JP6265542B2 - Manufacturing method of semiconductor substrate - Google Patents
Manufacturing method of semiconductor substrate Download PDFInfo
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- JP6265542B2 JP6265542B2 JP2014113322A JP2014113322A JP6265542B2 JP 6265542 B2 JP6265542 B2 JP 6265542B2 JP 2014113322 A JP2014113322 A JP 2014113322A JP 2014113322 A JP2014113322 A JP 2014113322A JP 6265542 B2 JP6265542 B2 JP 6265542B2
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- polishing
- silicon wafer
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- 238000004519 manufacturing process Methods 0.000 title claims description 30
- 239000004065 semiconductor Substances 0.000 title claims description 16
- 239000000758 substrate Substances 0.000 title claims description 13
- 238000005498 polishing Methods 0.000 claims description 195
- 235000012431 wafers Nutrition 0.000 claims description 126
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 118
- 229910052710 silicon Inorganic materials 0.000 claims description 118
- 239000010703 silicon Substances 0.000 claims description 118
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- 230000008569 process Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 3
- UVRCNEIYXSRHNT-UHFFFAOYSA-N 3-ethylpent-2-enamide Chemical compound CCC(CC)=CC(N)=O UVRCNEIYXSRHNT-UHFFFAOYSA-N 0.000 description 3
- WHNPOQXWAMXPTA-UHFFFAOYSA-N 3-methylbut-2-enamide Chemical compound CC(C)=CC(N)=O WHNPOQXWAMXPTA-UHFFFAOYSA-N 0.000 description 3
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- LXEKPEMOWBOYRF-UHFFFAOYSA-N [2-[(1-azaniumyl-1-imino-2-methylpropan-2-yl)diazenyl]-2-methylpropanimidoyl]azanium;dichloride Chemical compound Cl.Cl.NC(=N)C(C)(C)N=NC(C)(C)C(N)=N LXEKPEMOWBOYRF-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 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
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 description 2
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- QUSNBJAOOMFDIB-UHFFFAOYSA-N Ethylamine Chemical compound CCN QUSNBJAOOMFDIB-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
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- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 2
- GLUUGHFHXGJENI-UHFFFAOYSA-N Piperazine Chemical compound C1CNCCN1 GLUUGHFHXGJENI-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 150000005215 alkyl ethers Chemical class 0.000 description 2
- 125000005037 alkyl phenyl group Chemical group 0.000 description 2
- 239000001099 ammonium carbonate Substances 0.000 description 2
- 150000003868 ammonium compounds Chemical class 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
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- 238000002296 dynamic light scattering Methods 0.000 description 2
- 239000003480 eluent Substances 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 125000002768 hydroxyalkyl group Chemical group 0.000 description 2
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 239000008363 phosphate buffer Substances 0.000 description 2
- 239000012925 reference material Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 description 2
- 239000002699 waste material Substances 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
- VILCJCGEZXAXTO-UHFFFAOYSA-N 2,2,2-tetramine Chemical compound NCCNCCNCCN VILCJCGEZXAXTO-UHFFFAOYSA-N 0.000 description 1
- IWSZDQRGNFLMJS-UHFFFAOYSA-N 2-(dibutylamino)ethanol Chemical compound CCCCN(CCO)CCCC IWSZDQRGNFLMJS-UHFFFAOYSA-N 0.000 description 1
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 1
- URDCARMUOSMFFI-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(2-hydroxyethyl)amino]acetic acid Chemical compound OCCN(CC(O)=O)CCN(CC(O)=O)CC(O)=O URDCARMUOSMFFI-UHFFFAOYSA-N 0.000 description 1
- BFSVOASYOCHEOV-UHFFFAOYSA-N 2-diethylaminoethanol Chemical compound CCN(CC)CCO BFSVOASYOCHEOV-UHFFFAOYSA-N 0.000 description 1
- 229940100555 2-methyl-4-isothiazolin-3-one Drugs 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- 238000004438 BET method Methods 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
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 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
- 229920001214 Polysorbate 60 Polymers 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
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- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 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
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- 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
- 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
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- DXGKKTKNDBFWLL-UHFFFAOYSA-N azane;2-[bis(carboxymethyl)amino]acetic acid Chemical compound N.N.N.OC(=O)CN(CC(O)=O)CC(O)=O DXGKKTKNDBFWLL-UHFFFAOYSA-N 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
- 229960000686 benzalkonium chloride Drugs 0.000 description 1
- UREZNYTWGJKWBI-UHFFFAOYSA-M benzethonium chloride Chemical compound [Cl-].C1=CC(C(C)(C)CC(C)(C)C)=CC=C1OCCOCC[N+](C)(C)CC1=CC=CC=C1 UREZNYTWGJKWBI-UHFFFAOYSA-M 0.000 description 1
- 229960001950 benzethonium chloride Drugs 0.000 description 1
- DMSMPAJRVJJAGA-UHFFFAOYSA-N benzo[d]isothiazol-3-one Chemical compound C1=CC=C2C(=O)NSC2=C1 DMSMPAJRVJJAGA-UHFFFAOYSA-N 0.000 description 1
- CADWTSSKOVRVJC-UHFFFAOYSA-N benzyl(dimethyl)azanium;chloride Chemical compound [Cl-].C[NH+](C)CC1=CC=CC=C1 CADWTSSKOVRVJC-UHFFFAOYSA-N 0.000 description 1
- 239000004359 castor oil Substances 0.000 description 1
- 235000019438 castor oil Nutrition 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
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- 238000000354 decomposition reaction Methods 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
- 239000012897 dilution medium Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007518 final polishing process Methods 0.000 description 1
- 229910021485 fumed silica Inorganic materials 0.000 description 1
- 229920001002 functional polymer Polymers 0.000 description 1
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 description 1
- VXZOOXXSYPYWEP-UHFFFAOYSA-H hexasodium hexaacetate Chemical compound C(C)(=O)[O-].[Na+].[Na+].[Na+].[Na+].[Na+].[Na+].C(C)(=O)[O-].C(C)(=O)[O-].C(C)(=O)[O-].C(C)(=O)[O-].C(C)(=O)[O-] VXZOOXXSYPYWEP-UHFFFAOYSA-H 0.000 description 1
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- BEGLCMHJXHIJLR-UHFFFAOYSA-N methylisothiazolinone Chemical compound CN1SC=CC1=O BEGLCMHJXHIJLR-UHFFFAOYSA-N 0.000 description 1
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- 229910017604 nitric acid Inorganic materials 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 125000005702 oxyalkylene group Chemical group 0.000 description 1
- 239000003002 pH adjusting agent Substances 0.000 description 1
- 238000000206 photolithography Methods 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
- 238000007517 polishing process Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
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- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- DZCAZXAJPZCSCU-UHFFFAOYSA-K sodium nitrilotriacetate Chemical compound [Na+].[Na+].[Na+].[O-]C(=O)CN(CC([O-])=O)CC([O-])=O DZCAZXAJPZCSCU-UHFFFAOYSA-K 0.000 description 1
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- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- QEMXHQIAXOOASZ-UHFFFAOYSA-N tetramethylammonium Chemical compound C[N+](C)(C)C QEMXHQIAXOOASZ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Description
本発明は半導体基板の製造方法、及び被研磨シリコンウェーハの研磨方法に関する。 The present invention relates to a method for manufacturing a semiconductor substrate and a method for polishing a silicon wafer to be polished.
近年、半導体メモリの高記録容量化に対する要求の高まりから半導体装置のデザインルールは微細化が進んでいる。このため半導体装置の製造過程で行われるフォトリソグラフィーにおいて焦点深度は浅くなり、シリコンウェーハ（ベアウェーハ）の表面欠陥（ＬＰＤ：Light point defects）や表面粗さ（ヘイズ：Haze）の低減に対する要求はますます厳しくなっている。 In recent years, design rules for semiconductor devices have been increasingly miniaturized due to increasing demand for higher recording capacity of semiconductor memories. For this reason, the depth of focus is reduced in photolithography performed in the manufacturing process of semiconductor devices, and there is a demand for reduction of surface defects (LPD: Light point defects) and surface roughness (Haze) of silicon wafers (bare wafers). It is getting stricter.
シリコンウェーハの品質を向上する目的で、シリコンウェーハの研磨は多段階で行われている。特に研磨の最終段階で行われる仕上げ研磨は、表面粗さの低減とパーティクルやスクラッチ、ピット等の表面欠陥の低減とを目的として行われている。 In order to improve the quality of silicon wafers, polishing of silicon wafers is performed in multiple stages. In particular, finish polishing performed at the final stage of polishing is performed for the purpose of reducing surface roughness and reducing surface defects such as particles, scratches, and pits.
シリコンウェーハの研磨に用いられる研磨用組成物として、保存安定性の向上、良好な生産性が確保される研磨速度の担保、及び表面欠陥（ＬＰＤ）と表面粗さ(ヘイズ)の低減を目的とし、シリカ粒子と、窒素塩基性化合物と、ヒドロキシエチルアクリルアミド（ＨＥＡＡ）等のアクリルアミド誘導体に由来する構成単位を含む水溶性高分子化合物とを含むシリコンウェーハの研磨用組成物が開示されている（特許文献１）。また、ヘイズレベルの改善を目的とし、シリカ粒子と、ヒドロキシエチルセルロース（ＨＥＣ）と、ポリエチレンオキサイドと、アルカリ化合物とを含む研磨用組成物が開示されている（特許文献２）。また、ヘイズレベルを低下させることなくウェーハ表面に付着するパーティクルを低減することを目的とし、シリカ粒子、アンモニア等の塩基性化合物、ＨＥＣ等の水溶性高分子化合物、アルコール性水酸基を１〜１０個有する化合物を含む研磨用組成物が開示されている（特許文献３）。 As a polishing composition used for polishing silicon wafers, the purpose is to improve storage stability, ensure the polishing rate to ensure good productivity, and reduce surface defects (LPD) and surface roughness (haze). A composition for polishing a silicon wafer comprising silica particles, a nitrogen basic compound, and a water-soluble polymer compound containing a structural unit derived from an acrylamide derivative such as hydroxyethylacrylamide (HEAA) is disclosed (patent) Reference 1). Further, for the purpose of improving the haze level, a polishing composition containing silica particles, hydroxyethyl cellulose (HEC), polyethylene oxide, and an alkali compound is disclosed (Patent Document 2). In addition, for the purpose of reducing particles adhering to the wafer surface without lowering the haze level, silica particles, basic compounds such as ammonia, water-soluble polymer compounds such as HEC, and 1 to 10 alcoholic hydroxyl groups Polishing composition containing the compound which has is disclosed (patent document 3).
これらの研磨用組成物は、製造及び輸送コストを低くできる等の経済性の観点から、その保存安定性が損なわれない範囲で濃縮された状態で保存及び輸送され、必要に応じてイオン交換水等により希釈して使用されることが多い。 These polishing compositions are stored and transported in a concentrated state as long as their storage stability is not impaired, from the viewpoint of economy such that production and transportation costs can be reduced, and ion-exchanged water as necessary. In many cases, it is used after diluting.
しかし、濃縮状態の研磨用組成物を希釈してからシリコンウェーハの研磨に用いた場合、時として、研磨されたシリコンウェーハ表面の表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）の低減が不十分であった。 However, when the concentrated polishing composition is diluted and then used for polishing a silicon wafer, sometimes the surface roughness (haze) and surface defects (LPD) of the polished silicon wafer surface are insufficiently reduced. Met.
本発明では、研磨されたシリコンウェーハ表面の表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）を、安定して低減可能とする、半導体基板の製造方法及び被研磨シリコンウェーハの研磨方法を提供する。 The present invention provides a method for manufacturing a semiconductor substrate and a method for polishing a silicon wafer to be polished, which can stably reduce the surface roughness (haze) and surface defects (LPD) of the polished silicon wafer surface.
本発明の半導体基板の製造方法は、シリコンウェーハ用研磨液組成物を用いて被研磨シリコンウェーハを研磨する工程を含み、
シリコンウェーハ用研磨液組成物は、シリカ粒子、水溶性高分子化合物、及び塩基性化合物を含み、
調製後１４日以上経た前記シリコンウェーハ用研磨液組成物の濃縮液を希釈後２日以内に前記被研磨シリコンウェーハの研磨に使用し、
前記シリコンウェーハ用研磨液組成物の濃縮液を希釈して得た前記シリコンウェーハ用研磨液組成物における、前記塩基性化合物の含有量は６０質量ｐｐｍ以上３００質量ｐｐｍ以下、前記水溶性高分子化合物の含有量は６０質量ｐｐｍ以上５２０質量ｐｐｍ以下である、半導体基板の製造方法である。
The method for producing a semiconductor substrate of the present invention includes a step of polishing a silicon wafer to be polished using a polishing composition for a silicon wafer,
The polishing composition for a silicon wafer includes silica particles, a water-soluble polymer compound, and a basic compound,
Use for polishing the silicon wafer to be polished within 2 days after dilution of the concentrated solution of the polishing composition for a silicon wafer that has passed 14 days or more after preparation,
In the polishing composition for a silicon wafer obtained by diluting a concentrated solution of the polishing composition for a silicon wafer, the content of the basic compound is 60 mass ppm to 300 mass ppm, and the water-soluble polymer compound. Is a manufacturing method of a semiconductor substrate which is 60 mass ppm or more and 520 mass ppm or less.
