手性の観点、研磨速度の向上と濃縮物の保存安定性とを両立する観点、シリカ粒子の凝集抑制の観点から、グリシドールが好ましい。アルキルグリシジルエーテルのアルキル基は、入手性の観点から、炭素数1~8のアルキル基が好ましく、例えば、メチル基、エチル基、プロピル基、ブチル基、2-エチルヘキシル基等が挙げられる。アルキルグリシジルエーテルの具体例としては、メチルグリシジルエーテル、2-エチルヘキシルグリシジルエーテル等が挙げられる。
[Water-soluble polymer having an amino group bound to a hydroxyalkyl group (component B)]
The polishing liquid composition of the present disclosure contains a water-soluble polymer having an amino group to which a hydroxyalkyl group is bonded (hereinafter also referred to as "component B"). In one or more embodiments, component B is an amino group-containing water-soluble polymer that includes a nitrogen atom in its main chain and has an amino group to which a hydroxyalkyl group is bonded to the nitrogen atom in the main chain. In one or more embodiments, component B is an amino group-containing aqueous solution having at least one amino group and having a hydroxyalkyl group bonded to the nitrogen atom of at least some of the amino groups among all the amino groups. Polymer. In the present disclosure, "water-soluble" refers to having a solubility in water (20° C.) of 0.5 g/100 mL or more, preferably 2 g/100 mL or more.
In one or more embodiments, the hydroxyalkyl group is preferably a hydroxyalkyl group having 1 or more and 5 or less carbon atoms, more preferably a carbon number from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate. Examples include 1 to 3 hydroxyalkyl groups, such as hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, hydroxybutyl group, propanediol group, and the like.
In one or more embodiments, the amino group to which the hydroxyalkyl group is bonded is an amino group having a steric repulsion group, and from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate, Preferably, it is a modified group using epoxides. In one or more embodiments, the modification group is a group formed by reacting an amino group with an epoxide. In one or more embodiments, at least some of the amino groups of component B are modified with epoxides to become amino groups with steric repulsion. As the epoxides, ethylene oxide (EO), propylene oxide (PO), and glycidol derivatives are preferable, and propylene oxide (PO) or glycidol derivatives are more preferable from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate. Preferably, propylene oxide (PO) is more preferable. Examples of glycidol derivatives include glycidol, alkyl glycidyl ethers, etc. From the viewpoint of availability, improving the polishing rate and maintaining the storage stability of concentrates, and suppressing aggregation of silica particles, glycidol is preferred. preferable. From the viewpoint of availability, the alkyl group of the alkyl glycidyl ether is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, a 2-ethylhexyl group, and the like. Specific examples of alkyl glycidyl ether include methyl glycidyl ether, 2-ethylhexyl glycidyl ether, and the like.
成分Bは、一又は複数の実施形態において、第1級アミノ基又は第2級アミノ基を有する水溶性高分子をエポキシ類と反応させることで得ることができる。第1級アミノ基又は第2級アミノ基を有する水溶性高分子としては、例えば、ポリエチレンイミン、ポリアリルアミン、ポリジアリルアミン等が挙げられる。 In one or more embodiments, component B can be obtained by reacting a water-soluble polymer having a primary amino group or a secondary amino group with an epoxy. Examples of the water-soluble polymer having a primary amino group or a secondary amino group include polyethyleneimine, polyallylamine, polydiallylamine, and the like.
成分Bは、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、下記式(1)で表される構成を含むアミノ基含有水溶性高分子であることが好ましい。
成分Bは、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、第1級アミノ基又は第2級アミノ基を有する水溶性高分子の全アミノ基のうちの少なくとも一部のアミノ基がエポキシ類で変性されたアミノ基含有水溶性高分子であることが好ましい。 In one or more embodiments, component B is a total amino acid of a water-soluble polymer having a primary amino group or a secondary amino group, from the viewpoint of improving the polishing rate and improving the storage stability of the concentrate. It is preferable to use an amino group-containing water-soluble polymer in which at least some of the amino groups among the groups are modified with epoxies.
成分Bの全アミノ基中の第1級アミノ基及び第2級アミノ基の比率は、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリカ粒子の凝集抑制の観点から、50%以下が好ましく、40%以下がより好ましく、30%以下が更に好ましく、20%以下が更に好ましく、10%以下が更に好ましく、5%以下が更に好ましく、1%以下が更に好ましく、0%が更に好ましい。成分Bの全アミノ基中の第1級アミノ基及び第2級アミノ基の比率は、例えば、実施例に記載の方法により測定できる。 The ratio of primary amino groups and secondary amino groups in the total amino groups of component B is determined from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate, and from the viewpoint of suppressing aggregation of silica particles. , preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, even more preferably 20% or less, even more preferably 10% or less, even more preferably 5% or less, even more preferably 1% or less, 0 % is more preferable. The ratio of primary amino groups to secondary amino groups in all amino groups of component B can be measured, for example, by the method described in Examples.
成分Bとしては、例えば、上記式(1)の構成を含むポリエチレンイミン、プロピレンオキサイド(PO)とポリエチレンイミンとの反応物、グリシドールとポリエチレンイミンとの反応物等が挙げられる。 Examples of component B include polyethyleneimine having the structure of formula (1) above, a reaction product of propylene oxide (PO) and polyethyleneimine, a reaction product of glycidol and polyethyleneimine, and the like.
成分Bの重量平均分子量は、研磨速度の向上の観点から、200以上が好ましく、800以上がより好ましく、1,000以上が更に好ましく、1,500以上が更に好ましく、2,000以上が更に好ましく、そして、研磨速度の向上と濃縮物の保存安定性とを両立する観点、シリカ粒子の凝集抑制の観点、及び、表面品質の向上の観点から、200,000以下が好ましく、100,000以下がより好ましく、50,000以下が更に好ましく、30,000以下が更に好ましく、20,000以下が更に好ましく、15,000以下が更に好ましく、12,000以下が更に好ましい。より具体的には、成分Bの重量平均分子量は、200以上200,000以下が好ましく、800以上100,000以下がより好ましく、1,000以上50,000以下が更に好ましく、1,500以上30,000以下が更に好ましく、2,000以上20,000以下が更に好ましく、2,000以上15,000以下が更に好ましく、2,000以上12,000以下が更に好ましい。本開示における成分Bの重量平均分子量は、例えば、実施例に記載する方法により測定できる。 From the viewpoint of improving the polishing rate, the weight average molecular weight of component B is preferably 200 or more, more preferably 800 or more, even more preferably 1,000 or more, even more preferably 1,500 or more, and even more preferably 2,000 or more. , from the viewpoint of achieving both an improvement in polishing rate and storage stability of the concentrate, from the viewpoint of suppressing aggregation of silica particles, and from the viewpoint of improving surface quality, it is preferably 200,000 or less, and 100,000 or less. It is more preferably 50,000 or less, even more preferably 30,000 or less, even more preferably 20,000 or less, even more preferably 15,000 or less, and even more preferably 12,000 or less. More specifically, the weight average molecular weight of component B is preferably 200 or more and 200,000 or less, more preferably 800 or more and 100,000 or less, even more preferably 1,000 or more and 50,000 or less, and 1,500 or more and 30 ,000 or less, more preferably 2,000 or more and 20,000 or less, even more preferably 2,000 or more and 15,000 or less, even more preferably 2,000 or more and 12,000 or less. The weight average molecular weight of component B in the present disclosure can be measured, for example, by the method described in the Examples.
本開示の研磨液組成物中の成分Bの含有量は、研磨速度の向上の観点から、0.001質量%以上が好ましく、0.005質量%以上がより好ましく、0.008質量%以上が更に好ましく、そして、シリカ粒子の凝集抑制及び濃縮物の保存安定性の観点から、0.1質量%以下が好ましく、0.05質量%以下がより好ましく、0.03質量%以下が更に好ましく、0.02質量%以下が更に好ましい。より具体的には、成分Bの含有量は、0.001質量%以上0.1質量%以下が好ましく、0.005質量%以上0.05質量%以下がより好ましく、0.008質量%以上0.03質量%以下が更に好ましく、0.008質量%以上0.02質量%以下が更に好ましい。 From the viewpoint of improving the polishing rate, the content of component B in the polishing liquid composition of the present disclosure is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and 0.008% by mass or more. More preferably, from the viewpoint of suppressing aggregation of silica particles and storage stability of the concentrate, it is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, even more preferably 0.03% by mass or less, More preferably, it is 0.02% by mass or less. More specifically, the content of component B is preferably 0.001% by mass or more and 0.1% by mass or less, more preferably 0.005% by mass or more and 0.05% by mass or less, and 0.008% by mass or more. It is more preferably 0.03% by mass or less, and even more preferably 0.008% by mass or more and 0.02% by mass or less.