本発明の被研磨シリコンウェーハの研磨方法は、シリコンウェーハ用研磨液組成物を用いて被研磨シリコンウェーハを研磨する工程を含み、
シリコンウェーハ用研磨液組成物は、シリカ粒子、水溶性高分子化合物、及び塩基性化合物を含み、
調製後１４日以上経た、前記シリコンウェーハ用研磨液組成物の濃縮液を、希釈後２日以内に前記被研磨シリコンウェーハの研磨に使用し、
前記シリコンウェーハ用研磨液組成物の濃縮液を希釈して得た前記シリコンウェーハ用研磨液組成物における、前記塩基性化合物の含有量は６０質量ｐｐｍ以上３００質量ｐｐｍ以下、前記水溶性高分子化合物の含有量は６０質量ｐｐｍ以上５２０質量ｐｐｍ以下である、被研磨シリコンウェーハの研磨方法である。
The method for polishing a silicon wafer to be polished according to the present invention includes a step of polishing the silicon wafer to be polished using a polishing composition for a silicon wafer,
The polishing composition for a silicon wafer includes silica particles, a water-soluble polymer compound, and a basic compound,
More than 14 days after preparation, the concentrated solution of the polishing composition for a silicon wafer is used for polishing the silicon wafer to be polished within 2 days after dilution,
In the polishing composition for a silicon wafer obtained by diluting a concentrated solution of the polishing composition for a silicon wafer, the content of the basic compound is 60 mass ppm to 300 mass ppm, and the water-soluble polymer compound. Is a polishing method for a silicon wafer to be polished, wherein the content is 60 mass ppm or more and 520 mass ppm or less.
本発明によれば、研磨されたシリコンウェーハ表面の表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）を、安定して低減可能とする、半導体基板の製造方法及び被研磨シリコンウェーハの研磨方法を提供する。 According to the present invention, there are provided a method for manufacturing a semiconductor substrate and a method for polishing a silicon wafer to be polished, which can stably reduce the surface roughness (haze) and surface defects (LPD) of the polished silicon wafer surface. To do.
シリカ粒子、塩基性化合物、及び水溶性高分子化合物を含むシリコンウェーハ用研磨液組成物（以下、単に「研磨液組成物」と言う場合もある。）を用いて被研磨シリコンウェーハを研磨する最中、水溶性高分子化合物は、シリカ粒子と被研磨シリコンウェーハの両方に吸着することができる。その為、水溶性高分子化合物は、シリカ粒子を被研磨シリコンウェーハに近づけ、表面粗さ（ヘイズ）の悪化の原因となるシリカ粒子が直接被研磨シリコンウェーハに接触することを抑制し、且つ、表面粗さ（ヘイズ）の悪化の原因となる塩基性化合物によるウェーハ表面の腐食を抑制するように作用する。故に、水溶性高分子化合物は、研磨速度の向上、研磨されたシリコンウェーハの洗浄工程におけるパーティクル（シリカ粒子や研磨くず）の脱離性向上、及び表面粗さ（ヘイズ）の低減に寄与している。パーティクルの脱離性向上は、表面欠陥（ＬＰＤ）の低減に寄与する。 A silicon wafer polishing liquid composition containing silica particles, a basic compound, and a water-soluble polymer compound (hereinafter sometimes simply referred to as “polishing liquid composition”) is used to polish a silicon wafer to be polished. Among these, the water-soluble polymer compound can be adsorbed on both the silica particles and the silicon wafer to be polished. Therefore, the water-soluble polymer compound brings the silica particles closer to the silicon wafer to be polished, suppresses the silica particles that cause deterioration of the surface roughness (haze) from directly contacting the silicon wafer to be polished, and It acts to suppress corrosion of the wafer surface due to the basic compound that causes deterioration of the surface roughness (haze). Therefore, the water-soluble polymer compound contributes to improving the polishing rate, improving the detachability of particles (silica particles and polishing waste) in the polishing process of the polished silicon wafer, and reducing the surface roughness (haze). Yes. Improvement of particle detachability contributes to reduction of surface defects (LPD).
しかし、同組成の研磨液組成物を用いても、表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）がばらつくことがあった。本発明者は、このバラツキの原因を探求した結果、調製後１４日以上経た、研磨液組成物の濃縮液を、希釈後２日以内に被研磨シリコンウェーハの研磨に使用すれば、前記研磨液組成物の性能が安定して発揮されて、シリコンウェーハ表面の表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）の低減が安定して可能となること（以下「本発明の安定化効果」という場合もある。）を見出した。 However, even when a polishing composition having the same composition is used, surface roughness (haze) and surface defects (LPD) may vary. As a result of searching for the cause of this variation, the present inventor used the concentrated liquid of the polishing liquid composition that has passed 14 days or more after preparation for polishing a silicon wafer to be polished within 2 days after dilution. The performance of the composition is stably exhibited, and the surface roughness (haze) and surface defects (LPD) of the silicon wafer surface can be stably reduced (hereinafter referred to as “the stabilization effect of the present invention”). Also found.)
表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）についてバラツキが生じる原因は明らかではないが、水溶性高分子化合物がシリカ粒子に吸着するためには前記濃縮液の調製後、所定の保存時間を必要とし、且つ、濃縮液の希釈後、所定の期間を経過すると、シリカ粒子へ水溶性高分子化合物が更に吸着して、水溶性高分子化合物のウェーハに対する上記作用が十分に発揮されないため、表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）のバラツキが生じると推察される。 The cause of the variation in surface roughness (haze) and surface defect (LPD) is not clear, but a predetermined storage time is required after preparation of the concentrated solution in order for the water-soluble polymer compound to be adsorbed on the silica particles. In addition, after a predetermined period of time has passed after dilution of the concentrate, the water-soluble polymer compound is further adsorbed onto the silica particles, and the above-described action of the water-soluble polymer compound on the wafer is not sufficiently exhibited. It is inferred that variations in thickness (haze) and surface defects (LPD) occur.
本発明の半導体基板の製造方法（以下「本発明の製造方法」と言う場合もある。）及び本発明の被研磨シリコンウェーハの研磨方法（以下「本発明の研磨方法」と言う場合もある。）は、各々、前記研磨液組成物を用いて被研磨シリコンウェーハを研磨する工程を含む。前記研磨液組成物は、シリカ粒子、水溶性高分子化合物、及び塩基性化合物を含む。 The semiconductor substrate manufacturing method of the present invention (hereinafter sometimes referred to as “the manufacturing method of the present invention”) and the silicon wafer polishing method of the present invention (hereinafter also referred to as “the polishing method of the present invention”). ) Each include a step of polishing a silicon wafer to be polished using the polishing composition. The polishing liquid composition contains silica particles, a water-soluble polymer compound, and a basic compound.
[シリカ粒子（成分Ａ）]
前記研磨液組成物には、研磨材としてシリカ粒子（成分Ａ）が含まれる。シリカ粒子の具体例としては、コロイダルシリカ、フュームドシリカ等が挙げられるが、シリコンウェーハの表面平滑性を向上させる観点から、コロイダルシリカがより好ましい。
[Silica particles (component A)]
The polishing composition contains silica particles (component A) as an abrasive. Specific examples of the silica particles include colloidal silica and fumed silica. Colloidal silica is more preferable from the viewpoint of improving the surface smoothness of the silicon wafer.
シリカ粒子（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。本発明の製造方法及び本発明の研磨方法に含まれる研磨材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ウェーハ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。 The usage form of the silica particles (component A) is preferably a slurry from the viewpoint of operability. When the abrasive contained in the production method of the present invention and the polishing method of the present invention is colloidal silica, from the viewpoint of preventing contamination of the silicon wafer by alkali metal, alkaline earth metal, etc., colloidal silica is a hydrolyzed alkoxysilane. It is preferable that the product is obtained from a decomposition product. Silica particles obtained from the hydrolyzate of alkoxysilane can be produced by a conventionally known method.
前記研磨液組成物に含まれるシリカ粒子（成分Ａ）の平均一次粒子径は、本発明の安定化効果の観点から特に拘らないが、研磨速度の確保の観点から、好ましくは５ｎｍ以上、より好ましくは１０ｎｍ以上、更に好ましくは１５ｎｍ以上であり、更により好ましくは２０ｎｍ以上である。また、研磨速度の確保及び表面欠陥（ＬＰＤ）の低減との両立の観点から、好ましくは５０ｎｍ以下、より好ましくは４５ｎｍ以下、更に好ましくは４０ｎｍ以下である。 The average primary particle diameter of the silica particles (component A) contained in the polishing composition is not particularly limited from the viewpoint of the stabilizing effect of the present invention, but is preferably 5 nm or more, more preferably from the viewpoint of securing the polishing rate. Is 10 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. In addition, from the viewpoint of ensuring the polishing rate and reducing surface defects (LPD), the thickness is preferably 50 nm or less, more preferably 45 nm or less, and even more preferably 40 nm or less.
特に、シリカ粒子（成分Ａ）としてコロイダルシリカを用いた場合には、研磨速度の確保及びシリコンウェーハの表面欠陥（ＬＰＤ）の低減の観点から、平均一次粒子径は、好ましくは５ｎｍ以上、より好ましくは１０ｎｍ以上、更に好ましくは１５ｎｍ以上、更により好ましくは２０ｎｍ以上であり、また、好ましくは５０ｎｍ以下、より好ましくは４５ｎｍ以下、更に好ましくは４０ｎｍ以下である。 In particular, when colloidal silica is used as the silica particles (component A), the average primary particle diameter is preferably 5 nm or more, more preferably, from the viewpoint of securing the polishing rate and reducing the surface defects (LPD) of the silicon wafer. Is 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, and preferably 50 nm or less, more preferably 45 nm or less, still more preferably 40 nm or less.
シリカ粒子の平均一次粒子径は、ＢＥＴ（窒素吸着）法によって算出される比表面積Ｓ（ｍ2／ｇ）を用いて算出される。比表面積は、例えば、実施例に記載の方法により測定できる。 The average primary particle diameter of the silica particles is calculated using a specific surface area S (m 2 / g) calculated by a BET (nitrogen adsorption) method. A specific surface area can be measured by the method as described in an Example, for example.
シリカ粒子の会合度は、研磨速度の確保及びシリコンウェーハの表面欠陥の低減の観点から、３．０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、また、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。シリカ粒子の形状はいわゆる球型といわゆるマユ型であることが好ましい。シリカ粒子がコロイダルシリカである場合、その会合度は、研磨速度の確保及び表面欠陥の低減の観点から、３．０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、また、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 the silica particles is preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.3 or less, from the viewpoint of ensuring the polishing rate and reducing the surface defects of the silicon wafer. 1 or more is preferable, 1.5 or more is more preferable, and 1.8 or more is still more preferable. The shape of the silica particles is preferably a so-called spherical type and a so-called mayu type. When the silica particles are colloidal silica, the degree of association is preferably 3.0 or less, more preferably 2.5 or less, and even more preferably 2.3 or less, from the viewpoint of ensuring the polishing rate and reducing surface defects. Moreover, 1.1 or more are preferable, 1.5 or more are more preferable, and 1.8 or more are still more preferable.
シリカ粒子の会合度とは、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。平均二次粒子径は、動的光散乱法によって測定される値であり、例えば、実施例に記載の装置を用いて測定できる。
会合度＝平均二次粒子径／平均一次粒子径
The association degree of silica particles is a coefficient representing the shape of silica particles, and is calculated by the following formula. The average secondary particle diameter is a value measured by a dynamic light scattering method, and can be measured using, for example, the apparatus described in the examples.
Degree of association = average secondary particle size / average primary particle size
シリカ粒子の会合度の調整方法としては、特に限定されないが、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。 The method for adjusting the degree of association of the silica particles is not particularly limited. For example, JP-A-6-254383, JP-A-11-214338, JP-A-11-60232, JP-A-2005-060217, A method described in JP-A-2005-060219 or the like can be employed.
前記研磨液組成物の濃縮液に含まれるシリカ粒子（成分Ａ）の含有量は、製造及び輸送コストを低くできる等の経済性の観点から、１００００質量ｐｐｍ以上が好ましく、より好ましくは３００００質量ｐｐｍ以上、更に好ましくは４００００質量ｐｐｍ以上である。また、濃縮液中におけるシリカ粒子の含有量は、保存安定性を向上させる観点から、４０００００質量ｐｐｍ以下が好ましく、より好ましくは１０００００質量ｐｐｍ以下、更に好ましくは８００００質量ｐｐｍ以下である。 The content of the silica particles (component A) contained in the concentrated liquid of the polishing composition is preferably 10,000 ppm by mass or more, more preferably 30000 ppm by mass, from the viewpoint of economy such that production and transportation costs can be reduced. As mentioned above, More preferably, it is 40000 mass ppm or more. Further, the content of silica particles in the concentrate is preferably 400,000 ppm or less, more preferably 100,000 ppm or less, and even more preferably 80,000 ppm by weight, from the viewpoint of improving storage stability.