本開示の研磨液組成物中における成分Aの含有量に対する成分Bの含有量の比(質量比B/A)は、研磨速度の向上の観点から、0.002以上が好ましく、0.01以上がより好ましく、0.014以上が更に好ましく、そして、シリカ粒子の凝集抑制及び濃縮物の保存安定性の観点から、0.1以下が好ましく、0.06以下がより好ましく、0.04以下が更に好ましい。より具体的には、質量比B/Aは、0.002以上0.1以下が好ましく、0.01以上0.06以下がより好ましく、0.014以上0.04以下が更に好ましい。 The ratio of the content of component B to the content of component A in the polishing liquid composition of the present disclosure (mass ratio B/A) is preferably 0.002 or more, and 0.01 or more from the viewpoint of improving the polishing rate. is more preferable, 0.014 or more is still more preferable, and from the viewpoint of suppressing aggregation of silica particles and storage stability of the concentrate, it is preferably 0.1 or less, more preferably 0.06 or less, and 0.04 or less. More preferred. More specifically, the mass ratio B/A is preferably 0.002 or more and 0.1 or less, more preferably 0.01 or more and 0.06 or less, and even more preferably 0.014 or more and 0.04 or less.
[水]
本開示の研磨液組成物は、一又は複数の実施形態において、水を含んでいてもよい。水としては、例えば、イオン交換水や超純水等の水が挙げられる。本開示の研磨液組成物中の水の含有量は、例えば、成分A、成分B、及び後述する任意成分の残余とすることができる。
[water]
The polishing liquid composition of the present disclosure may contain water in one or more embodiments. Examples of water include water such as ion exchange water and ultrapure water. The content of water in the polishing liquid composition of the present disclosure can be, for example, component A, component B, and the remainder of optional components described below.
[含窒素塩基性化合物(成分C)]
本開示の研磨液組成物は、一又は複数の実施形態において、pHを調整する観点から、含窒素塩基性化合物(以下、「成分C」ともいう)をさらに含有することが好ましい。成分Cとしては、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリカ粒子の凝集抑制の観点から、水溶性の含窒素塩基性化合物であることが好ましい。本開示において、「水溶性」とは、水(20℃)に対して0.5g/100mL以上の溶解度、好ましくは2g/100mL以上の溶解度を有することをいう。本開示において、「水溶性の含窒素塩基性」とは、水に溶解したときに塩基性を示す含窒素化合物をいう。成分Cには、一又は複数の実施形態において、アミノ基含有水溶性高分子(成分B)は含まれないものとする。成分Cは、1種でもよいし、2種以上の組合せでもよい。
[Nitrogen-containing basic compound (component C)]
In one or more embodiments, the polishing liquid composition of the present disclosure preferably further contains a nitrogen-containing basic compound (hereinafter also referred to as "component C") from the viewpoint of adjusting pH. Component C is preferably a water-soluble nitrogen-containing basic compound from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate, and from the viewpoint of suppressing aggregation of silica particles. In the present disclosure, "water-soluble" refers to having a solubility in water (20° C.) of 0.5 g/100 mL or more, preferably 2 g/100 mL or more. In the present disclosure, "water-soluble nitrogen-containing basic" refers to a nitrogen-containing compound that exhibits basicity when dissolved in water. In one or more embodiments, component C does not include an amino group-containing water-soluble polymer (component B). Component C may be used alone or in combination of two or more.
成分Cとしては、一又は複数の実施形態において、アミン化合物及びアンモニウム化合物から選ばれる少なくとも1種が挙げられる。成分Cとしては、例えば、アンモニア、水酸化アンモニウム、炭酸アンモニウム、炭酸水素アンモニウム、ジメチルアミン、トリメチルアミン、ジエチルアミン、トリエチルアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、N一メチルエタノールアミン、N-メチル-N,N一ジエタノ-ルアミン、N,N-ジメチルエタノールアミン、N,N-ジエチルエタノールアミン、N,N-ジブチルエタノールアミン、N-(β-アミノエチル)エタノ-ルアミン、モノイソプロパノールアミン、ジイソプロパノールアミン、トリイソプロパノールアミン、エチレンジアミン、ヘキサメチレンジアミン、ピペラジン・六水和物、無水ピペラジン、1-(2-アミノエチル)ピペラジン、N-メチルピペラジン、ジエチレントリアミン、水酸化テトラメチルアンモニウム、及びヒドロキシアミンから選ばれる1種又は2種以上の組合せが挙げられる。なかでも、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリア粒子の凝集抑制の観点から、成分Cとしては、アンモニア、又は、アンモニアとヒドロキシアミンの混合物が好ましく、アンモニアがより好ましい。 In one or more embodiments, component C includes at least one selected from amine compounds and ammonium compounds. Component C includes, for example, ammonia, ammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, dimethylamine, trimethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyl-N , N-diethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-(β-aminoethyl)ethanolamine, monoisopropanolamine, diisopropanolamine , triisopropanolamine, ethylenediamine, hexamethylenediamine, piperazine hexahydrate, anhydrous piperazine, 1-(2-aminoethyl)piperazine, N-methylpiperazine, diethylenetriamine, tetramethylammonium hydroxide, and hydroxyamine. One type or a combination of two or more types can be mentioned. Among these, from the viewpoint of achieving both an improvement in polishing rate and storage stability of the concentrate, and from the viewpoint of suppressing agglomeration of Syrian particles, component C is preferably ammonia or a mixture of ammonia and hydroxyamine. is more preferable.
本開示の研磨液組成物が成分Cを含む場合、本開示の研磨液組成物中の成分Cの含有量は、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリカ粒子の凝集抑制の観点から、0.0005質量%以上が好ましく、0.001質量%以上がより好ましく、0.002質量%以上が更に好ましく、同様の観点から、0.05質量%以下が好ましく、0.03質量%以下がより好ましく、0.015質量%以下が更に好ましく、0.01質量%以下が更に好ましい。同様の観点から、本開示の研磨液組成物中の成分Cの含有量は、0.0005質量%以上0.05質量%以下が好ましく0.001質量%以上0.03質量%以下がより好ましく、0.002質量%以上0.015質量%以下が更に好ましく、0.002質量%以上0.01質量%以下が更に好ましい。成分Cが2種以上の組合せの場合、成分Cの含有量はそれらの合計含有量をいう。 When the polishing liquid composition of the present disclosure contains component C, the content of component C in the polishing liquid composition of the present disclosure is determined from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate, and silica. From the viewpoint of suppressing particle aggregation, it is preferably 0.0005% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.002% by mass or more, and from the same viewpoint, preferably 0.05% by mass or less. , more preferably 0.03% by mass or less, even more preferably 0.015% by mass or less, even more preferably 0.01% by mass or less. From the same viewpoint, the content of component C in the polishing liquid composition of the present disclosure is preferably 0.0005% by mass or more and 0.05% by mass or less, and more preferably 0.001% by mass or more and 0.03% by mass or less. , more preferably 0.002% by mass or more and 0.015% by mass or less, and still more preferably 0.002% by mass or more and 0.01% by mass or less. When component C is a combination of two or more types, the content of component C refers to their total content.
本開示の研磨液組成物が成分Cを含む場合、本開示の研磨液組成物中における成分Aの含有量に対する成分Cの含有量の比C/A(質量比C/A)は、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリカ粒子の凝集抑制の観点から、0.001以上が好ましく、0.002以上がより好ましく、0.004以上が更に好ましく、そして、同様の観点から、0.1以下が好ましく、0.06以下がより好ましく、0.02以下が更に好ましい。より具体的には、本開示の研磨液組成物中における質量比C/Aは、0.001以上0.1以下が好ましく、0.002以上0.06以下がより好ましく、0.004以上0.02以下が更に好ましい。 When the polishing liquid composition of the present disclosure contains component C, the ratio C/A (mass ratio C/A) of the content of component C to the content of component A in the polishing liquid composition of the present disclosure is the polishing rate. From the viewpoint of achieving both improvement in the storage stability of the concentrate and prevention of agglomeration of silica particles, it is preferably 0.001 or more, more preferably 0.002 or more, and even more preferably 0.004 or more. From the same viewpoint, it is preferably 0.1 or less, more preferably 0.06 or less, and even more preferably 0.02 or less. More specifically, the mass ratio C/A in the polishing liquid composition of the present disclosure is preferably from 0.001 to 0.1, more preferably from 0.002 to 0.06, and from 0.004 to 0. More preferably, it is .02 or less.