［水溶性高分子化合物（成分Ｂ）］
本発明の製造方法及び本発明の研磨方法で使用される研磨液組成物に含まれる水溶性高分子化合物（成分Ｂ）は、研磨速度の確保、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、例えば、下記一般式（１）で表される構成単位Ｉを７５質量％以上含む水溶性高分子化合物Ａ、又はヒドロキシエチルセルロース（ＨＥＣ）を含有する。ただし、下記一般式（１）において、Ｒ1は炭素数１〜２のヒドロキシアルキル基である。ヒドロキシエチルセルロース（ＨＥＣ）及び水溶性高分子化合物Ａのうち、シリコンウェーハの表面粗さ（ヘイズ）の低減の観点から、ＨＥＣがより好ましい。
The water-soluble polymer compound (component B) contained in the polishing liquid composition used in the production method of the present invention and the polishing method of the present invention ensures the polishing rate, surface defects (LPD) and surface roughness of the silicon wafer. From the viewpoint of reducing (haze), for example, it contains water-soluble polymer compound A containing 75% by mass or more of structural unit I represented by the following general formula (1) or hydroxyethyl cellulose (HEC). However, in the following general formula (1), R 1 is a hydroxyalkyl group having 1 to 2 carbon atoms. Of the hydroxyethyl cellulose (HEC) and the water-soluble polymer compound A, HEC is more preferable from the viewpoint of reducing the surface roughness (haze) of the silicon wafer.
本発明の製造方法及び本発明の研磨方法で使用される水溶性高分子化合物（成分Ｂ）は、本発明の研磨実施濃度領域において溶解していれば特に溶解度は限定されないが、本発明において、水溶性高分子化合物の「水溶性」とは、水に対して０．５ｇ／１００ｍｌ以上の溶解度を有することをいい、好ましくは２ｇ／１００ｍｌ以上の溶解度を有することをいう。 The solubility of the water-soluble polymer compound (component B) used in the production method of the present invention and the polishing method of the present invention is not particularly limited as long as it is dissolved in the polishing concentration range of the present invention. The “water-soluble” of the water-soluble polymer compound means having a solubility of 0.5 g / 100 ml or more in water, preferably having a solubility of 2 g / 100 ml or more.
＜水溶性高分子化合物Ａ＞
本発明の製造方法及び本発明の研磨方法で使用される研磨液組成物に含まれる水溶性高分子化合物（成分Ｂ）の一例である水溶性高分子化合物Ａについて、「構成単位Ｉを７５質量％以上含む」とは、水溶性高分子化合物Ａの１分子中における前記構成単位Ｉの質量が、水溶性高分子化合物Ａの重量平均分子量（Ｍｗ）の７５％以上であることを意味する。また、本明細書において、水溶性高分子化合物Ａを構成する全構成単位中に占める構成単位Ｉの含有量（質量％）として、合成条件によっては、水溶性高分子化合物の合成の全工程で反応槽に仕込まれた全構成単位を導入するための化合物中に占める前記反応槽に仕込まれた該構成単位Ｉを導入するための化合物量（質量％）から計算される値を使用してもよい。
<Water-soluble polymer compound A>
About the water-soluble polymer compound A which is an example of the water-soluble polymer compound (component B) contained in the polishing liquid composition used in the production method of the present invention and the polishing method of the present invention, “structural unit I is 75 mass. “Containing% or more” means that the mass of the structural unit I in one molecule of the water-soluble polymer compound A is 75% or more of the weight average molecular weight (Mw) of the water-soluble polymer compound A. Moreover, in this specification, as content (mass%) of the structural unit I which occupies in all the structural units which comprise the water-soluble polymer compound A, depending on synthesis conditions, in all the processes of the synthesis | combination of a water-soluble polymer compound. Even if the value calculated from the amount (% by mass) of the compound for introducing the structural unit I charged in the reaction tank in the compound for introducing all the structural units charged in the reaction tank is used. Good.
研磨速度の確保、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、上記一般式(１)において、Ｒ1は、炭素数１〜２のヒドロキシアルキル基であり、より好ましくはヒドロキシエチル基である。 From the viewpoint of ensuring the polishing rate and reducing the surface defects (LPD) and surface roughness (haze) of the silicon wafer, in the general formula (1), R 1 is a hydroxyalkyl group having 1 to 2 carbon atoms, More preferred is a hydroxyethyl group.
一般式（１）で表される構成単位Ｉの供給源である単量体としては、Ｎ−ヒドロキシエチルアクリルアミド（ＨＥＡＡ）またはＮ−ヒドロキシメチルアクリルアミド（ＨＭＡＡ）等のアクリルアミド誘導体であるが、これらは、１種単独または２種以上組み合わせて用いることができる。これらの単量体のなかでも、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、ＨＥＡＡが好ましい。 The monomer that is the supply source of the structural unit I represented by the general formula (1) is an acrylamide derivative such as N-hydroxyethylacrylamide (HEAA) or N-hydroxymethylacrylamide (HMAA). These can be used singly or in combination of two or more. Among these monomers, HEAA is preferable from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer.
水溶性高分子化合物Ａの全構成単位中における前記構成単位Ｉの割合は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、７５質量％以上であり、８０質量％以上が好ましく、９０質量％以上がより好ましく、実質的に１００質量％が更に好ましく、１００質量％が更により好ましい。 The proportion of the structural unit I in all the structural units of the water-soluble polymer compound A is 75% by mass or more and 80% by mass from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. % Or more, more preferably 90% by weight or more, substantially more preferably 100% by weight, and even more preferably 100% by weight.
水溶性高分子化合物Ａは、本発明の効果が奏される限りにおいて、前記構成単位Ｉ以外の構成単位を含んでいてもよい。構成単位Ｉ以外の構成単位（「構成単位II」ともいう。）を含む場合には、構成単位Ｉ以外の構成単位は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、Ｎ−イソプロピルアクリルアミド（ＮＩＰＡＭ）、アクリル酸（ＡＡ）、メタクリル酸（ＭＡＡ）、ビニルピロリドン（ＶＰ）、ジメチルアクリルアミド（ＤＭＡＡ）及びジエチルアクリルアミド(ＤＥＡＡ)からなる群から選ばれる少なくとも一種のモノマーに由来する構成単位IIが好ましく、Ｎ−イソプロピルアクリルアミド（ＮＩＰＡＭ）がより好ましい。 The water-soluble polymer compound A may contain a structural unit other than the structural unit I as long as the effects of the present invention are exhibited. When a structural unit other than the structural unit I (also referred to as “structural unit II”) is included, the structural unit other than the structural unit I reduces the surface defects (LPD) and surface roughness (haze) of the silicon wafer. From the viewpoint, at least one monomer selected from the group consisting of N-isopropylacrylamide (NIPAM), acrylic acid (AA), methacrylic acid (MAA), vinylpyrrolidone (VP), dimethylacrylamide (DMAA) and diethylacrylamide (DEAA) Is preferable, and N-isopropylacrylamide (NIPAM) is more preferable.
尚、水溶性高分子化合物Ａが、一般式（１）で表される構成単位Iと構成単位I以外の構成単位IIとを含む共重合体である場合、構成単位Iと構成単位IIの共重合体における構成単位の配列は、ブロックでもランダムでもよい。 In the case where the water-soluble polymer compound A is a copolymer containing the structural unit I represented by the general formula (1) and the structural unit II other than the structural unit I, the structural unit I and the structural unit II The arrangement of the structural units in the polymer may be block or random.
水溶性高分子化合物Ａの具体例としては、ＨＥＡＡ単独重合体、ＨＭＡＡ単独重合体、ＨＥＡＡとＨＭＡＡの共重合体、ＨＥＡＡとＮＩＰＡＭの共重合体、ＨＭＡＡとＮＩＰＡＭの共重合体、ＨＥＡＡとＨＭＡＡとＮＩＰＡＭの共重合体、ＨＥＡＡとＡＡの共重合体、ＨＥＡＡとＭＡＡの共重合体、ＨＥＡＡとＶＰの共重合体、ＨＥＡＡとＤＭＡＡの共重合体、ＨＥＡＡとＤＥＡＡの共重合体、ＨＭＡＡとＡＡの共重合体、ＨＭＡＡとＭＡＡの共重合体、ＨＭＡＡとＶＰの共重合体、ＨＭＡＡとＤＭＡＡの共重合体、ＨＭＡＡとＤＥＡＡの共重合体等のアクリルアミド誘導体に由来の構成単位を含む単独重合体又は共重合体が挙げられ、これらは１種単独又は２種以上用いられてもよいが、シリコンウェーハの表面欠陥の低減の観点から、ＨＥＡＡ単独重合体、ＨＭＡＡ単独重合体、ＨＥＡＡとＨＭＡＡの共重合体、ＨＥＡＡとＮＩＰＡＭの共重合体、ＨＭＡＡとＮＩＰＡＭの共重合体、ＨＥＡＡとＨＭＡＡとＮＩＰＡＭの共重合体が好ましく、ＨＥＡＡ単独重合体、ＨＭＡＡ単独重合体、及びＨＥＡＡとＨＭＡＡの共重合体からなる群から選ばれる少なくとも１種の重合体がより好ましく、ＨＥＡＡ単独重合体が更に好ましい。 Specific examples of the water-soluble polymer compound A include HEAA homopolymer, HMAA homopolymer, HEAA / HMAA copolymer, HEAA / NIPAM copolymer, HMAA / NIPAM copolymer, HEAA / HMAA, NIPAM copolymer, HEAA and AA copolymer, HEAA and MAA copolymer, HEAA and VP copolymer, HEAA and DMAA copolymer, HEAA and DEAA copolymer, HMAA and AA copolymer A homopolymer containing a structural unit derived from an acrylamide derivative such as a copolymer, a copolymer of HMAA and MAA, a copolymer of HMAA and VP, a copolymer of HMAA and DMAA, a copolymer of HMAA and DEAA, or Copolymers may be mentioned, and these may be used alone or in combination of two or more. From the viewpoint of reducing surface defects of the silicon wafer, H AA homopolymer, HMAA homopolymer, HEAA and HMAA copolymer, HEAA and NIPAM copolymer, HMAA and NIPAM copolymer, HEAA, HMAA and NIPAM copolymer are preferred, HEAA homopolymer More preferred is at least one polymer selected from the group consisting of HMAA homopolymers and copolymers of HEAA and HMAA, and more preferred is HEAA homopolymer.
水溶性高分子化合物Ａの重量平均分子量は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、５万以上が好ましく、１０万以上がより好ましく、２０万以上が更に好ましく、３０万以上が更により好ましく、４０万以上が更により好ましく、また、２００万以下が好ましく、１５０万以下がより好ましく、１００万以下が更に好ましく、９０万以下が更により好ましく、８０万以下が更により好ましい。水溶性高分子化合物Ａの重量平均分子量は後の実施例に記載の方法により測定される。 The weight average molecular weight of the water-soluble polymer compound A is preferably 50,000 or more, more preferably 100,000 or more, and more preferably 200,000 or more from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. More preferably, 300,000 or more is even more preferable, 400,000 or more is even more preferable, 2 million or less is preferable, 1.5 million or less is more preferable, 1 million or less is further preferable, 900,000 or less is even more preferable, 80 Even more preferred is 10,000 or less. The weight average molecular weight of the water-soluble polymer compound A is measured by the method described in the examples below.
＜ヒドロキシエチルセルロース（ＨＥＣ）＞
本発明の製造方法及び本発明の研磨方法で使用される研磨液組成物に含まれる水溶性高分子化合物（成分Ｂ）の一例であるヒドロキシエチルセルロース（ＨＥＣ）は、セルロースを構造ユニットとして含有する水溶性高分子化合物（セルロース誘導体）である。
<Hydroxyethyl cellulose (HEC)>
Hydroxyethyl cellulose (HEC), which is an example of the water-soluble polymer compound (component B) contained in the polishing liquid composition used in the production method of the present invention and the polishing method of the present invention, is a water-soluble solution containing cellulose as a structural unit. Functional polymer compound (cellulose derivative).
ＨＥＣの重量平均分子量は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、１０万以上が好ましく、２０万以上がより好ましく、２４万以上が更に好ましい。また、ＨＥＣの重量平均分子量は、シリカ粒子の凝集抑制の観点から、１５０万以下が好ましく、１１０万以下がより好ましく、９０万以下が更に好ましい。ＨＥＣ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により、実施例に記載の測定条件でポリエチレングリコールを標準として求めることができる。 The weight average molecular weight of HEC is preferably 100,000 or more, more preferably 200,000 or more, and further preferably 240,000 or more, from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. In addition, the weight average molecular weight of HEC is preferably 1.5 million or less, more preferably 1.1 million or less, and still more preferably 900,000 or less from the viewpoint of suppressing aggregation of silica particles. The weight average molecular weight of HEC can be obtained by gel permeation chromatography using polyethylene glycol as a standard under the measurement conditions described in the examples.