[その他の成分]
本開示の研磨液組成物は、本開示の効果が妨げられない範囲で、その他の成分をさらに含んでもよい。その他の成分としては、一又は複数の実施形態において、成分B以外の水溶性高分子、成分C以外のpH調整剤、防腐剤、アルコール類、キレート剤、及び酸化剤等が挙げられる。
[Other ingredients]
The polishing liquid composition of the present disclosure may further contain other components as long as the effects of the present disclosure are not impaired. In one or more embodiments, other components include water-soluble polymers other than component B, pH adjusters other than component C, preservatives, alcohols, chelating agents, oxidizing agents, and the like.
[pH]
本開示の研磨液組成物のpHは、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、シリカ粒子の凝集抑制の観点から、8.5超が好ましく、9以上がより好ましく、9.3以上が更に好ましく、そして、同様の観点から、14以下が好ましく、13以下がより好ましく、12.5以下が更に好ましく、12以下が更に好ましく、11.5以下が更に好ましく、11以下が更に好ましい。より具体的には、本開示の研磨液組成物のpHは、8.5超以上14以下が好ましく、9以上13以下がより好ましく、9以上12.5以下が更に好ましく、9以上12以下が更に好ましく、9.3以上11.5以下が更に好ましく、9.3以上11以下が更に好ましい。本開示の研磨液組成物のpHは、成分Cや公知のpH調整剤を用いて調整できる。本開示において、上記pHは、25℃における研磨液組成物のpHであり、pHメータを用いて測定できる。上記pHは、例えば、実施例に記載する方法で測定した値とすることができる。
[pH]
The pH of the polishing liquid composition of the present disclosure is preferably higher than 8.5, more preferably 9 or higher, from the viewpoint of improving the polishing rate and the storage stability of the concentrate, and from the viewpoint of suppressing aggregation of silica particles. Preferably, 9.3 or more is more preferable, and from the same viewpoint, 14 or less is preferable, 13 or less is more preferable, 12.5 or less is still more preferable, 12 or less is still more preferable, and 11.5 or less is still more preferable. It is more preferably 11 or less. More specifically, the pH of the polishing liquid composition of the present disclosure is preferably greater than or equal to 8.5 and less than or equal to 14, more preferably greater than or equal to 9 and less than or equal to 13, still more preferably greater than or equal to 9 and less than or equal to 12.5, and still more preferably greater than or equal to 9 and less than or equal to 12. It is more preferably 9.3 or more and 11.5 or less, even more preferably 9.3 or more and 11 or less. The pH of the polishing liquid composition of the present disclosure can be adjusted using component C or a known pH adjuster. In the present disclosure, the above pH is the pH of the polishing liquid composition at 25° C., and can be measured using a pH meter. The above pH can be, for example, a value measured by the method described in the Examples.
本開示の研磨液組成物は、例えば、成分A及び成分Bと水と、さらに所望により上述した任意成分(成分C及びその他の成分)とを公知の方法で配合することにより製造できる。すなわち、本開示の研磨液組成物は、例えば、少なくとも成分Aと成分Bと水とを配合することにより製造できる。したがって、本開示は、その他の態様において、少なくとも成分A、成分B及び水を配合する工程を含む、研磨液組成物の製造方法に関する。本開示において「配合する」とは、成分A、成分B、水、並びに、必要に応じて任意成分(成分C及びその他の成分)を同時に又は任意の順に混合することを含む。前記配合は、例えば、ホモミキサー、ホモジナイザー、超音波分散機、湿式ボールミル、又はビーズミル等の撹拌機等を用いて行うことができる。上記本開示の研磨液組成物の製造方法における各成分の好ましい配合量は、上述した本開示の研磨液組成物中の各成分の好ましい含有量と同じとすることができる。 The polishing liquid composition of the present disclosure can be produced, for example, by blending component A and component B, water, and optionally the above-mentioned optional components (component C and other components) by a known method. That is, the polishing liquid composition of the present disclosure can be produced, for example, by blending at least component A, component B, and water. Therefore, in another aspect, the present disclosure relates to a method for producing a polishing liquid composition, which includes a step of blending at least component A, component B, and water. In the present disclosure, "blending" includes mixing component A, component B, water, and, if necessary, optional components (component C and other components) simultaneously or in any order. The blending can be carried out using, for example, a stirrer such as a homomixer, a homogenizer, an ultrasonic disperser, a wet ball mill, or a bead mill. The preferable blending amount of each component in the method for manufacturing the polishing liquid composition of the present disclosure can be the same as the preferable content of each component in the polishing liquid composition of the present disclosure described above.
本開示において、「研磨液組成物中の各成分の含有量」は、使用時、すなわち、研磨液組成物の研磨への使用を開始する時点における各成分の含有量をいう。 In the present disclosure, "the content of each component in the polishing liquid composition" refers to the content of each component at the time of use, that is, at the time when the polishing liquid composition starts to be used for polishing.
本開示の研磨液組成物は、貯蔵及び輸送の観点から、濃縮物として製造され、使用時に希釈されてもよい。希釈倍率としては、製造及び輸送コストの観点、濃縮物の保存安定性の観点から、好ましくは2倍以上であり、より好ましくは5倍以上、更に好ましくは10倍以上、更に好ましくは15倍以上であり、濃縮物の保存安定性の観点から、好ましくは40倍以下であり、より好ましくは30倍以下、更に好ましくは20倍以下である。本開示の研磨液組成物の濃縮物は、使用時に各成分の含有量が、上述した含有量(すなわち、使用時の含有量)となるように水で希釈して使用することができる。本開示において研磨液組成物の濃縮物の「使用時」とは、研磨液組成物の濃縮物が希釈された状態をいう。 The polishing liquid composition of the present disclosure may be manufactured as a concentrate and diluted at the time of use for storage and transportation purposes. The dilution ratio is preferably 2 times or more, more preferably 5 times or more, still more preferably 10 times or more, and even more preferably 15 times or more, from the viewpoint of manufacturing and transportation costs and the storage stability of the concentrate. From the viewpoint of storage stability of the concentrate, it is preferably 40 times or less, more preferably 30 times or less, still more preferably 20 times or less. The concentrate of the polishing liquid composition of the present disclosure can be used by diluting it with water so that the content of each component becomes the above-mentioned content (that is, the content at the time of use). In the present disclosure, "at the time of use" of the concentrate of the polishing liquid composition refers to a state in which the concentrate of the polishing liquid composition is diluted.
本開示の研磨液組成物は、一又は複数の実施形態において、研磨速度の向上と表面品質の向上とを両立する観点から、シリコン基板の複数段階の研磨における仕上げ研磨に用いられることが好ましい。
本開示の研磨液組成物は、一又は複数の実施形態において、研磨速度の向上と表面品質の向上とを両立する観点から、シリコン基板の複数段階の研磨における仕上げ研磨の前段階にあたる研磨に用いることが好ましい。仕上げ研磨の前段階にあたる研磨は、一又は複数の実施形態において、シリコン基板の仕上げ研磨を行う仕上げ研磨工程2と、仕上げ研磨工程2より前の研磨工程である仕上げ研磨工程1とを含み、仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われるシリコン基板の研磨方法における、仕上げ研磨工程1が挙げられる。
In one or more embodiments, the polishing liquid composition of the present disclosure is preferably used for final polishing in multiple stages of polishing a silicon substrate from the viewpoint of improving both polishing speed and surface quality.
In one or more embodiments, the polishing liquid composition of the present disclosure is used for polishing that is a step before final polishing in multiple stages of polishing a silicon substrate, from the viewpoint of improving both polishing speed and surface quality. It is preferable. In one or more embodiments, the polishing that is a step before the final polishing includes a final polishing step 2 that performs final polishing of the silicon substrate, and a final polishing step 1 that is a polishing step before the final polishing step 2. An example is the final polishing step 1 in a silicon substrate polishing method in which the polishing step 1 and the final polishing step 2 are performed in this order.
[研磨液キット]
本開示は、一態様において、本開示の研磨液組成物を製造するための研磨液キット(以下、「本開示のキット」ともいう)に関する。本開示のキットによれば、研磨速度向上と濃縮物の保存安定性とを両立できる研磨液組成物が得られる。
本開示のキットとしては、一又は複数の実施形態において、成分A及び成分Bを含む溶液を含有する研磨液キットが挙げられる。前記溶液には、必要に応じて上述した任意成分(成分C、その他の成分)が含まれていてもよい。前記溶液は、使用時に、必要に応じて水を用いて希釈してもよい。
[Polishing liquid kit]
In one aspect, the present disclosure relates to a polishing liquid kit (hereinafter also referred to as "kit of the present disclosure") for manufacturing the polishing liquid composition of the present disclosure. According to the kit of the present disclosure, a polishing liquid composition that can achieve both an improvement in polishing speed and storage stability of a concentrate can be obtained.