前記研磨液組成物の濃縮液に含まれる水溶性高分子化合物（成分Ｂ）の含有量は、製造及び輸送コストを低くできる等の経済性の観点から、５００質量ｐｐｍ以上が好ましく、１０００質量ｐｐｍ以上がより好ましく、４０００質量ｐｐｍ以上が更に好ましく、また、保存安定性の向上の観点から、５００００質量ｐｐｍ以下が好ましく、３００００質量ｐｐｍ以下がより好ましく、２００００質量ｐｐｍ以下が更に好ましく、１５０００質量ｐｐｍ以下が更により好ましい。 The content of the water-soluble polymer compound (component B) contained in the concentrated liquid of the polishing composition is preferably 500 ppm by mass or more, and 1000 ppm by mass from the viewpoint of economics such as reduction in production and transportation costs. The above is more preferable, 4000 mass ppm or more is more preferable, and from the viewpoint of improving storage stability, 50000 mass ppm or less is preferable, 30000 mass ppm or less is more preferable, 20000 mass ppm or less is further preferable, and 15000 mass ppm. The following are even more preferred:
前記研磨液組成物の濃縮液に含まれる水溶性高分子化合物（成分Ｂ）とシリカ粒子（成分Ａ）の質量比（水溶性高分子化合物の質量／シリカ粒子の質量）は、シリカ粒子の分散性向上の観点及びシリコンウェーハの表面欠陥の低減の観点から、０．００５以上が好ましく、０．００７５以上がより好ましく、０．００９以上が更に好ましく、０．０１５以上が更により好ましく、また、１．０以下が好ましく、０．８以下がより好ましく、０．６以下が更に好ましく、０．４以下が更により好ましく、０．３以下が更により好ましい。 The mass ratio of the water-soluble polymer compound (component B) and the silica particles (component A) contained in the concentrated liquid of the polishing liquid composition (the mass of the water-soluble polymer compound / the mass of the silica particles) is the dispersion of the silica particles. From the viewpoint of improving the surface property and reducing the surface defects of the silicon wafer, 0.005 or more is preferable, 0.0075 or more is more preferable, 0.009 or more is more preferable, 0.015 or more is even more preferable, 1.0 or less is preferred, 0.8 or less is more preferred, 0.6 or less is more preferred, 0.4 or less is even more preferred, and 0.3 or less is even more preferred.
［塩基性化合物（成分Ｃ）］
本発明の製造方法及び本発明の研磨方法で使用される研磨液組成物の濃縮液には、研磨液組成物の保存安定性の向上、研磨速度の確保、シリコンウェーハの表面欠陥（ＬＰＤ）の低減の観点から、水溶性の塩基性化合物（成分Ｃ）が含まれる。
[Basic compound (component C)]
The concentrated liquid of the polishing liquid composition used in the production method of the present invention and the polishing method of the present invention includes improved storage stability of the polishing liquid composition, ensuring of a polishing rate, and surface defects (LPD) of silicon wafers. From the viewpoint of reduction, a water-soluble basic compound (component C) is included.
水溶性の塩基性化合物（成分Ｃ）としては、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種類以上の含窒素塩基性化合物である。前記研磨液組成物の濃縮液に含まれる含窒素塩基性化合物（成分Ｃ）は、本発明の実施濃度領域において溶解していれば特にその溶解度は限定されないが、ここで、「水溶性」とは、水に対して０．５ｇ／１００ｍｌ以上の溶解度を有することをいい、好ましくは２ｇ／１００ｍｌ以上の溶解度を有することをいい、「水溶性の塩基性化合物」とは、水に溶解したとき、塩基性を示す化合物をいう。 The water-soluble basic compound (component C) is at least one nitrogen-containing basic compound selected from amine compounds and ammonium compounds. The solubility of the nitrogen-containing basic compound (component C) contained in the concentrated liquid of the polishing liquid composition is not particularly limited as long as it is dissolved in the working concentration range of the present invention. Means having a solubility of 0.5 g / 100 ml or more in water, preferably having a solubility of 2 g / 100 ml or more, and “water-soluble basic compound” means when dissolved in water Refers to a compound that exhibits basicity.
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種類以上の含窒素塩基性化合物としては、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、メチルアミン、ジメチルアミン、トリメチルアミン、エチルアミン、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、及び水酸化テトラメチルアンモニウムが挙げられる。これらの含窒素塩基性化合物は２種以上を混合して用いてもよい。前記研磨液組成物の濃縮液に含まれる含窒素塩基性化合物としては、シリコンウェーハの表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）の低減、前記研磨液組成物の濃縮液の保存安定性の向上、及び、研磨速度の確保の観点からアンモニアがより好ましい。 Examples of at least one nitrogen-containing basic compound selected from amine compounds and ammonium compounds include ammonia, ammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, Monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyl-N, N-diethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanol Amine, N- (β-aminoethyl) ethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, ethylenediamine, hexamethylenedia Down, piperazine hexahydrate, anhydrous piperazine, 1- (2-aminoethyl) piperazine, N- methylpiperazine, diethylenetriamine, and tetramethylammonium and the like hydroxide. These nitrogen-containing basic compounds may be used as a mixture of two or more. The nitrogen-containing basic compound contained in the concentrated liquid of the polishing liquid composition includes a reduction in surface roughness (haze) and surface defects (LPD) of the silicon wafer, and storage stability of the concentrated liquid of the polishing liquid composition. Ammonia is more preferable from the viewpoint of improvement and ensuring of the polishing rate.
前記研磨液組成物の濃縮液に含まれる塩基性化合物（成分Ｃ）の含有量は、製造及び輸送コストを低くできる等の経済性の観点から、１０００質量ｐｐｍ以上が好ましく、２０００質量ｐｐｍ以上がより好ましく、３０００質量ｐｐｍ以上が更に好ましい。また、前記濃縮液中における塩基性化合物の含有量は、保存安定性の向上の観点から５００００質量ｐｐｍ以下が好ましく、１００００質量ｐｐｍ以下がより好ましく、６０００質量ｐｐｍ以下が更に好ましい。 The content of the basic compound (component C) contained in the concentrated liquid of the polishing composition is preferably 1000 ppm by mass or more, more preferably 2000 ppm by mass or more, from the viewpoint of economy such that production and transportation costs can be reduced. More preferred is 3000 mass ppm or more. Further, the content of the basic compound in the concentrated liquid is preferably 50000 mass ppm or less, more preferably 10000 mass ppm or less, and still more preferably 6000 mass ppm or less from the viewpoint of improving storage stability.
[水系媒体]
前記研磨液組成物の濃縮液に含まれる水系媒体としては、イオン交換水や超純水等の水、又は水と溶媒との混合媒体等が挙げられ、上記溶媒としては、水と混合可能な溶媒（例えば、エタノール等のアルコール）が好ましい。水系媒体としては、なかでも、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ(ヘイズ)の低減の観点から、イオン交換水又は超純水がより好ましく、超純水が更に好ましい。前記水系媒体が、水と溶媒との混合媒体である場合、混合媒体全体に対する水の割合は、本発明の効果が妨げられなければ、特に限定されるわけではないが、経済性の観点から、９５質量％以上が好ましく、９８質量％以上がより好ましく、実質的に１００質量％が更に好ましく、１００質量％が更により好ましい。
[Aqueous medium]
Examples of the aqueous medium contained in the concentrated liquid of the polishing liquid composition include water such as ion-exchanged water and ultrapure water, or a mixed medium of water and a solvent. The solvent can be mixed with water. Solvents (eg, alcohols such as ethanol) are preferred. Among these, ion-exchanged water or ultrapure water is more preferable, and ultrapure water is more preferable from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. In the case where the aqueous medium is a mixed medium of water and a solvent, the ratio of water to the entire mixed medium is not particularly limited as long as the effect of the present invention is not hindered. 95 mass% or more is preferable, 98 mass% or more is more preferable, 100 mass% is still more preferable substantially, and 100 mass% is still more preferable.
前記研磨液組成物の濃縮液に含まれる水系媒体の含有量は、特に限定されるわけではなく、シリカ粒子、水溶性高分子、塩基性化合物、及び後述する任意成分の残余であってよい。 The content of the aqueous medium contained in the concentrated liquid of the polishing liquid composition is not particularly limited, and may be the remainder of silica particles, water-soluble polymer, basic compound, and optional components described later.
前記研磨液組成物の濃縮液の２５℃におけるｐＨは、表面粗さ(ヘイズ)の低減の観点から、８以上が好ましく、９以上がより好ましく、１０以上が更に好ましく、また、１３以下が好ましく、１２以下がより好ましく、１１以下が更に好ましい。ｐＨの調整は、ｐＨ調整剤（例えば、アンモニア）を適宜添加して行うことができる。ここで、２５℃におけるｐＨは、ｐＨメータ（東亜電波工業株式会社、ＨＭ−３０Ｇ）を用いて測定でき、電極の研磨液組成物への浸漬後１分後の数値である。 The pH of the concentrated liquid of the polishing composition at 25 ° C. is preferably 8 or more, more preferably 9 or more, further preferably 10 or more, and preferably 13 or less from the viewpoint of reducing the surface roughness (haze). , 12 or less is more preferable, and 11 or less is more preferable. The pH can be adjusted by appropriately adding a pH adjusting agent (for example, ammonia). Here, the pH at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is a value one minute after immersion of the electrode in the polishing composition.
［ポリオキシアルキレン化合物（成分Ｄ）］
本発明の研磨液組成物は、更にポリオキシアルキレン化合物を含んでいてもよい。ポリオキシアルキレン化合物は、被研磨シリコンウェーハに吸着する。その為、ポリオキシアルキレン化合物は、塩基性化合物によるウェーハ表面の腐食を抑制しつつ、ウェーハ表面に濡れ性を付与することにより、ウェーハ表面の乾燥により生じると考えられるウェーハ表面へのパーティクルの付着を抑制するよう作用する。また、研磨されたシリコンウェーハの洗浄工程において、ポリオキシアルキレン化合物が、シリカ粒子とシリコンウェーハとの間におこる相互作用を弱める。したがって、ポリオキシアルキレン化合物は、水溶性高分子化合物と相まって、表面粗さ（ヘイズ）と表面欠陥（ＬＰＤ）の低減を増進するものと考えられる。
[Polyoxyalkylene compound (component D)]
The polishing liquid composition of the present invention may further contain a polyoxyalkylene compound. The polyoxyalkylene compound is adsorbed on the silicon wafer to be polished. Therefore, the polyoxyalkylene compound suppresses the corrosion of the wafer surface by the basic compound, and imparts wettability to the wafer surface, thereby preventing the adhesion of particles to the wafer surface, which is considered to be caused by drying of the wafer surface. Acts to suppress. Further, in the cleaning process of the polished silicon wafer, the polyoxyalkylene compound weakens the interaction that occurs between the silica particles and the silicon wafer. Therefore, it is considered that the polyoxyalkylene compound, together with the water-soluble polymer compound, promotes the reduction of surface roughness (haze) and surface defects (LPD).
前記研磨液組成物の濃縮液には、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、助剤としてポリオキシアルキレン化合物（成分Ｄ）が含まれていてもよい。ポリオキシアルキレン化合物（成分Ｄ）は、多価アルコールアルキレンオキシド付加物であり、多価アルコールにエチレンオキシドやプロピレンオキシド等のアルキレンオキシドを付加重合させて得られる多価アルコール誘導体である。ポリオキシアルキレン化合物は、エチレンオキシ基及びプロピレンオキシ基からなる群から選ばれる少なくとも１種のアルキレンオキシド基を含む。 The concentrated liquid of the polishing composition may contain a polyoxyalkylene compound (component D) as an auxiliary agent from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. . The polyoxyalkylene compound (component D) is a polyhydric alcohol alkylene oxide adduct, and is a polyhydric alcohol derivative obtained by addition polymerization of an alkylene oxide such as ethylene oxide or propylene oxide to a polyhydric alcohol. The polyoxyalkylene compound contains at least one alkylene oxide group selected from the group consisting of an ethyleneoxy group and a propyleneoxy group.
ポリオキシアルキレン化合物（成分Ｄ）の元（原料）となる多価アルコールの水酸基数は、シリコンウェーハ表面へのポリオキシアルキレン化合物の吸着強度を高める観点、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、２個以上が好ましく、研磨速度の確保の観点から、１０個以下が好ましく、８個以下がより好ましく、６個以下が更に好ましく、４個以下が更により好ましい。 The number of hydroxyl groups of the polyhydric alcohol that is the source (raw material) of the polyoxyalkylene compound (component D) is determined from the viewpoint of increasing the adsorption strength of the polyoxyalkylene compound to the surface of the silicon wafer, surface defects (LPD) and surface roughness of the silicon wafer From the viewpoint of reducing the haze, 2 or more are preferable, and from the viewpoint of securing the polishing rate, 10 or less are preferable, 8 or less are more preferable, 6 or less are more preferable, and 4 or less are even more preferable.
ポリオキシアルキレン化合物（成分Ｄ）は、具体的には、ポリエチレングリコール（ＰＥＧ）及びポリプロピレングリコール等のエチレングリコールアルキレンオキシド付加物、グリセリンアルキレンオキシド付加物、ペンタエリスリトールアルキレンオキシド付加物等が挙げられるが、これらの中でも、エチレングリコールアルキレンオキシド付加物が好ましい。 Specific examples of the polyoxyalkylene compound (component D) include ethylene glycol alkylene oxide adducts such as polyethylene glycol (PEG) and polypropylene glycol, glycerin alkylene oxide adducts, pentaerythritol alkylene oxide adducts, and the like. Among these, an ethylene glycol alkylene oxide adduct is preferable.
ポリオキシアルキレン化合物（成分Ｄ）は、エチレンオキシ基（ＥＯ）及びプロピレンオキシ基（ＰＯ）からなる群から選ばれる少なくとも１種のアルキレンオキシド基を含むが、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、ポリオキシアルキレン化合物に含まれるアルキレンオキシド基は、ＥＯ及びＰＯからなる群から選ばれる少なくとも１種のアルキレンオキシド基からなると好ましく、ＥＯからなるとより好ましい。ポリオキシアルキレン化合物が、ＥＯとＰＯの両方を含む場合、ＥＯとＰＯの配列はブロックでもランダムでもよい。 The polyoxyalkylene compound (component D) contains at least one alkylene oxide group selected from the group consisting of an ethyleneoxy group (EO) and a propyleneoxy group (PO), but has a surface defect (LPD) and a surface of a silicon wafer. From the viewpoint of reducing roughness (haze), the alkylene oxide group contained in the polyoxyalkylene compound is preferably composed of at least one alkylene oxide group selected from the group consisting of EO and PO, and more preferably composed of EO. When the polyoxyalkylene compound contains both EO and PO, the arrangement of EO and PO may be block or random.
ポリオキシアルキレン化合物（成分Ｄ）の重量平均分子量は、ポリオキシアルキレン化合物の被研磨シリコンウェーハへの吸着量を増大させて、表面粗さ（ヘイズ）を低減する観点から、５００以上が好ましく、７００以上がより好ましく、９００以上が更に好ましく、水溶性高分子のシリカ粒子への吸着量を増大させて、表面粗さ（ヘイズ）を低減する観点から、２５万以下が好ましく、１０万以下がより好ましく、２万以下が更に好ましく、１万以下が更により好ましい。ポリオキシアルキレン化合物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できる。
〈測定条件〉
装置：HLC-8320 GPC(東ソー株式会社、検出器一体型)
カラム：GMPWXL+GMPWXL（アニオン）
溶離液：0.2Mリン酸バッファー／CH3CN＝９／１
流量：0.5ml/min
カラム温度：40℃
検出器：RI 検出器
標準物質：重量平均分子量が既知の単分散ポリエチレングリコール
The weight average molecular weight of the polyoxyalkylene compound (component D) is preferably 500 or more from the viewpoint of increasing the adsorption amount of the polyoxyalkylene compound to the polished silicon wafer and reducing the surface roughness (haze). The above is more preferable, 900 or more is further preferable, and 250,000 or less is preferable and 100,000 or less is more preferable from the viewpoint of increasing the adsorption amount of the water-soluble polymer to the silica particles and reducing the surface roughness (haze). Preferably, 20,000 or less is further preferable, and 10,000 or less is even more preferable. The weight average molecular weight of the polyoxyalkylene compound can be calculated based on a peak in a chromatogram obtained by applying a gel permeation chromatography (GPC) method under the following conditions.
<Measurement condition>
Equipment: HLC-8320 GPC (Tosoh Corporation, detector integrated type)
Column: GMPWXL + GMPWXL (anion)
Eluent: 0.2M phosphate buffer / CH 3 CN = 9/1
Flow rate: 0.5ml / min
Column temperature: 40 ° C
Detector: RI Detector Reference material: Monodispersed polyethylene glycol with known weight average molecular weight
前記研磨液組成物の濃縮液に含まれるポリオキシアルキレン化合物（成分Ｄ）の含有量は、製造及び輸送コストを低くできる等の経済性の観点から、５質量ｐｐｍ以上が好ましく、１０質量ｐｐｍ以上がより好ましく、１５質量ｐｐｍ以上が更に好ましく、また、保存安定性の向上の観点から、５０００質量ｐｐｍ以下が好ましく、３０００質量ｐｐｍ以下がより好ましく、１５００質量ｐｐｍ以下が更に好ましく、１０００質量ｐｐｍ以下が更により好ましく、２５０質量ｐｐｍ以下が更により好ましい。 The content of the polyoxyalkylene compound (component D) contained in the concentrated liquid of the polishing composition is preferably 5 ppm by mass or more, and preferably 10 ppm by mass or more from the viewpoint of economy such that production and transportation costs can be reduced. More preferably, 15 mass ppm or more is more preferable, and from the viewpoint of improving storage stability, 5000 mass ppm or less is preferable, 3000 mass ppm or less is more preferable, 1500 mass ppm or less is further preferable, and 1000 mass ppm or less. Is more preferable, and 250 mass ppm or less is even more preferable.
前記研磨液組成物の濃縮液に含まれるポリオキシアルキレン化合物（成分Ｄ）とシリカ粒子（成分Ａ）の質量比（ポリオキシアルキレン化合物の質量／シリカ粒子の質量）は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、０．００００４以上が好ましく、０．００１２以上がより好ましく、０．００２以上が更に好ましく、また、０．０２以下が好ましく、０．００８０以下がより好ましく、０．００７２以下が更に好ましい。 The mass ratio of the polyoxyalkylene compound (component D) and the silica particles (component A) contained in the concentrated liquid of the polishing composition (the mass of the polyoxyalkylene compound / the mass of the silica particles) is the surface defect of the silicon wafer ( From the viewpoint of reduction of (LPD) and surface roughness (haze), 0.00004 or more is preferable, 0.0012 or more is more preferable, 0.002 or more is further preferable, 0.02 or less is preferable, and 0.0080 is preferable. The following is more preferable, and 0.0072 or less is still more preferable.
前記研磨液組成物の濃縮液に含まれる水溶性高分子化合物（成分Ｂ）とポリオキシアルキレン化合物（成分Ｄ）の質量比（水溶性高分子化合物の質量／ポリオキシアルキレン化合物の質量）は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、１以上が好ましく、３以上がより好ましく、５以上が更に好ましく、また、５００以下が好ましく、２００以下がより好ましく、１００以下が更に好ましく、６０以下が更により好ましく、４０以下が更により好ましい。 The mass ratio of the water-soluble polymer compound (component B) and the polyoxyalkylene compound (component D) contained in the concentrated liquid of the polishing liquid composition (mass of water-soluble polymer compound / mass of polyoxyalkylene compound) is: From the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer, 1 or more is preferable, 3 or more is more preferable, 5 or more is more preferable, 500 or less is preferable, and 200 or less is more preferable. 100 or less is more preferable, 60 or less is still more preferable, and 40 or less is still more preferable.
［その他の任意成分］
前記研磨液組成物の濃縮液には、本発明の効果が妨げられない範囲で、ポリオキシアルキレン化合物（成分Ｄ）以外の任意成分として、更に前記水溶性高分子以外の水溶性高分子化合物、ｐＨ調整剤、防腐剤、アルコール類、キレート剤及びノニオン性界面活性剤から選ばれる少なくとも１種の任意成分が含まれてもよい。
[Other optional ingredients]
In the concentrated liquid of the polishing liquid composition, as an optional component other than the polyoxyalkylene compound (component D), a water-soluble polymer compound other than the water-soluble polymer, as long as the effect of the present invention is not hindered, At least one optional component selected from pH adjusters, preservatives, alcohols, chelating agents and nonionic surfactants may be included.
〈防腐剤〉
防腐剤としては、ベンザルコニウムクロライド、ベンゼトニウムクロライド、１，２−ベンズイソチアゾリン−３−オン、（５−クロロ−）２−メチル−４−イソチアゾリン−３−オン、過酸化水素、又は次亜塩素酸塩等が挙げられる。
<Preservative>
Preservatives include benzalkonium chloride, benzethonium chloride, 1,2-benzisothiazolin-3-one, (5-chloro-) 2-methyl-4-isothiazolin-3-one, hydrogen peroxide, or hypochlorite Examples include acid salts.
〈アルコール類〉
アルコール類としては、メタノール、エタノール、プロパノール、ブタノール、イソプロピルアルコール、２−メチル−２−プロパノオール、エチレングリコール、プロピレングリコール、ポリエチレングリコール、グリセリン等が挙げられる。アルコール類の含有量は、前記研磨液組成物の濃縮液を希釈して得られる希釈液において、０．１〜５質量％であると好ましい。
<Alcohols>
Examples of alcohols include methanol, ethanol, propanol, butanol, isopropyl alcohol, 2-methyl-2-propanool, ethylene glycol, propylene glycol, polyethylene glycol, and glycerin. The content of alcohol is preferably 0.1 to 5% by mass in a diluted solution obtained by diluting the concentrated liquid of the polishing composition.
〈キレート剤〉
キレート剤としては、エチレンジアミン四酢酸、エチレンジアミン四酢酸ナトリウム、ニトリロ三酢酸、ニトリロ三酢酸ナトリウム、ニトリロ三酢酸アンモニウム、ヒドロキシエチルエチレンジアミン三酢酸、ヒドロキシエチルエチレンジアミン三酢酸ナトリウム、トリエチレンテトラミン六酢酸、トリエチレンテトラミン六酢酸ナトリウム等が挙げられる。キレート剤の含有量は、前記研磨液組成物の濃縮液を希釈して得られる希釈液において、０．０１〜１質量％であると好ましい。
<Chelating agent>
Chelating agents include: ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetate, hydroxyethylethylenediaminetriacetic acid, sodium hydroxyethylethylenediaminetriacetate, triethylenetetraminehexaacetic acid, triethylenetetramine Examples include sodium hexaacetate. The content of the chelating agent is preferably 0.01 to 1% by mass in a diluted liquid obtained by diluting the concentrated liquid of the polishing liquid composition.
〈非イオン性界面活性剤〉
非イオン性界面活性剤としては、ポリオキシエチレンソルビタン脂肪酸エステル、ポリオキシエチレンソルビット脂肪酸エステル、ポリオキシエチレングリセリン脂肪酸エステル、ポリオキシエチレン脂肪酸エステル、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシアルキレン（硬化）ヒマシ油等のポリエチレングリコール型と、ショ糖脂肪酸エステル、ポリグリセリンアルキルエーテル、ポリグリセリン脂肪酸エステル、アルキルグリコシド等の多価アルコール型及び脂肪酸アルカノールアミド等が挙げられる。
<Nonionic surfactant>
Nonionic surfactants include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, Examples include polyethylene glycol types such as oxyalkylene (cured) castor oil, polyhydric alcohol types such as sucrose fatty acid ester, polyglycerin alkyl ether, polyglycerin fatty acid ester, alkylglycoside, and fatty acid alkanolamide.
次に、前記研磨液組成物の濃縮液の調製方法の一例について説明する。 Next, an example of a method for preparing a concentrated liquid of the polishing liquid composition will be described.
前記研磨液組成物の濃縮液の調製方法は、何ら制限されず、前記研磨液組成物の濃縮液は、例えば、水溶性高分子化合物（成分Ｂ）と塩基性化合物（成分Ｃ）とシリカ粒子（成分Ａ）と水系媒体と、必要に応じて任意成分とを混合することによって調製できる。 The method of preparing the concentrated liquid of the polishing liquid composition is not limited, and the concentrated liquid of the polishing liquid composition may be, for example, a water-soluble polymer compound (component B), a basic compound (component C), and silica particles. It can be prepared by mixing (Component A), an aqueous medium, and optional components as necessary.
シリカ粒子（成分Ａ）の水系媒体への分散は、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。シリカ粒子の凝集等により生じた粗大粒子が水系媒体中に含まれる場合、遠心分離やフィルターを用いたろ過等により、当該粗大粒子を除去すると好ましい。シリカ粒子（成分Ａ）の水系媒体への分散は、水溶性高分子化合物（成分Ｂ）の存在下で行うと好ましい。 The silica particles (component A) can be dispersed in an aqueous medium using, for example, a homomixer, a homogenizer, an ultrasonic disperser, a wet ball mill, a stirrer such as a bead mill, or the like. When coarse particles generated by aggregation of silica particles or the like are contained in an aqueous medium, it is preferable to remove the coarse particles by centrifugation or filtration using a filter. The dispersion of the silica particles (component A) in the aqueous medium is preferably performed in the presence of the water-soluble polymer compound (component B).
本発明の製造方法及び本発明の研磨方法では、研磨液組成物の濃縮液を調製した後、当該濃縮液を、所定の保存時間、保存してから、前記濃縮液を、水系媒体で所定の希釈倍率で希釈し、得られた希釈液（研磨液組成物）を所定の時間以内に被研磨シリコンウェーハの研磨に使用する。 In the production method of the present invention and the polishing method of the present invention, after preparing a concentrated liquid of the polishing liquid composition, the concentrated liquid is stored for a predetermined storage time, and then the concentrated liquid is stored in a predetermined amount with an aqueous medium. The diluted liquid (polishing liquid composition) obtained by diluting at a dilution rate is used for polishing the silicon wafer to be polished within a predetermined time.