In one or more embodiments, the kit of the present disclosure includes a polishing liquid kit containing a solution containing component A and component B. The solution may contain the above-mentioned optional components (component C and other components) as necessary. The solution may be diluted with water if necessary at the time of use.
[シリコン基板の研磨方法]
本開示は、一態様において、本開示の研磨液組成物を用いて被研磨シリコン基板を研磨する工程(以下、「研磨工程」ともいう)を含む、シリコン基板の研磨方法(以下、「本開示の研磨方法」ともいう)に関する。
本開示の研磨方法によれば、本開示の研磨液組成物を用いるため、研磨速度の向上と濃縮物の保存安定性とを両立できる。さらに、本開示の研磨方法によれば、表面粗さ(ヘイズ)、表面欠陥(LPD)及びスクラッチの低減等の表面品質を向上できる。
[Silicon substrate polishing method]
In one aspect, the present disclosure provides a method for polishing a silicon substrate (hereinafter referred to as "the present disclosure") including a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure (hereinafter also referred to as "polishing step"). (also referred to as "polishing method").
According to the polishing method of the present disclosure, since the polishing liquid composition of the present disclosure is used, it is possible to achieve both improvement in polishing rate and storage stability of the concentrate. Furthermore, according to the polishing method of the present disclosure, surface quality such as reduction of surface roughness (haze), surface defects (LPD), and scratches can be improved.
本開示の研磨方法における研磨工程では、例えば、研磨パッドを貼り付けた定盤に被研磨シリコン基板を押し付けて、3~20kPaの研磨圧力で被研磨シリコン基板を研磨することができる。本開示において、研磨圧力とは、研磨時に被研磨シリコン基板の被研磨面に加えられる定盤の圧力をいう。 In the polishing step in the polishing method of the present disclosure, for example, the silicon substrate to be polished can be pressed against a surface plate to which a polishing pad is attached, and the silicon substrate to be polished can be polished with a polishing pressure of 3 to 20 kPa. In the present disclosure, polishing pressure refers to the pressure of a surface plate applied to the polished surface of the silicon substrate to be polished during polishing.
本開示の研磨方法における研磨工程では、例えば、研磨パッドを貼り付けた定盤に被研磨シリコン基板を押し付けて、15℃以上40℃以下の研磨液組成物及び研磨パッド表面温度で被研磨シリコン基板を研磨することができる。研磨液組成物の温度及び研磨パッド表面温度としては、研磨速度向上と表面粗さ(ヘイズ)低減等の表面品質との両立の観点から、15℃以上又は20℃以上が好ましく、40℃以下又は30℃以下が好ましい。 In the polishing step in the polishing method of the present disclosure, for example, a silicon substrate to be polished is pressed against a surface plate to which a polishing pad is attached, and a polishing liquid composition of 15° C. or more and 40° C. or less and a polishing pad surface temperature are applied to the silicon substrate to be polished. can be polished. The temperature of the polishing liquid composition and the surface temperature of the polishing pad are preferably 15°C or higher or 20°C or higher, and 40°C or lower or The temperature is preferably 30°C or lower.
本開示の研磨方法における研磨工程は、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、仕上げ研磨工程であることが好ましい。 In one or more embodiments, the polishing step in the polishing method of the present disclosure is preferably a final polishing step from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate.
本開示の研磨方法における研磨工程は、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、表面品質の向上の観点から、仕上げ研磨工程の前段階にあたる研磨工程であることが好ましい。
仕上げ研磨工程の前段階にあたる研磨工程は、一又は複数の実施形態において、シリコン基板の仕上げ研磨を行う仕上げ研磨工程2と、仕上げ研磨工程2より前の研磨工程である仕上げ研磨工程1とを含み、仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われるシリコン基板の研磨方法における、仕上げ研磨工程1が挙げられる。研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、表面品質の向上の観点から、仕上げ研磨工程1と仕上げ研磨工程2とは、一又は複数の実施形態において、連続する研磨工程であることが好ましい。
研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、表面品質の向上の観点から、仕上げ研磨工程1では、本開示の研磨液組成物を用い、仕上げ研磨工程2では、シリカ粒子、HEC等の水溶性高分子を含む研磨液組成物を用いることが好ましい。仕上げ研磨工程2で用いる研磨液組成物に含まれる水溶性高分子としては、例えば、ヒドロキシエチルセルロース(HEC)、ポリビニルアルコール(PVA)、ポリビニルピロリドン(PVP)、(ポリエチレングリコール(PEG)等が挙げられる。仕上げ研磨工程2で用いられる研磨液組成物は、仕上げ研磨工程2で用いる研磨液組成物としては、従来から用いられている仕上げ研磨用の研磨液組成物を用いることができる。
すなわち、本開示は、一態様において、シリコン基板の仕上げ研磨を行う仕上げ研磨工程2と、仕上げ研磨工程2よりも前の研磨工程である仕上げ研磨工程1とを含み、仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われるシリコン基板の研磨方法であって、
仕上げ研磨工程1では、本開示の研磨液組成物を用いて研磨し、
仕上げ研磨工程2では、シリカ粒子及び水溶性高分子を含む研磨液組成物を用いて研磨する、シリコン基板の研磨方法に関する。
仕上げ研磨工程1及び2の研磨条件としては、上述した本開示の研磨方法における研磨工程と同様の研磨条件が挙げられる。
仕上げ研磨工程1と仕上げ研磨工程2は、1つの研磨定盤(同じ研磨定盤)で行うことができる。あるいは、仕上げ研磨工程1と仕上げ研磨工程2は、研磨定盤を変えて行う、すなわち、仕上げ研磨工程2を、仕上げ研磨工程1で使用した研磨定盤とは別の研磨定盤で行うこともできる。
In one or more embodiments, the polishing step in the polishing method of the present disclosure is performed before the final polishing step from the viewpoint of achieving both improvement in polishing speed and storage stability of the concentrate, and from the viewpoint of improving surface quality. Preferably, the polishing process is a stepwise polishing process.
In one or more embodiments, the polishing process that is a pre-stage of the final polishing process includes a final polishing process 2 that performs final polishing of the silicon substrate, and a final polishing process 1 that is a polishing process that precedes the final polishing process 2. , final polishing step 1 in a silicon substrate polishing method in which final polishing step 1 and final polishing step 2 are performed in this order. In one or more embodiments, the final polishing step 1 and the final polishing step 2 are continuous polishing steps from the viewpoint of achieving both an improvement in the polishing rate and the storage stability of the concentrate, and from the viewpoint of improving the surface quality. Preferably, it is a process.
From the viewpoint of achieving both an improvement in the polishing rate and the storage stability of the concentrate, and from the viewpoint of improving the surface quality, the polishing liquid composition of the present disclosure is used in the final polishing step 1, and the polishing liquid composition of the present disclosure is used in the final polishing step 2. It is preferable to use a polishing liquid composition containing particles and a water-soluble polymer such as HEC. Examples of water-soluble polymers contained in the polishing liquid composition used in the final polishing step 2 include hydroxyethyl cellulose (HEC), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), (polyethylene glycol (PEG)), etc. As the polishing liquid composition used in the final polishing step 2, a conventionally used polishing liquid composition for final polishing can be used.
That is, in one embodiment, the present disclosure includes a final polishing step 2 for final polishing a silicon substrate, and a final polishing step 1 which is a polishing step before the final polishing step 2, and the final polishing step 1 and the final polishing A method of polishing a silicon substrate in which step 2 is performed in this order,
In the final polishing step 1, polishing is performed using the polishing liquid composition of the present disclosure,
The final polishing step 2 relates to a method of polishing a silicon substrate, in which polishing is performed using a polishing liquid composition containing silica particles and a water-soluble polymer.
The polishing conditions for the final polishing steps 1 and 2 include the same polishing conditions as in the polishing step in the polishing method of the present disclosure described above.
The final polishing step 1 and the final polishing step 2 can be performed using one polishing surface plate (the same polishing surface plate). Alternatively, the final polishing process 1 and the final polishing process 2 may be performed using different polishing plates, that is, the final polishing process 2 may be performed on a polishing plate that is different from the polishing plate used in the final polishing process 1. can.
[半導体基板の製造方法]
本開示は、一態様において、本開示の研磨方法を行うことを含む、半導体基板の製造方法(以下、「本開示の半導体基板製造方法」ともいう)に関する。本開示の半導体基板製造方法は、一又は複数の実施形態において、本開示の研磨液組成物を用いて被研磨シリコン基板を研磨する工程(以下、「研磨工程」ともいう)と、研磨されたシリコン基板を洗浄する工程(以下、「洗浄工程」ともいう)と、を含むことができる。
本開示の半導体基板製造方法によれば、本開示の研磨液組成物を用いることで、研磨速度向上と濃縮物の保存安定性とを両立できるため、高品質の半導体基板を高収率で、生産性よく、安価に製造できる。
[Method for manufacturing semiconductor substrate]
In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate (hereinafter also referred to as "the semiconductor substrate manufacturing method of the present disclosure"), which includes performing the polishing method of the present disclosure. In one or more embodiments, the semiconductor substrate manufacturing method of the present disclosure includes a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure (hereinafter also referred to as a "polishing step"), The method may include a step of cleaning the silicon substrate (hereinafter also referred to as a "cleaning step").
According to the semiconductor substrate manufacturing method of the present disclosure, by using the polishing liquid composition of the present disclosure, it is possible to achieve both an improvement in polishing rate and storage stability of the concentrate, so that high quality semiconductor substrates can be produced at a high yield. It can be manufactured with good productivity and at low cost.
本開示の半導体基板製造方法における研磨工程は、例えば、単結晶シリコンインゴットを薄円板状にスライスすることにより得られた単結晶シリコン基板を平面化するラッピング(粗研磨)工程と、ラッピング単結晶されたシリコン基板をエッチングした後、単結晶シリコン基板表面を鏡面化する仕上げ研磨工程とを含むことができる。本開示の研磨液組成物は、研磨速度の向上と表面品質の向上とを両立する観点から、一又は複数の実施形態において、上記仕上げ研磨工程で用いられるとことが好ましい。 The polishing step in the semiconductor substrate manufacturing method of the present disclosure includes, for example, a lapping (rough polishing) step of planarizing a single crystal silicon substrate obtained by slicing a single crystal silicon ingot into thin disk shapes, and After etching the silicon substrate, the method may include a final polishing step of mirror-finishing the surface of the single-crystal silicon substrate. The polishing liquid composition of the present disclosure is preferably used in the final polishing step in one or more embodiments from the viewpoint of both improving the polishing rate and improving the surface quality.
本開示の半導体基板製造方法における研磨工程は、例えば、二酸化ケイ素膜及び窒化ケイ素膜を有するシリコン基板の上に化学蒸着(CVD)法によりポリシリコン膜を製膜した基板をポリシリコン膜の凹凸を除去して平坦化する工程と、直下の二酸化ケイ素膜及び窒化ケイ素膜とポリシリコン膜とを同時に研磨し平坦化する工程とを含むことができる。本開示の研磨液組成物は、研磨速度の向上と表面品質の向上とを両立する観点から、上記ポリシリコン膜の凹凸を除去して平坦化する工程で用いられるとより好ましい。 In the polishing step in the semiconductor substrate manufacturing method of the present disclosure, for example, a substrate in which a polysilicon film is formed by a chemical vapor deposition (CVD) method on a silicon substrate having a silicon dioxide film and a silicon nitride film is polished. It can include a step of removing and planarizing, and a step of simultaneously polishing and planarizing the silicon dioxide film, silicon nitride film, and polysilicon film immediately below. The polishing liquid composition of the present disclosure is more preferably used in the process of removing the unevenness of the polysilicon film and flattening it, from the viewpoint of both improving the polishing rate and improving the surface quality.
本開示の半導体基板製造方法における研磨工程は、上述した本開示の研磨方法における研磨工程と同様の条件(研磨圧力、研磨液組成物及び研磨パッドの表面温度等)で研磨を行うことができる。 The polishing step in the semiconductor substrate manufacturing method of the present disclosure can be performed under the same conditions (polishing pressure, polishing liquid composition, surface temperature of the polishing pad, etc.) as the polishing step in the polishing method of the present disclosure described above.
本開示の半導体基板製造方法は、一又は複数の実施形態において、前記研磨工程の前に、本開示の研磨液組成物の濃縮物を希釈する希釈工程を含んでいてもよい。希釈媒には、例えば、水を用いることができる。 In one or more embodiments, the semiconductor substrate manufacturing method of the present disclosure may include a dilution step of diluting the concentrate of the polishing liquid composition of the present disclosure before the polishing step. For example, water can be used as the diluent.
本開示の半導体基板製造方法における洗浄工程では、シリコン基板表面上の残留物低減の観点から、無機物洗浄を行うことが好ましい。無機物洗浄で用いる洗浄剤としては、例えば、過酸化水素、アンモニア、塩酸、硫酸、フッ酸及びオゾン水から選ばれる少なくとも1種を含む無機物洗浄剤が挙げられる。 In the cleaning step in the semiconductor substrate manufacturing method of the present disclosure, inorganic cleaning is preferably performed from the viewpoint of reducing residue on the silicon substrate surface. Examples of the cleaning agent used in inorganic cleaning include inorganic cleaning agents containing at least one selected from hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, hydrofluoric acid, and ozone water.
本開示の半導体基板製造方法は、一又は複数の実施形態において、前記洗浄工程の後に、洗浄後のシリコン基板を水でリンスし、乾燥する工程を更に含むことができる。 In one or more embodiments, the semiconductor substrate manufacturing method of the present disclosure can further include, after the cleaning step, a step of rinsing the cleaned silicon substrate with water and drying it.
本開示の半導体基板製造方法における研磨工程は、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点から、仕上げ研磨工程であることが好ましい。
本開示の半導体基板製造方法における研磨工程は、一又は複数の実施形態において、研磨速度の向上と濃縮物の保存安定性とを両立する観点、及び、表面品質の向上の観点から、仕上げ研磨工程の前段階にあたる研磨工程であることが好ましい。仕上げ研磨工程の前段階にあたる研磨工程は、一又は複数の実施形態において、上述した本開示の研磨方法における仕上げ研磨工程1が挙げられる。
In one or more embodiments, the polishing step in the semiconductor substrate manufacturing method of the present disclosure is preferably a final polishing step from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate.
In one or more embodiments, the polishing step in the semiconductor substrate manufacturing method of the present disclosure is a final polishing step from the viewpoint of achieving both improvement in polishing rate and storage stability of the concentrate, and from the viewpoint of improving surface quality. It is preferable that the polishing step is a preceding step. In one or more embodiments, the polishing step that is a pre-stage of the final polishing step includes the final polishing step 1 in the polishing method of the present disclosure described above.
本開示の半導体基板製造方法における研磨工程が、上述した仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われる研磨工程である場合、仕上げ研磨工程1及び2は、上述した本開示の研磨方法における仕上げ研磨工程1及び2と同様の条件(研磨圧力、研磨液組成物及び研磨パッドの表面温度等)で研磨を行うことができる。 When the polishing step in the semiconductor substrate manufacturing method of the present disclosure is a polishing step in which the above-described final polishing step 1 and final polishing step 2 are performed in this order, the final polishing steps 1 and 2 are the polishing steps of the present disclosure. Polishing can be performed under the same conditions (polishing pressure, polishing liquid composition, surface temperature of the polishing pad, etc.) as in the final polishing steps 1 and 2 in the method.
本開示の半導体基板製造方法における研磨工程が、上述した仕上げ研磨工程1と仕上げ研磨工程2とがこの順で行われる研磨工程である場合、仕上げ研磨工程1を行った後、洗浄、乾燥を行い、仕上げ研磨工程2を行ってもよい。また、仕上げ研磨工程1を行った後、洗浄、乾燥を行なわずに、仕上げ研磨工程2を行ってもよい。生産性向上の観点から、仕上げ研磨工程1を行った後、洗浄、乾燥を行なわずに、仕上げ研磨工程2を行うことが好ましい。 When the polishing step in the semiconductor substrate manufacturing method of the present disclosure is a polishing step in which the above-mentioned final polishing step 1 and final polishing step 2 are performed in this order, cleaning and drying are performed after performing the final polishing step 1. , a final polishing step 2 may be performed. Further, after performing the final polishing step 1, the final polishing step 2 may be performed without cleaning and drying. From the viewpoint of improving productivity, after performing the final polishing step 1, it is preferable to perform the final polishing step 2 without washing or drying.