前記研磨液組成物の濃縮液は、表面粗さ(ヘイズ)の低減の観点から、可能なかぎり空気及び光が入らないように容器に充填された状態で保存されると好ましい。また、研磨液組成物の濃縮液を保存する雰囲気の温度は、１℃〜４５℃であると好ましい。 From the viewpoint of reducing the surface roughness (haze), the concentrated liquid of the polishing composition is preferably stored in a state in which the container is filled so that air and light do not enter as much as possible. Moreover, it is preferable that the temperature of the atmosphere which preserve | saves the concentrate of polishing liquid composition is 1 degreeC-45 degreeC.
研磨液組成物の濃縮液の前記保存時間は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ(ヘイズ)の安定した低減を可能とする観点から、１４日（１４日±６時間）以上、好ましくは２１日（２１日±６時間）以上、より好ましくは３０日（３０日±６時間）以上であり、７２０日（７２０日±６時間）以下、好ましくは３６０日（３６０±６時間）以下、より好ましくは１８０日（１８０日±６時間）以下である。尚、前記「保存時間」は、前記濃縮液の構成成分を混合し終わった時点からカウントされ、当該時点から、希釈が開始される前までに経過した時間である。従って、前記「保存時間」は、倉庫等で保存されている時間のみならず、輸送等が行われている場合は当該輸送時間も含む。 From the viewpoint of enabling stable reduction of surface defects (LPD) and surface roughness (haze) of the silicon wafer, the storage time of the concentrated liquid of the polishing liquid composition is 14 days (14 days ± 6 hours) or more, Preferably it is 21 days (21 days ± 6 hours) or more, more preferably 30 days (30 days ± 6 hours) or more, 720 days (720 days ± 6 hours) or less, preferably 360 days (360 ± 6 hours) In the following, it is more preferably 180 days (180 days ± 6 hours) or less. The “storage time” is counted from the time when the components of the concentrate are mixed, and is the time elapsed from the time until the dilution is started. Therefore, the “storage time” includes not only the time stored in a warehouse or the like, but also the transportation time when transportation or the like is performed.
希釈液（研磨液組成物）が被研磨シリコンウェーハの研磨に使用されるまでの前記所定の時間は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ(ヘイズ)の安定した低減を可能とする観点から、２日（２日±６時間）以下、好ましくは１日（１日±６時間）以下であるが、希釈液は、調製直後、即ち、水系媒体に濃縮液を添加し、濃度が均一になるまでこれらを十分に撹拌することにより希釈液を得た直後に使用されるのがより好ましい。尚、希釈液（研磨液組成物）が被研磨シリコンウェーハの研磨に使用されるまでの前記「所定の時間」は、希釈液の調製直後からカウントされ、当該時点から研磨機に供給されるまでに経過した時間である。 The predetermined time until the diluted solution (polishing solution composition) is used for polishing the silicon wafer to be polished enables stable reduction of surface defects (LPD) and surface roughness (haze) of the silicon wafer. From the viewpoint, it is 2 days (2 days ± 6 hours) or less, preferably 1 day (1 day ± 6 hours) or less, but the diluted solution is immediately after preparation, that is, a concentrated solution is added to an aqueous medium, and the concentration is More preferably, they are used immediately after obtaining a diluted solution by sufficiently stirring them until uniform. The “predetermined time” until the diluting liquid (polishing liquid composition) is used for polishing the silicon wafer to be polished is counted immediately after the diluting liquid is prepared and is supplied to the polishing machine from that time. Is the time that has passed.
前記希釈倍率は、濃縮液の製造及び輸送コストを低くできる等の経済性の観点から、２倍以上が好ましく、１０倍以上がより好ましく、２０倍以上が更に好ましく、３０倍以上が更により好ましく、また、１００倍以下が好ましく、８０倍以下がより好ましく、７０倍以下が更に好ましく、５０倍以下が更により好ましい。 The dilution ratio is preferably 2 times or more, more preferably 10 times or more, still more preferably 20 times or more, and even more preferably 30 times or more, from the viewpoint of economy such that the production and transportation cost of the concentrate can be reduced. Moreover, 100 times or less is preferable, 80 times or less is more preferable, 70 times or less is still more preferable, and 50 times or less is still more preferable.
前記希釈液に含まれるシリカ粒子（成分Ａ）の含有量は、研磨速度の確保の観点から、５００質量ｐｐｍ以上が好ましく、７００質量ｐｐｍ以上がより好ましく、９００質量ｐｐｍ以上が更に好ましい。また、経済性及び研磨液組成物の保存安定性の向上の観点から１０００００質量ｐｐｍ以下が好ましく、７５０００質量ｐｐｍ％以下がより好ましく、５００００質量ｐｐｍ以下が更に好ましく、１００００質量ｐｐｍ以下が更により好ましく、５０００質量ｐｐｍ以下が更により好ましい。 The content of the silica particles (component A) contained in the diluent is preferably 500 mass ppm or more, more preferably 700 mass ppm or more, and still more preferably 900 mass ppm or more, from the viewpoint of ensuring the polishing rate. Further, from the viewpoint of economy and improvement in storage stability of the polishing composition, it is preferably 100,000 ppm by weight or less, more preferably 75,000 ppm by weight or less, further preferably 50,000 ppm by weight or less, and even more preferably 10,000 ppm by weight or less. Even more preferred is 5000 ppm by mass or less.
前記希釈液に水溶性高分子化合物（成分Ｂ）の含有量は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、６０質量ｐｐｍ以上であり、７０質量ｐｐｍ以上が好ましく、８０質量ｐｐｍ以上がより好ましく、５２０質量ｐｐｍ以下であり、３００質量ｐｐｍ以下が好ましく、２５０質量ｐｐｍ以下がより好ましく、２００質量ｐｐｍ以下が更に好ましい。 The content of the water-soluble polymer compound (component B) in the diluent is 60 mass ppm or more and 70 mass ppm or more from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. 80 mass ppm or more is more preferable, 520 mass ppm or less is preferable, 300 mass ppm or less is preferable, 250 mass ppm or less is more preferable, and 200 mass ppm or less is still more preferable.
前記希釈液に含まれる塩基性化合物（成分Ｃ）の含有量は、シリコンウェーハの表面欠陥の低減、研磨液組成物の保存安定性の向上、及び研磨速度の確保の観点から、６０質量ｐｐｍ以上であり、７０質量ｐｐｍ以上が好ましく、８０質量ｐｐｍ以上がより好ましく、１００質量ｐｐｍ以上が更に好ましい。また、３００質量ｐｐｍ以下であり、２５０質量ｐｐｍ以下が好ましく、２００量ｐｐｍ以下がより好ましく、１７５質量ｐｐｍ以下が更に好ましく、１５０質量ｐｐｍ以下が更により好ましい。 The content of the basic compound (component C) contained in the diluent is 60 ppm by mass or more from the viewpoint of reducing surface defects of the silicon wafer, improving the storage stability of the polishing composition, and ensuring the polishing rate. 70 mass ppm or more is preferable, 80 mass ppm or more is more preferable, and 100 mass ppm or more is still more preferable. Moreover, it is 300 mass ppm or less, 250 mass ppm or less is preferable, 200 mass ppm or less is more preferable, 175 mass ppm or less is further more preferable, 150 mass ppm or less is still more preferable.
前記希釈液にポリオキシアルキレン化合物（成分Ｄ）が含まれる場合、ポリオキシアルキレン化合物（成分Ｄ）の含有量は、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減の観点から、０．４質量ｐｐｍ以上が好ましく、０．５質量ｐｐｍ以上がより好ましく、０．８質量ｐｐｍ以上が更に好ましく、また、保存安定性の向上の観点から、１００質量ｐｐｍ以下が好ましく、５０質量ｐｐｍ以下がより好ましく、２５質量ｐｐｍ以下が更に好ましく、１０質量ｐｐｍ以下が更により好ましい。 When the dilute solution contains a polyoxyalkylene compound (component D), the content of the polyoxyalkylene compound (component D) is from the viewpoint of reducing surface defects (LPD) and surface roughness (haze) of the silicon wafer. 0.4 mass ppm or more is preferable, 0.5 mass ppm or more is more preferable, 0.8 mass ppm or more is more preferable, and from the viewpoint of improving storage stability, 100 mass ppm or less is preferable, and 50 mass ppm. More preferably, ppm or less is more preferable, 25 mass ppm or less is still more preferable, and 10 mass ppm or less is still more preferable.
前記希釈液は、研磨速度の確保、シリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の低減、及び研磨液組成物の保存安定性の向上の観点から、成分Ａを９００質量ｐｐｍ以上５０００質量ｐｐｍ以下の濃度で含み、成分Ｂを６０質量ｐｐｍ以上５２０質量ｐｐｍ以下の濃度で含み、成分Ｃを６０質量ｐｐｍ以上３００質量ｐｐｍ以下の濃度で含むと好ましい。前記希釈液に成分Ｄが含まれる場合、前記希釈液は、成分Ａを９００質量ｐｐｍ以上５０００質量ｐｐｍ以下の濃度で含み、成分Ｂを６０質量ｐｐｍ以上５２０質量ｐｐｍ以下の濃度で含み、成分Ｃを６０質量ｐｐｍ以上３００質量ｐｐｍ以下の濃度で含み、成分Ｄを０．８質量ｐｐｍ以上１０質量ｐｐｍ以下の濃度で含むと好ましい。 The dilution liquid contains component A in an amount of 900 ppm by mass or more from the viewpoint of securing the polishing rate, reducing the surface defects (LPD) and surface roughness (haze) of the silicon wafer, and improving the storage stability of the polishing composition. It is preferable that it is contained at a concentration of 5000 ppm by mass or less, Component B is contained at a concentration of 60 ppm to 520 ppm by mass, and Component C is contained at a concentration of 60 ppm to 300 ppm by mass. When component D is contained in the diluent, the diluent includes component A at a concentration of 900 ppm to 5000 ppm, component B at a concentration of 60 ppm to 520 ppm, and component C. Is contained at a concentration of 60 mass ppm to 300 mass ppm, and component D is preferably contained at a concentration of 0.8 mass ppm to 10 mass ppm.
前記希釈液の２５℃におけるｐＨは、研磨速度の確保の観点から、８．０以上が好ましく、９．０以上がより好ましく、１０以上が更に好ましく、また、１２．０以下が好ましく、１１．５以下がより好ましく、１１．０以下が更に好ましい。２５℃における前記希釈液のｐＨは、ｐＨメータ（東亜電波工業株式会社、ＨＭ−３０Ｇ）を用いて測定でき、電極の研磨液組成物への浸漬後１分後の数値である。 The pH of the diluted solution at 25 ° C. is preferably 8.0 or more, more preferably 9.0 or more, further preferably 10 or more, and preferably 12.0 or less, from the viewpoint of ensuring the polishing rate. 5 or less is more preferable, and 11.0 or less is still more preferable. The pH of the diluent at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is a value one minute after the electrode is immersed in the polishing composition.
前記被研磨シリコンウェーハを研磨する工程には、シリコン単結晶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シリコンウェーハを平坦化するラッピング（粗研磨）工程と、ラッピングされたシリコンウェーハをエッチングした後、シリコンウェーハ表面を鏡面化する仕上げ研磨工程とがある。本発明の研磨液組成物は、上記仕上げ研磨工程で用いられるとより好ましい。 In the process of polishing the silicon wafer to be polished, a lapping process (rough polishing) for flattening the silicon wafer obtained by slicing a silicon single crystal ingot into a thin disk shape, and etching the lapped silicon wafer After that, there is a final polishing process for mirror-finishing the silicon wafer surface. The polishing composition of the present invention is more preferably used in the above-described finish polishing step.
前記被研磨シリコンウェーハを研磨する工程では、例えば、研磨パッドを貼り付けた定盤で被研磨シリコンウェーハを挟み込み、３〜２０ｋＰａの研磨圧力で被研磨シリコンウェーハを研磨する。 In the step of polishing the silicon wafer to be polished, for example, the silicon wafer to be polished is sandwiched between a surface plate to which a polishing pad is attached and the silicon wafer to be polished is polished at a polishing pressure of 3 to 20 kPa.
上記研磨圧力とは、研磨時に被研磨シリコンウェーハの被研磨面に加えられる定盤の圧力をいう。研磨圧力は、研磨速度を向上させ経済的に研磨を行う観点から、３ｋＰａ以上が好ましく、４ｋＰａ以上がより好ましく、５ｋＰａ以上が更に好ましく、５．５ｋＰａ以上が更により好ましい。また、表面品質を向上させ、且つ研磨物の残留応力を緩和する観点から、研磨圧力は、２０ｋＰａ以下が好ましく、より好ましくは１８ｋＰａ以下、更に好ましくは１６ｋＰａ以下である。 The polishing pressure refers to the pressure of the surface plate applied to the surface to be polished of the silicon wafer to be polished at the time of polishing. The polishing pressure is preferably 3 kPa or more, more preferably 4 kPa or more, further preferably 5 kPa or more, and even more preferably 5.5 kPa or more from the viewpoint of improving the polishing rate and economically polishing. Further, from the viewpoint of improving the surface quality and relaxing the residual stress of the polished product, the polishing pressure is preferably 20 kPa or less, more preferably 18 kPa or less, and still more preferably 16 kPa or less.