以下、実施例により本開示をさらに詳細に説明するが、これらは例示的なものであって、本開示はこれら実施例に制限されるものではない。 Hereinafter, the present disclosure will be explained in more detail with reference to Examples, but these are merely illustrative and the present disclosure is not limited to these Examples.
1.研磨液組成物の調製(実施例1~3、比較例1~2)
(研磨液組成物の濃縮物)
表1に示すシリカ粒子(成分A)、表1に示す水溶性高分子(成分B又は非成分B)、及び超純水を撹拌混合して、研磨液組成物の濃縮物(20倍)を得た。pH調整には、アンモニア(成分C)を適量用いた。濃縮物の25℃におけるpH9.6~10.5であった。
(研磨液組成物)
上記濃縮物をイオン交換水で20倍希釈して、実施例1~3及び比較例1~2の研磨液組成物を得た。
表1の各成分の含有量は、希釈後の研磨液組成物の使用時における各成分の含有量(質量%、有効分)である。超純水の含有量は、成分Aと成分B又は非成分Bと成分Cとを除いた残余である。各研磨液組成物(使用時)の25℃におけるpHは表1に示す値であった。
1. Preparation of polishing liquid composition (Examples 1 to 3, Comparative Examples 1 to 2)
(Concentrate of polishing liquid composition)
The silica particles (component A) shown in Table 1, the water-soluble polymer (component B or non-component B) shown in Table 1, and ultrapure water are stirred and mixed to form a concentrate (20 times) of the polishing liquid composition. Obtained. An appropriate amount of ammonia (component C) was used for pH adjustment. The pH of the concentrate at 25°C was 9.6-10.5.
(Polishing liquid composition)
The above concentrate was diluted 20 times with ion-exchanged water to obtain polishing liquid compositions of Examples 1 to 3 and Comparative Examples 1 and 2.
The content of each component in Table 1 is the content (% by mass, effective content) of each component when the diluted polishing liquid composition is used. The content of ultrapure water is the remainder after removing component A and component B or non-component B and component C. The pH of each polishing liquid composition (when used) at 25° C. was the value shown in Table 1.
各研磨液組成物の調製に用いた成分A、成分B、非成分B及び成分Cには下記のものを用いた。
(成分A)
コロイダルシリカ[平均一次粒子径35nm、平均二次粒子径70nm、会合度2.0]
(成分B)
PO変性PEI:PО(プロピレンオキサイド)変性ポリエチレンイミン[日本触媒社製、PP-061、重量平均分子量5,000、PEIの全アミノ基中の第1級アミノ基及び第2級アミノ基の比率:0%]
(非成分B)
PEI:ポリエチレンイミン[日本触媒社製、SP-006、重量平均分子量2,000]
HEC:ヒドロキシエチルセルロース[ダイセル社製、SE-400、重量平均分子量250,000]
(成分C)
アンモニア[28質量%アンモニア水、キシダ化学社製、試薬特級]
The following components were used as component A, component B, non-component B, and component C used to prepare each polishing liquid composition.
(Component A)
Colloidal silica [average primary particle diameter 35 nm, average secondary particle diameter 70 nm, degree of association 2.0]
(Component B)
PO-modified PEI: PO (propylene oxide)-modified polyethyleneimine [manufactured by Nippon Shokubai Co., Ltd., PP-061, weight average molecular weight 5,000, ratio of primary amino groups and secondary amino groups in the total amino groups of PEI: 0%]
(Non-ingredient B)
PEI: Polyethyleneimine [manufactured by Nippon Shokubai Co., Ltd., SP-006, weight average molecular weight 2,000]
HEC: Hydroxyethylcellulose [manufactured by Daicel, SE-400, weight average molecular weight 250,000]
(Component C)
Ammonia [28% by mass ammonia water, manufactured by Kishida Chemical Co., Ltd., special reagent grade]
2.各種パラメータの測定方法
(1)シリカ粒子(成分A)の平均一次粒子径の測定
成分Aの平均一次粒子径(nm)は、BET(窒素吸着)法によって算出される比表面積S(m2/g)を用いて下記式で算出した。
平均一次粒子径(nm)=2727/S
2. Methods for measuring various parameters (1) Measurement of average primary particle diameter of silica particles (component A) The average primary particle diameter (nm) of component A is the specific surface area S (m 2 / g) using the following formula.
Average primary particle diameter (nm) = 2727/S
成分Aの比表面積Sは、下記の[前処理]をした後、測定サンプル約0.1gを測定セルに小数点以下4桁まで精量し、比表面積の測定直前に110℃の雰囲気下で30分間乾燥した後、比表面積測定装置(マイクロメリティック自動比表面積測定装置「フローソーブIII2305」、島津製作所製)を用いて窒素吸着法(BET法)により測定した。
[前処理]
(a)スラリー状の成分Aを硝酸水溶液でpH2.5±0.1に調整する。
(b)pH2.5±0.1に調整されたスラリー状の成分Aをシャーレにとり150℃の熱風乾燥機内で1時間乾燥させる。
(c)乾燥後、得られた試料をメノウ乳鉢で細かく粉砕する。
(d)粉砕された試料を40℃のイオン交換水に懸濁させ、孔径1μmのメンブランフィルタで濾過する。
(e)フィルタ上の濾過物を20gのイオン交換水(40℃)で5回洗浄する。
(f)濾過物が付着したフィルタをシャーレにとり、110℃の雰囲気下で4時間乾燥させる。
(g)乾燥した濾過物(成分A)をフィルタ屑が混入しないようにとり、乳鉢で細かく粉砕して測定サンプルを得た。
The specific surface area S of component A is calculated by weighing approximately 0.1 g of a measurement sample into a measurement cell to four decimal places after the following [pretreatment], and heating it at 30°C in an atmosphere of 110°C immediately before measuring the specific surface area. After drying for a minute, measurement was performed by a nitrogen adsorption method (BET method) using a specific surface area measuring device (Micromeritic automatic specific surface area measuring device "Flowsorb III 2305", manufactured by Shimadzu Corporation).
[Preprocessing]
(a) Component A in slurry form is adjusted to pH 2.5±0.1 with an aqueous nitric acid solution.
(b) Component A in the form of slurry adjusted to pH 2.5±0.1 is placed in a Petri dish and dried in a hot air dryer at 150° C. for 1 hour.
(c) After drying, the obtained sample is finely ground in an agate mortar.
(d) The pulverized sample is suspended in ion-exchanged water at 40°C and filtered through a membrane filter with a pore size of 1 μm.
(e) Wash the filtrate on the filter 5 times with 20 g of ion-exchanged water (40°C).
(f) Take the filter with the filtrate attached to it in a petri dish and dry it in an atmosphere of 110° C. for 4 hours.
(g) The dried filtrate (component A) was taken to avoid contamination with filter debris, and finely ground in a mortar to obtain a measurement sample.
(2)シリカ粒子(成分A)の平均二次粒子径
成分Aの平均二次粒子径(nm)は、成分Aの濃度が0.5質量%となるようにシリカ粒子をイオン交換水に添加した後、得られた水分散液をDisposable Sizing Cuvette(ポリスチレン製 10mmセル)に下底からの高さ10mmまで入れ、動的光散乱法(装置名:「ゼータサイザーNano ZS」、シスメックス社製)を用いて測定した。
(2) Average secondary particle diameter of silica particles (component A) The average secondary particle diameter (nm) of component A is determined by adding silica particles to ion-exchanged water so that the concentration of component A is 0.5% by mass. After that, the obtained aqueous dispersion was placed in a Disposable Sizing Cuvette (polystyrene 10 mm cell) to a height of 10 mm from the bottom, and subjected to dynamic light scattering method (device name: "Zetasizer Nano ZS", manufactured by Sysmex Corporation). Measured using
(3)水溶性高分子の重量平均分子量の測定
水溶性高分子の重量平均分子量は、ゲルパーミエーションクロマトグラフィー(GPC)法を下記の条件で適用して得たクロマトグラム中のピークに基づき算出した。
<水溶性高分子の測定条件>
装置:HLC-8320 GPC(東ソー社製、検出器一体型)
カラム:α-M+α-M
溶離液:0.15mol/L Na2SO4,1%CH3COOH/水
流量:1.0mL/min
カラム温度:40℃
検出器:ショーデックスRI SE-61示差屈折率検出器
標準物質:分子量が既知の単分散ポリエチレングリコール
(3) Measurement of weight average molecular weight of water-soluble polymer The weight average molecular weight of water-soluble polymer is calculated based on the peak in the chromatogram obtained by applying gel permeation chromatography (GPC) method under the following conditions. did.
<Measurement conditions for water-soluble polymers>
Equipment: HLC-8320 GPC (manufactured by Tosoh Corporation, integrated detector)
Column: α-M+α-M
Eluent: 0.15 mol/L Na 2 SO 4 , 1% CH 3 COOH/water flow rate: 1.0 mL/min
Column temperature: 40℃
Detector: Shodex RI SE-61 differential refractive index detector Standard material: Monodisperse polyethylene glycol with known molecular weight
(4)成分Bの全アミノ基中の第1級アミノ基及び第2級アミノ基の比率
成分Bの全アミノ基中の第1級アミノ基及び第2級アミノ基の比率は、13C-NMRを用いて求めた。
<測定条件>
試料:PO変性PEI 200mgを重水0.6mLに溶解
使用装置: 400MHz 13C-NMR(アジレント・テクノロジー株式会社製「Agilent 400-MR DD2」)
測定条件:13C-NMR測定、パルス間隔時間5秒、テトラメチルシランを標準ピーク(σ:0.0ppm)として測定
積算回数:5000回
積分に用いる各ピーク範囲:
A:39.0~42.0ppm(1級アミンのピークの積分値)
B:47.0~52.0ppm(2級アミンのピークの積分値)
C:53.0~58.0ppm(3級アミンのピークの積分値)
<全アミノ基中の第1級アミノ基及び第2級アミノ基の比率>
全アミノ基中の第1級アミノ基及び第2級アミノ基の比率は以下の式で求める。
全アミノ基中の第1級アミノ基及び第2級アミノ基の比率(当量比)= (A+B)/(A+B+C)
(4) Ratio of primary amino groups and secondary amino groups in all amino groups of component B The ratio of primary amino groups and secondary amino groups in all amino groups of component B is determined by 13C-NMR. It was calculated using
<Measurement conditions>
Sample: 200 mg of PO modified PEI dissolved in 0.6 mL of heavy water Equipment used: 400 MHz 13C-NMR (“Agilent 400-MR DD2” manufactured by Agilent Technologies, Inc.)
Measurement conditions: 13C-NMR measurement, pulse interval time 5 seconds, tetramethylsilane as standard peak (σ: 0.0 ppm) Number of measurement integrations: 5000 Each peak range used for integration:
A: 39.0 to 42.0 ppm (integral value of primary amine peak)
B: 47.0 to 52.0 ppm (integral value of secondary amine peak)
C: 53.0 to 58.0 ppm (integral value of tertiary amine peak)
<Ratio of primary amino groups and secondary amino groups in all amino groups>
The ratio of primary amino groups and secondary amino groups in all amino groups is determined by the following formula.
Ratio (equivalence ratio) of primary amino groups and secondary amino groups in all amino groups = (A+B)/(A+B+C)
(5)研磨液組成物のpH
25℃におけるpHは、pHメータ(東亜電波工業株式会社、HM-30G)を用いて測定した値であり、pHメータの電極を研磨液組成物又はその濃縮物へ浸漬して1分後の数値である。
(5) pH of polishing liquid composition
The pH at 25°C is the value measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and the value is the value 1 minute after immersing the electrode of the pH meter in the polishing liquid composition or its concentrate. It is.
3.実施例1~3及び比較例1~2の研磨液組成物の評価
(1)研磨方法等
各研磨液組成物について、下記の研磨条件で下記のシリコン基板に対して仕上げ研磨及び洗浄を行った。
<被研磨シリコン基板>
単結晶シリコン基板[直径200mmのシリコン片面鏡面基板、伝導型:P、結晶方位:100、抵抗率:0.1Ω・cm以上100Ω・cm未満]
上記単結晶シリコン基板を市販の研磨液組成物(フジミインコーポレーテッド製、GLANZOX 1302)を用いて予め粗研磨を実施した。粗研磨を終了し仕上げ研磨に供した単結晶シリコン基板のヘイズは、2~3ppmであった。
3. Evaluation of polishing liquid compositions of Examples 1 to 3 and Comparative Examples 1 to 2 (1) Polishing method, etc. For each polishing liquid composition, final polishing and cleaning were performed on the following silicon substrates under the following polishing conditions. .
<Silicon substrate to be polished>
Single-crystal silicon substrate [silicon single-sided mirror substrate with a diameter of 200 mm, conductivity type: P, crystal orientation: 100, resistivity: 0.1 Ω·cm or more and less than 100 Ω·cm]
The single-crystal silicon substrate was roughly polished in advance using a commercially available polishing composition (GLANZOX 1302, manufactured by Fujimi Incorporated). The haze of the single crystal silicon substrate subjected to final polishing after rough polishing was 2 to 3 ppm.
<仕上げ研磨条件>
研磨機:片面8インチ研磨機「GRIND-X SPP600s」(岡本工作製)
研磨パッド:スエードパッド(東レ コーテックス社製、アスカー硬度:64、厚さ:1.37mm、ナップ長:450um、開口径:60um)
シリコン基板研磨圧力:100g/cm2
定盤回転速度:60rpm
研磨時間:5分
研磨液組成物の供給速度:150g/min
研磨液組成物の温度:23℃
キャリア回転速度:62rpm
<Final polishing conditions>
Grinding machine: Single-sided 8-inch grinding machine "GRIND-X SPP600s" (manufactured by Okamoto Kosaku)
Polishing pad: Suede pad (manufactured by Toray Cortex, Asker hardness: 64, thickness: 1.37mm, nap length: 450um, opening diameter: 60um)
Silicon substrate polishing pressure: 100g/cm 2
Surface plate rotation speed: 60 rpm
Polishing time: 5 minutes Supply rate of polishing liquid composition: 150g/min
Temperature of polishing liquid composition: 23°C
Carrier rotation speed: 62rpm
<シリコン基板の表面粗さ(ヘイズ)の測定>
表面粗さ測定装置「Surfscan SP1-DLS」(KLA Tencor社製)を用いて測定される、暗視野ワイド斜入射チャンネル(DWO)での値(DWOヘイズ)を用いた。
<Measurement of surface roughness (haze) of silicon substrate>
A value (DWO haze) in a dark field wide oblique incidence channel (DWO) measured using a surface roughness measuring device "Surfscan SP1-DLS" (manufactured by KLA Tencor) was used.
<洗浄方法>
仕上げ研磨後、シリコン基板に対して、オゾン洗浄と希フッ酸洗浄を下記のとおり行った。オゾン洗浄では、20ppmのオゾンを含んだ水溶液をノズルから流速1L/min、600rpmで回転するシリコン基板の中央に向かって3分間噴射した。このときオゾン水の温度は常温とした。次に希フッ酸洗浄を行った。希フッ酸洗浄では、0.5質量%のフッ化水素アンモニウム(特級、ナカライテクス株式会社)を含んだ水溶液をノズルから流速1L/min、600rpmで回転するシリコン基板の中央に向かって6秒間噴射した。上記オゾン洗浄と希フッ酸洗浄を1セットとして計2セット行い、最後にスピン乾燥を行った。スピン乾燥では1,500rpmでシリコン基板を回転させた。
<Washing method>
After final polishing, the silicon substrate was subjected to ozone cleaning and dilute hydrofluoric acid cleaning as described below. In ozone cleaning, an aqueous solution containing 20 ppm of ozone was sprayed from a nozzle at a flow rate of 1 L/min toward the center of the silicon substrate rotating at 600 rpm for 3 minutes. At this time, the temperature of the ozonated water was set to room temperature. Next, dilute hydrofluoric acid cleaning was performed. In dilute hydrofluoric acid cleaning, an aqueous solution containing 0.5% by mass of ammonium hydrogen fluoride (special grade, Nacalai Techs Co., Ltd.) is sprayed from a nozzle at a flow rate of 1 L/min toward the center of the silicon substrate rotating at 600 rpm for 6 seconds. did. A total of two sets of the above ozone cleaning and dilute hydrofluoric acid cleaning were performed as one set, and finally spin drying was performed. In spin drying, the silicon substrate was rotated at 1,500 rpm.
(2)研磨速度の評価
研磨前後の各シリコン基板の重さを精密天秤(Sartorius社製「BP-210S」)を用いて測定し、得られた重量差をシリコン基板の密度、面積及び研磨時間で除して、単位時間当たりの片面研磨速度を求めた。結果を、比較例2を100とした相対値として表1に示す。なお、研磨後のシリコン基板の重さとは、上記仕上げ研磨及び洗浄を行った後のシリコン基板の重さである。
(2) Evaluation of polishing speed The weight of each silicon substrate before and after polishing was measured using a precision balance (BP-210S manufactured by Sartorius), and the resulting weight difference was calculated based on the density, area, and polishing time of the silicon substrate. The single-sided polishing rate per unit time was determined. The results are shown in Table 1 as relative values with Comparative Example 2 set as 100. Note that the weight of the silicon substrate after polishing is the weight of the silicon substrate after the above-mentioned final polishing and cleaning.