本発明の製造方法及び本発明の研磨方法では、前記被研磨シリコンウェーハを研磨する工程の前に、前記研磨液組成物の濃縮液を希釈する希釈工程を含む。希釈媒体には、前記水系媒体を用いればよい。 The production method of the present invention and the polishing method of the present invention include a dilution step of diluting the concentrated liquid of the polishing liquid composition before the step of polishing the silicon wafer to be polished. The aqueous medium may be used as the dilution medium.
本発明の製造方法及び本発明の研磨方法は、前記研磨液組成物（希釈液）を用いて被研磨シリコンウェーハを研磨する工程の後に、研磨された被研磨シリコンウェーハを洗浄する工程を更に含む。 The production method of the present invention and the polishing method of the present invention further include a step of cleaning the polished silicon wafer after the step of polishing the silicon wafer to be polished using the polishing composition (diluent). .
（水溶性高分子化合物）
［ＨＥＡＡ単独重合体］
下記の実施例２〜６、８、比較例１及び３で用いた水溶性高分子化合物は下記のようにして合成した。
(Water-soluble polymer compound)
[HEAA homopolymer]
The water-soluble polymer compounds used in the following Examples 2 to 6, 8 and Comparative Examples 1 and 3 were synthesized as follows.
ヒドロキシエチルアクリルアミド150 g(1.30 mol 興人製)を100 gのイオン交換水に溶解し、モノマー水溶液を調製した。また、別に、2,2’-アゾビス（2‐メチルプロピオンアミジン）ジヒドロクロリド 0.035g（重合開始剤、V-50 1.30 mmol 和光純薬製）を70 gのイオン交換水に溶解し、重合開始剤水溶液を調製した。ジムロート冷却管、温度計及び三日月形テフロン製撹拌翼を備えた2Lセパラブルフラスコに、イオン交換水1180 gを投入した後、セパラブルフラスコ内を窒素置換した。次いで、オイルバスを用いてセパラブルフラスコ内の温度を68℃に昇温した後、予め調製した上記モノマー水溶液と上記重合開始剤水溶液を各々3.5時間かけて撹拌を行っているセパラブルフラスコ内に滴下した。滴下終了後、反応溶液の温度及び撹拌を４時間保持し、無色透明の10質量％ポリヒドロキシエチルアクリルアミド（ＨＥＡＡの単独重合体（重量平均分子量：720000）水溶液1500 gを得た。 Hydroxyethyl acrylamide 150 g (1.30 mol manufactured by Kojin Co., Ltd.) was dissolved in 100 g of ion exchange water to prepare an aqueous monomer solution. Separately, 0.035 g of 2,2'-azobis (2-methylpropionamidine) dihydrochloride (polymerization initiator, V-50 1.30 mmol, manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 70 g of ion-exchanged water, and the polymerization initiator was dissolved. An aqueous solution was prepared. After putting 1180 g of ion-exchange water into a 2 L separable flask equipped with a Dimroth condenser, thermometer, and crescent Teflon stirring blade, the inside of the separable flask was purged with nitrogen. Next, after raising the temperature in the separable flask to 68 ° C. using an oil bath, the above-prepared monomer aqueous solution and the above polymerization initiator aqueous solution were each stirred for 3.5 hours in the separable flask. It was dripped. After completion of the dropwise addition, the temperature and stirring of the reaction solution were maintained for 4 hours to obtain 1500 g of a colorless and transparent 10% by mass polyhydroxyethylacrylamide (HEAA homopolymer (weight average molecular weight: 720000) aqueous solution.
下記の実施例１、比較例２では、水溶性高分子化合物として、ヒドロキシエチルセルロース（ＨＥＣ、重量平均分子量２５万）を、実施例７では、水溶性高分子化合物として、ヒドロキシエチルセルロース（ＨＥＣ、重量平均分子量８０万）を用いた。 In Example 1 and Comparative Example 2 below, hydroxyethyl cellulose (HEC, weight average molecular weight 250,000) is used as the water-soluble polymer compound, and in Example 7, hydroxyethyl cellulose (HEC, weight average) is used as the water-soluble polymer compound. Molecular weight 800,000) was used.
〈水溶性高分子化合物の重合平均分子量の測定〉
水溶性高分子化合物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。尚、ＨＥＣの重量平均分子量はカタログ値である。
〈測定条件〉
装置：HLC-8320 GPC(東ソー株式会社、検出器一体型)
カラム：GMPWXL+GMPWXL（アニオン）
溶離液：0.2Mリン酸バッファー／CH3CN＝９／１
流量：0.5ml/min
カラム温度：40℃
検出器：RI 検出器
標準物質：重量平均分子量が既知の単分散ポリエチレングリコール
<Measurement of polymerization average molecular weight of water-soluble polymer compound>
The weight average molecular weight of the water-soluble polymer compound was calculated based on the peak in the chromatogram obtained by applying the gel permeation chromatography (GPC) method under the following conditions. The weight average molecular weight of HEC is a catalog value.
<Measurement condition>
Equipment: HLC-8320 GPC (Tosoh Corporation, detector integrated type)
Column: GMPWXL + GMPWXL (anion)
Eluent: 0.2M phosphate buffer / CH 3 CN = 9/1
Flow rate: 0.5ml / min
Column temperature: 40 ° C
Detector: RI Detector Reference material: Monodispersed polyethylene glycol with known weight average molecular weight
〈水溶性の測定〉
各水溶性高分子化合物の水溶性は、０．５ｇ／１００ｍｌの水溶性高分子化合物水溶液を調整し、下記の評価方法に従って目視で状態を確認した。
（評価方法）
(1)スクリュー管に約９０ｍｌの水を注ぎ、室温で攪拌を開始する。
(2)０．５ｇの水溶性高分子化合物をスクリュー管に計量し投入する。
(3)室温で３時間攪拌した後に、７０度まで昇度し更に３時間攪拌する。
(4)室温まで冷却した後に、水を添加し１００ｍｌとする。
(5)目視で水溶液の状態を確認する。透明であれば、水溶性化合物である。
今回用いた水溶性高分子化合物は全て０．５重量％で透明であり、本発明において水溶性であると判断した。
<Measurement of water solubility>
The water-solubility of each water-soluble polymer compound was prepared by adjusting a 0.5 g / 100 ml water-soluble polymer compound aqueous solution and visually checking the state according to the following evaluation method.
(Evaluation method)
(1) Pour about 90 ml of water into the screw tube and start stirring at room temperature.
(2) Weigh 0.5 g of the water-soluble polymer compound into the screw tube.
(3) After stirring at room temperature for 3 hours, the temperature is raised to 70 degrees and stirring is continued for 3 hours.
(4) After cooling to room temperature, water is added to make 100 ml.
(5) Visually check the state of the aqueous solution. If it is transparent, it is a water-soluble compound.
All the water-soluble polymer compounds used this time were transparent at 0.5% by weight, and were judged to be water-soluble in the present invention.
＜研磨材（シリカ粒子）の平均一次粒子径の測定＞
研磨材の平均一次粒子径（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
<Measurement of average primary particle diameter of abrasive (silica particles)>
The average primary particle diameter (nm) of the abrasive was calculated by the following formula using the specific surface area S (m 2 / g) calculated by the BET (nitrogen adsorption) method.
Average primary particle diameter (nm) = 2727 / S
研磨材の比表面積は、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。
The specific surface area of the abrasive is subjected to the following [pretreatment], and then approximately 0.1 g of a measurement sample is accurately weighed to 4 digits after the decimal point in a measurement cell, and immediately under the measurement at a specific temperature of 110 ° C. for 30 minutes. After drying, the surface area was measured 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).
［前処理］
（ａ）スラリー状の研磨材を硝酸水溶液で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研磨材をシャーレにとり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ーで濾過する。
（ｅ）フィルター上の濾過物を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ーをシャーレにとり、１１０℃の雰囲気下で４時間乾燥させる。
（ｇ）乾燥した濾過物（砥粒）をフィルター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。
[Preprocessing]
(A) The slurry-like abrasive is adjusted to pH 2.5 ± 0.1 with an aqueous nitric acid solution.
(B) A slurry-like abrasive 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 exchange water at 40 ° C. and filtered through a membrane filter having a pore size of 1 μm.
(E) The filtrate on the filter is washed 5 times with 20 g of ion exchange water (40 ° C.).
(F) The filter with the filtrate attached is taken in a petri dish and dried in an atmosphere of 110 ° C. for 4 hours.
(G) The dried filtrate (abrasive grains) was taken so as not to be mixed with filter waste, and finely pulverized with a mortar to obtain a measurement sample.
＜研磨材（シリカ粒子）の平均二次粒子径＞
研磨材の平均二次粒子径（ｎｍ）は、研磨材の濃度が０．２５質量％となるように研磨材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（株）製）を用いて測定した。
<Average secondary particle diameter of abrasive (silica particles)>
The average secondary particle diameter (nm) of the abrasive is such that the abrasive dispersion is added to ion-exchanged water so that the concentration of the abrasive is 0.25% by mass, and the resulting aqueous dispersion is then disposable sizing cuvette (polystyrene). (10 mm cell manufactured) up to a height of 10 mm from the bottom, and measured using a dynamic light scattering method (device name: Zetasizer Nano ZS, manufactured by Sysmex Corporation).
（１）濃縮研磨液組成物の調製方法
イオン交換水に対し、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６７ｎｍ、会合度１．９）、28質量％アンモニア水（キシダ化学（株）試薬特級）、水溶性高分子化合物としてＨＥＡＡ単独重合体又はＨＥＣ、及び必要に応じてポリオキシアルキレン化合物としてＰＥＧ（重量平均分子量6000又は1000、和光純薬工業）を添加し、これらを３０分間攪拌混合して、実施例１〜８、比較例１〜３の濃縮研磨液組成物（pH10.6±0.1（25℃））を得た。表１には、各濃縮研磨液組成物をイオン交換水で４０倍に記載した時の各成分の含有量を記載している。研磨液組成物における、シリカ粒子、水溶性高分子化合物、ポリオキシアルキレン化合物、アンモニアを除いた残余の成分はイオン交換水である。
(1) Preparation method of concentrated polishing liquid composition With respect to ion-exchanged water, silica particles (colloidal silica, average primary particle diameter 35 nm, average secondary particle diameter 67 nm, association degree 1.9), 28% by mass ammonia water (Kishida Chemical Co., Ltd. reagent grade), HEAA homopolymer or HEC as water-soluble polymer compound, and PEG (weight average molecular weight 6000 or 1000, Wako Pure Chemical Industries) as polyoxyalkylene compound as necessary, Were mixed by stirring for 30 minutes to obtain concentrated polishing liquid compositions (pH 10.6 ± 0.1 (25 ° C.)) of Examples 1 to 8 and Comparative Examples 1 to 3. Table 1 shows the content of each component when each concentrated polishing composition is described 40 times with ion-exchanged water. In the polishing composition, the remaining components excluding silica particles, water-soluble polymer compound, polyoxyalkylene compound and ammonia are ion-exchanged water.
（２）研磨方法
（２−１）濃縮研磨液組成物の保存時間が及ぼすシリコンウェーハ表面への影響
濃縮研磨液組成物の調製後、直ちに、濃縮研磨液組成物を、５Ｌ成型液体容器フジテーナー（登録商標）（藤森工業社製）に空気が入らいないように充填し、室温下（２０〜２５度）で所定時間保存した後、濃縮研磨液組成物を４０倍に希釈して希釈研磨液組成物を得た。具体的には、濃縮研磨液組成物とイオン交換水との体積比が１：３９（イオン交換水：濃縮研磨液組成物）となるように、濃縮研磨液組成物をイオン交換水に添加し、これらの濃度が均一になるまでこれらを十分に撹拌（例えば５分間撹拌）することにより希釈研磨液組成物を得た。尚、表１中の記載「濃縮研磨液組成物の調製直後からの日数（時間）」は、前記「保存時間」であり、濃縮研磨液組成物の構成成分の濃度が均一になるまで十分に攪拌（例えば３０分間撹拌）し終わった時点からカウントした。
(2) Polishing method (2-1) Effect of the storage time of the concentrated polishing composition on the silicon wafer surface Immediately after the preparation of the concentrated polishing composition, the concentrated polishing composition is immediately converted into a 5 L molded liquid container Fujitainer ( (Registered Trademark) (made by Fujimori Kogyo Co., Ltd.) so that air does not enter, and after storing at room temperature (20-25 degrees) for a predetermined time, the concentrated polishing composition is diluted 40 times to obtain a diluted polishing composition. I got a thing. Specifically, the concentrated polishing liquid composition is added to the ion exchange water so that the volume ratio of the concentrated polishing liquid composition to the ion exchange water is 1:39 (ion exchange water: concentrated polishing liquid composition). The diluted polishing liquid composition was obtained by sufficiently stirring them (for example, stirring for 5 minutes) until these concentrations became uniform. In addition, the description “days (hours) immediately after preparation of the concentrated polishing composition” in Table 1 is the “preservation time”, which is sufficient until the concentration of the constituent components of the concentrated polishing composition becomes uniform. Counting was started from the end of stirring (for example, stirring for 30 minutes).
濃縮研磨液組成物の希釈後すぐに、得られた希釈研磨液組成物を用いて下記の研磨条件（（２−３）仕上げ研磨条件）で、シリコンウェーハ（直径２００ｍｍのシリコン片面鏡面ウェーハ、伝導型：Ｐ、結晶方位：１００、抵抗率０．１Ω・ｃｍ以上１００Ω・ｃｍ未満）に対して仕上げ研磨を行った。当該仕上げ研磨に先立ってシリコンウェーハに対して市販の研磨剤組成物を用いてあらかじめ粗研磨を実施した。粗研磨を終了したシリコンウェーハの表面粗さ（ヘイズ）は、2.680ppbであった。 Immediately after the dilution of the concentrated polishing composition, a silicon wafer (a silicon single-sided mirror wafer having a diameter of 200 mm, conductive film) using the obtained diluted polishing composition under the following polishing conditions ((2-3) final polishing conditions) (Type: P, crystal orientation: 100, resistivity 0.1 Ω · cm or more and less than 100 Ω · cm) was subjected to finish polishing. Prior to the final polishing, rough polishing was performed on the silicon wafer in advance using a commercially available abrasive composition. The surface roughness (haze) of the silicon wafer after the rough polishing was 2.680 ppb.
（２−２）希釈研磨液組成物の所定の時間の保存が及ぼすシリコンウェーハ表面への影響
濃縮研磨液組成物の調製後、直ちに、濃縮研磨液組成物を、５Ｌ成型液体容器フジテーナー（登録商標）（藤森工業社製）に空気が入らいないように充填し、室温（２０〜２５度）で１４日間保存した後、濃縮研磨液組成物を４０倍に希釈して希釈研磨液組成物を得た。具体的には、濃縮研磨液組成物とイオン交換水との体積比が１：３９（イオン交換水：濃縮研磨液組成物）となるように、濃縮研磨液組成物をイオン交換水に添加し、これらの濃度が均一になるまでこれらを十分に撹拌（例えば５分間撹拌）することにより希釈研磨液組成物を得た。得られた希釈研磨液組成物を表１に示す様に所定の期間保存した後、直ちに、当該希釈研磨液組成物を、下記の研磨条件（（２−３）仕上げ研磨条件）の、シリコンウェーハ（直径２００ｍｍのシリコン片面鏡面ウェーハ、伝導型：Ｐ、結晶方位：１００、抵抗率０．１Ω・ｃｍ以上１００Ω・ｃｍ未満）の仕上げ研磨に用いた。当該仕上げ研磨に先立ってシリコンウェーハに対して市販の研磨剤組成物を用いてあらかじめ粗研磨を実施した。粗研磨を終了したシリコンウェーハの表面粗さ（ヘイズ）は、2.680ppbであった。尚、表１中の「希釈してからの日数（時間）」は、上記のとおり希釈研磨液組成物を得た直後から研磨機に供給されるまでに経過した時間（「所定の時間」）である。
(2-2) Influence on Storage of Silicon Wafer by Storage of Diluted Polishing Liquid Composition for Predetermined Time Immediately after the preparation of the concentrated polishing liquid composition, the concentrated polishing liquid composition is converted into a 5 L molded liquid container Fujitainer (registered trademark). ) (Made by Fujimori Kogyo Co., Ltd.) so that air does not enter, and after storing for 14 days at room temperature (20 to 25 degrees), the concentrated polishing composition is diluted 40 times to obtain a diluted polishing composition. It was. Specifically, the concentrated polishing liquid composition is added to the ion exchange water so that the volume ratio of the concentrated polishing liquid composition to the ion exchange water is 1:39 (ion exchange water: concentrated polishing liquid composition). The diluted polishing liquid composition was obtained by sufficiently stirring them (for example, stirring for 5 minutes) until these concentrations became uniform. After the obtained diluted polishing composition is stored for a predetermined period as shown in Table 1, the diluted polishing composition is immediately applied to a silicon wafer under the following polishing conditions ((2-3) final polishing conditions). This was used for finish polishing of a silicon single-sided mirror wafer having a diameter of 200 mm, conductivity type: P, crystal orientation: 100, resistivity of 0.1 Ω · cm to less than 100 Ω · cm. Prior to the final polishing, rough polishing was performed on the silicon wafer in advance using a commercially available abrasive composition. The surface roughness (haze) of the silicon wafer after the rough polishing was 2.680 ppb. In Table 1, “Days after dilution (hours)” is the time (“predetermined time”) that has passed since the diluted polishing composition was supplied to the polishing machine as described above. It is.
（２−３）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）
ウェーハ研磨圧力：１００ｇ/ｃｍ2
定盤回転速度：６０ｒｐｍ
研磨時間：１０分
研磨剤組成物の供給速度：２００ｍｌ/ｍｉｎ
研磨剤組成物の温度：２０℃
キャリア回転速度：６０ｒｐｍ
(2-3) Final polishing conditions Polisher: Single-sided 8-inch polishing machine GRIND-X SPP600s (manufactured by Okamoto)
Polishing pad: Suede pad (Toray Cortex, Asker hardness 64, thickness 1.37mm, nap length 450um, opening diameter 60um)
Wafer polishing pressure: 100 g / cm 2
Surface plate rotation speed: 60 rpm
Polishing time: 10 minutes Supply rate of the abrasive composition: 200 ml / min
Abrasive composition temperature: 20 ° C
Carrier rotation speed: 60rpm
（３）洗浄方法
仕上げ研磨後、シリコンウェーハに対して、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のオゾンを含んだ純水をノズルから流速1L/minで600rpmで回転するシリコンウェーハの中央に向かって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％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）を含んだ純水をノズルから流速1L/minで600rpmで回転するシリコンウェーハの中央に向かって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1500rpmでシリコンウェーハを回転させた。
(3) Cleaning method After finish polishing, the silicon wafer was subjected to ozone cleaning and diluted hydrofluoric acid cleaning as follows. In ozone cleaning, pure water containing 20 ppm ozone was sprayed from a nozzle toward the center of a silicon wafer rotating at 600 rpm at a flow rate of 1 L / min for 3 minutes. At this time, the temperature of the ozone water was normal temperature. Next, dilute hydrofluoric acid cleaning was performed. In dilute hydrofluoric acid cleaning, pure water containing 0.5% ammonium hydrogen fluoride (special grade: Nacalai Tex Co., Ltd.) was sprayed from the nozzle toward the center of the silicon wafer rotating at 600 rpm at a flow rate of 1 L / min for 6 seconds. The above ozone cleaning and dilute hydrofluoric acid cleaning were performed as a set, for a total of 2 sets, and finally spin drying was performed. In the spin drying, the silicon wafer was rotated at 1500 rpm.
（４）シリコンウェーハ表面の表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の評価
洗浄後のシリコンウェーハ表面の表面粗さ（ヘイズ）は、表面粗さ測定装置「Surfscan SP1」（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）の値を用いた。また、表面欠陥（ＬＰＤ）はＨａｚｅ測定時に同時に測定され、シリコンウェーハ表面上の粒径が５０ｎｍ以上のパーティクル数を測定することによって評価した。表面欠陥（ＬＰＤ）の数値が小さいほど表面欠陥が少ないことを示す。また、Ｈａｚｅ（ＤＷＯ）の数値が小さいほど表面の平滑性が高いことを示す。尚、濃縮研磨液組成物の保存時間が及ぼすシリコンウェーハ表面への影響を評価するにあたり、調製後３０日経た濃縮研磨液組成物を希釈して直ぐに研磨に使用した場合の表面欠陥（ＬＰＤ）及びＨａｚｅ（ＤＷＯ）の値を１．０（基準値）とし、下記評価基準により、表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の相対評価を行った。また、希釈研磨液組成物の所定の時間の保存が及ぼすシリコンウェーハ表面への影響を評価するにあたり、調製後１４日経た濃縮研磨液組成物を希釈して得た希釈研磨液組成物を直ぐに研磨に使用した場合の表面欠陥（ＬＰＤ）及びＨａｚｅ（ＤＷＯ）の値を１．０（基準値）とし、下記評価基準により、表面欠陥（ＬＰＤ）及び表面粗さ（ヘイズ）の相対評価を行った。
(4) Evaluation of surface defects (LPD) and surface roughness (haze) on the surface of a silicon wafer The surface roughness (haze) of a silicon wafer surface after cleaning is measured by a surface roughness measuring device “Surfscan SP1” (manufactured by KLA Tencor). The value of the dark field wide oblique incidence channel (DWO) measured using Further, the surface defect (LPD) was measured at the same time as the Haze measurement, and evaluated by measuring the number of particles having a particle diameter of 50 nm or more on the silicon wafer surface. It shows that there are few surface defects, so that the numerical value of a surface defect (LPD) is small. Moreover, it shows that the smoothness of a surface is so high that the numerical value of Haze (DWO) is small. In evaluating the influence of the storage time of the concentrated polishing liquid composition on the surface of the silicon wafer, surface defects (LPD) when the concentrated polishing liquid composition 30 days after preparation was diluted and immediately used for polishing, and The value of Haze (DWO) was set to 1.0 (reference value), and surface defects (LPD) and surface roughness (haze) were subjected to relative evaluation according to the following evaluation criteria. Moreover, in evaluating the influence on the silicon wafer surface that the storage of the diluted polishing liquid composition for a predetermined time has, the diluted polishing liquid composition obtained by diluting the concentrated polishing liquid composition 14 days after the preparation is immediately polished. The surface defect (LPD) and haze (DWO) values when used in the above were set to 1.0 (reference value), and relative evaluation of the surface defect (LPD) and surface roughness (haze) was performed according to the following evaluation criteria. .
＜評価基準＞
○：測定値が基準値１．０に対して、＋２０％以下
△：測定値が基準値１．０に対して、２０％を超え２００％以下
×：測定値が基準値１．０に対して、２００％を超える
<Evaluation criteria>
○: The measured value is + 20% or less with respect to the reference value of 1.0. Δ: The measured value is over 20% and less than 200% with respect to the reference value of 1.0. Over 200%
表１に示されるように、調製後、１４日以上経過した濃縮研磨液組成物を用いた場合、保存時間が１４日未満の濃縮研磨液組成物を用いた場合よりも、研磨されたシリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ(ヘイズ)は小さい。また、表１に示されるように、調製後１４日以上経た濃縮研磨液組成物を、希釈後２日以内にシリコンウェーハの研磨に使用した場合、希釈後２日を超えた後にシリコンウェーハの研磨に使用する場合よりも、研磨されたシリコンウェーハの表面欠陥（ＬＰＤ）及び表面粗さ(ヘイズ)は小さい。 As shown in Table 1, when a concentrated polishing liquid composition that has passed 14 days or more after preparation is used, the polished silicon wafer is more polished than when a concentrated polishing liquid composition having a storage time of less than 14 days is used. The surface defects (LPD) and surface roughness (haze) are small. In addition, as shown in Table 1, when a concentrated polishing composition that has passed 14 days or more after preparation is used for polishing a silicon wafer within 2 days after dilution, the silicon wafer is polished after 2 days after dilution. The surface defect (LPD) and the surface roughness (haze) of the polished silicon wafer are smaller than those used in the above.
本発明は、研磨されたシリコンウェーハ表面の表面粗さ（ヘイズ）及び表面欠陥（ＬＰＤ）を安定して低減可能とするので、半導体基板の量産において有用である。 The present invention can stably reduce the surface roughness (haze) and surface defects (LPD) of the polished silicon wafer surface, and is useful in mass production of semiconductor substrates.
Claims (5)
シリコンウェーハ用研磨液組成物は、シリカ粒子、水溶性高分子化合物、及び塩基性化合物を含み、
調製後１４日以上経た、前記シリコンウェーハ用研磨液組成物の濃縮液を、希釈後２日以内に前記被研磨シリコンウェーハの研磨に使用し、
前記シリコンウェーハ用研磨液組成物の濃縮液を希釈して得た前記シリコンウェーハ用研磨液組成物における、前記塩基性化合物の含有量が６０質量ｐｐｍ以上３００質量ｐｐｍ以下、前記水溶性高分子化合物の含有量が６０質量ｐｐｍ以上５２０質量ｐｐｍ以下である、半導体基板の製造方法。 A step of polishing a silicon wafer to be polished using the polishing composition for a silicon wafer,
The polishing composition for a silicon wafer includes silica particles, a water-soluble polymer compound, and a basic compound,
More than 14 days after preparation, the concentrated solution of the polishing composition for a silicon wafer is used for polishing the silicon wafer to be polished within 2 days after dilution,
In the polishing composition for a silicon wafer obtained by diluting a concentrated solution of the polishing composition for a silicon wafer, the content of the basic compound is 60 mass ppm or more and 300 mass ppm or less, and the water-soluble polymer compound. The manufacturing method of a semiconductor substrate whose content of is 60 mass ppm or more and 520 mass ppm or less.
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