(3)濃縮物の保存安定性の評価
各研磨液組成物の濃縮物100gを100mlスクリュー管に入れて密閉し、1日経過後の保存安定性を下記評価基準により評価した。研磨液組成物の濃縮物は、23℃の部屋に保管した。結果を表1に示す。
<評価基準>
A:研磨液組成物の濃縮物を調製してから1日経過後に、凝集物及び分離が生じず、分散安定性を保っているもの。
B:研磨液組成物の濃縮物を調製してから1日経過後に、凝集物及び分離が僅かに生じているもの。
C:研磨液組成物の濃縮物を調製してから1日経過後に、凝集物及び分離が生じているもの。
(3) Evaluation of storage stability of concentrate 100g of the concentrate of each polishing liquid composition was placed in a 100ml screw tube and sealed, and the storage stability after one day was evaluated according to the following evaluation criteria. The polishing liquid composition concentrate was stored in a room at 23°C. The results are shown in Table 1.
<Evaluation criteria>
A: One day after preparing the concentrate of the polishing liquid composition, no aggregates or separation occur and the dispersion stability is maintained.
B: One day after preparing the concentrate of the polishing composition, slight aggregates and separation were observed.
C: Agglomerates and separation have occurred one day after preparing the concentrate of the polishing liquid composition.
(4)シリカ粒子(成分A)の平均粒子径Da
成分Aの平均粒子径Daは、表1に示す研磨液組成物をDisposable Sizing Cuvette(ポリスチレン製10mmセル)に下底からの高さ10mmまで入れた後に、動的光散乱法(装置名:「ゼータサイザーNano ZS」、シスメックス社製)を用いて測定した。
(4) Average particle diameter Da of silica particles (component A)
The average particle diameter Da of component A was determined by applying a dynamic light scattering method (apparatus name: " The measurement was performed using a Zetasizer Nano ZS (manufactured by Sysmex Corporation).
表1に示されるように、実施例1~3の研磨液組成物は、比較例1~2の研磨液組成物に比べて、研磨速度の向上と濃縮物の保存安定性とを両立できていることが分かった。 As shown in Table 1, the polishing liquid compositions of Examples 1 to 3 were able to achieve both improved polishing speed and storage stability of the concentrate compared to the polishing liquid compositions of Comparative Examples 1 and 2. I found out that there is.
4.2段階仕上げ(多段)研磨の評価(実施例4、比較例3)
(1)(多段)連続研磨
仕上げ研磨工程1を行った後、洗浄および乾燥を行わずに、研磨機(研磨定盤)を変えて仕上げ研磨工程2を連続して行う多段研磨を行った。仕上げ研磨工程1には、表2に示す研磨液組成物(実施例1、比較例1)を用い、仕上げ研磨工程2には、下記の研磨液組成物を用いた。仕上げ研磨工程2は、上記3.の仕上げ研磨と同様の研磨条件で行った。
<仕上げ研磨工程2の研磨液組成物>
表2に示すシリカ粒子、表2に示す水溶性高分子(HEC、PEG)、及び超純水を撹拌混合して、実施例4及び比較例3の仕上げ研磨液組成物を調製した。pH調整には、アンモニアを適量使用した。調製した研磨液組成物の25℃におけるpHは10.3であった。この仕上げ研磨用組成物をそのまま仕上げ研磨工程2の研磨液として使用した。
各成分の含有量(質量%、有効分)は表2に示すとおりである。超純水の含有量は、シリカ粒子と水溶性高分子(HEC、PEG)とアンモニアとを除いた残余である。
仕上げ研磨工程2の研磨液組成物の調製に用いた各成分には下記のものを用いた。
(シリカ粒子)
コロイダルシリカ[平均一次粒子径35nm、平均二次粒子径70nm、会合度2.0]
(水溶性高分子)
HEC:ヒドロキシエチルセルロース[ダイセル社製、SE-400、重量平均分子量250,000]
PEG:ポリエチレングリコール[和光純薬工業社製、1級、重量平均分子量6,000]
(アンモニア)
アンモニア[28質量%アンモニア水、キシダ化学社製、試薬特級]
4. Evaluation of two-stage finishing (multi-stage) polishing (Example 4, Comparative Example 3)
(1) (Multi-stage) Continuous Polishing After performing the final polishing step 1, multi-stage polishing was performed in which the polishing machine (polishing surface plate) was changed and the final polishing step 2 was performed continuously without washing or drying. In the final polishing step 1, the polishing liquid composition shown in Table 2 (Example 1, Comparative Example 1) was used, and in the final polishing step 2, the following polishing liquid composition was used. Final polishing step 2 was performed under the same polishing conditions as the final polishing in 3. above.
<Polishing liquid composition for final polishing step 2>
Finish polishing liquid compositions of Example 4 and Comparative Example 3 were prepared by stirring and mixing the silica particles shown in Table 2, the water-soluble polymers (HEC, PEG) shown in Table 2, and ultrapure water. An appropriate amount of ammonia was used for pH adjustment. The pH of the prepared polishing liquid composition at 25°C was 10.3. This final polishing composition was used as it was as a polishing liquid in the final polishing step 2.
The content (mass%, effective content) of each component is as shown in Table 2. The content of ultrapure water is the remainder after removing silica particles, water-soluble polymers (HEC, PEG), and ammonia.
The following components were used to prepare the polishing liquid composition in the final polishing step 2.
(Silica particles)
Colloidal silica [average primary particle diameter 35 nm, average secondary particle diameter 70 nm, degree of association 2.0]
(Water-soluble polymer)
HEC: Hydroxyethylcellulose [manufactured by Daicel, SE-400, weight average molecular weight 250,000]
PEG: Polyethylene glycol [manufactured by Wako Pure Chemical Industries, Ltd., grade 1, weight average molecular weight 6,000]
(ammonia)
Ammonia [28% by mass ammonia water, manufactured by Kishida Chemical Co., Ltd., special reagent grade]
(2)シリコン基板の表面欠陥(LPD)の測定
上記多段研磨及び洗浄を行った後のシリコン基板の表面欠陥(LPD)を、上述と同様に測定した。結果を、比較例3を100とした相対値として表2に示す。
(2) Measurement of surface defects (LPD) of silicon substrate Surface defects (LPD) of the silicon substrate after the multi-stage polishing and cleaning were measured in the same manner as described above. The results are shown in Table 2 as relative values with Comparative Example 3 set as 100.
表2に示されるように、実施例4では、仕上げ研磨1に表1記載の実施例1の研磨液を使用することで、比較例3に比べて、仕上げ研磨工程2後の表面欠陥数(LPD)が低減されていた。 As shown in Table 2, in Example 4, the number of surface defects after final polishing step 2 ( LPD) was reduced.
本開示の研磨液組成物を用いれば、研磨速度向上と濃縮物の保存安定性とを両立できる。よって、本開示の研磨液組成物は、様々な半導体基板の製造過程で用いられる研磨液組成物として有用であり、なかでも、シリコン基板の仕上げ研磨用の研磨液組成物として有用である。 By using the polishing liquid composition of the present disclosure, it is possible to achieve both improvement in polishing rate and storage stability of the concentrate. Therefore, the polishing liquid composition of the present disclosure is useful as a polishing liquid composition used in the manufacturing process of various semiconductor substrates, and is particularly useful as a polishing liquid composition for final polishing of silicon substrates.
Claims (9)
仕上げ研磨工程1では、請求項1から6のいずれかに記載の研磨液組成物を用いて研磨し、
仕上げ研磨工程2では、シリカ粒子及び水溶性高分子を含む研磨液組成物を用いて研磨する、
シリコン基板の研磨方法。 The silicon substrate includes a final polishing step 2 for final polishing the silicon substrate, and a final polishing step 1 which is a polishing step before the final polishing step 2, and the final polishing step 1 and the final polishing step 2 are performed in this order. A method for polishing a substrate, the method comprising:
In the final polishing step 1, polishing is performed using the polishing liquid composition according to any one of claims 1 to 6,
In the final polishing step 2, polishing is performed using a polishing liquid composition containing silica particles and a water-soluble polymer.
A method for polishing silicon substrates.
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