JP2009032816A - Sodium hydroxide aqueous solution for silicon wafer etching - Google Patents
Sodium hydroxide aqueous solution for silicon wafer etching Download PDFInfo
- Publication number
- JP2009032816A JP2009032816A JP2007193733A JP2007193733A JP2009032816A JP 2009032816 A JP2009032816 A JP 2009032816A JP 2007193733 A JP2007193733 A JP 2007193733A JP 2007193733 A JP2007193733 A JP 2007193733A JP 2009032816 A JP2009032816 A JP 2009032816A
- Authority
- JP
- Japan
- Prior art keywords
- silicon wafer
- aqueous solution
- caustic soda
- sodium hydroxide
- etching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 title claims abstract description 123
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 28
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 28
- 239000010703 silicon Substances 0.000 title claims abstract description 28
- 239000007864 aqueous solution Substances 0.000 title claims abstract description 26
- 238000005530 etching Methods 0.000 title claims description 16
- 239000000243 solution Substances 0.000 claims abstract description 17
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 38
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 claims description 3
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 3
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 abstract description 28
- 229910052751 metal Inorganic materials 0.000 abstract description 14
- 239000002184 metal Substances 0.000 abstract description 14
- 229910052759 nickel Inorganic materials 0.000 abstract description 14
- 238000011109 contamination Methods 0.000 abstract description 7
- 235000012431 wafers Nutrition 0.000 description 22
- 239000012535 impurity Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 7
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 238000005868 electrolysis reaction Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- -1 and the like Substances 0.000 description 1
- 238000005341 cation exchange Methods 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
本発明は、シリコンウエハーをエッチングする際に、苛性ソーダ水溶液に含まれる金属不純物、特にニッケル不純物によるシリコンウエハーの汚染を防止することが可能な高機能の苛性ソーダ水溶液に関する。 The present invention relates to a high-performance caustic soda aqueous solution capable of preventing contamination of a silicon wafer by metal impurities, particularly nickel impurities, contained in the caustic soda aqueous solution when etching a silicon wafer.
近年、シリコンウエハーのエッチングは混酸（弗酸＋硝酸＋酢酸）から取り扱いのやさしい苛性アルカリ水溶液に転換が進もうとしている。特に、苛性ソーダ水溶液がシリコンウエハーの表面特性を改善し生産性を大幅に向上させるので好ましい。しかし、一般に、苛性ソーダ水溶液は、食塩の電解によって製造されるが一般的に数ｐｐｍの鉄分、ニッケル分などを含有しており、これら鉄分、ニッケルなど金属不純物分は、ウエハーエッチングするときにシリコンウエハーへ浸透して残存し、ウエハー電気絶縁特性を変化させる。 In recent years, the etching of silicon wafers has been changing from a mixed acid (hydrofluoric acid + nitric acid + acetic acid) to a caustic aqueous solution that is easy to handle. In particular, an aqueous caustic soda solution is preferable because it improves the surface characteristics of the silicon wafer and greatly improves productivity. However, in general, an aqueous caustic soda solution is produced by electrolysis of sodium chloride, but generally contains several ppm of iron, nickel, and the like, and metal impurities such as iron and nickel are removed when a silicon wafer is etched. Permeates into the residue and changes the electrical insulation properties of the wafer.
苛性ソーダ水溶液に含まれる金属不純物を除去し精製する方法として、特許文献１には、陽イオン交換膜を用いた苛性ソーダ水溶液の電解による精製方法が開示されている。この方法によれば、苛性ソーダ水溶液中の金属不純物濃度は１ｐｐｂ以下にできるとされている。また、特許文献２には水酸化ナトリウム中のニッケル濃度を０．１ｐｐｂ以下にすることでシリコンウエハーに残存するニッケル分などを低減できると開示している。しかし、この方法は食塩を電気分解して得た苛性ソーダ水溶液を再び電気分解して、苛性ソーダ水溶液の濃度を高めながら金属不純物を除去する方法であり精製効率が悪いという欠点がある。 As a method for removing and purifying metal impurities contained in an aqueous caustic soda solution, Patent Document 1 discloses a purification method by electrolysis of an aqueous caustic soda solution using a cation exchange membrane. According to this method, the metal impurity concentration in the aqueous caustic soda solution can be reduced to 1 ppb or less. Patent Document 2 discloses that the nickel content remaining on the silicon wafer can be reduced by setting the nickel concentration in the sodium hydroxide to 0.1 ppb or less. However, this method has a drawback that the purification efficiency is poor because the aqueous solution of caustic soda obtained by electrolyzing salt is electrolyzed again to remove metal impurities while increasing the concentration of the aqueous solution of caustic soda.
また、苛性ソーダ水溶液に含まれる金属不純物によるシリコンウエハーの汚染を防止するために、特許文献３では、苛性ソーダ水溶液に還元剤を添加して、金属不純物のイオン成分を不活性な金属に還元してエッチングに供するという方法が開示されている。この方法はエッチングに供する前に、イオン性の金属不純物を全て金属の不活性な状態に還元し、この状態をエッチングに供するまで維持しなければならないので、酸素の混入を防ぐために、窒素雰囲気下で貯蔵と搬送することを必要とし、さらに過剰の還元剤の添加が必要になるなどの欠点がある。
本発明は、こうした実情の下に、特別の管理や高度な精製を必要とせずに、シリコンウエハーのエッチング剤として使用できる高機能の苛性ソーダ水溶液を提供することを目的とするものである。 Under the circumstances, an object of the present invention is to provide a highly functional aqueous solution of caustic soda that can be used as an etchant for silicon wafers without requiring special management or advanced purification.
本発明者は鋭意検討した結果、アルカノールアミン類を苛性ソーダ水溶液に含有させることにより、シリコンウエハーをエッチングする際に、苛性ソーダ水溶液に微量含まれるニッケル不純物のシリコンウエハーへの浸透を高度に防止する能力をもつことを見出したことにより本発明に至った。
すなわち、本発明は、
（１）アルカノールアミン類を含有することを特徴とするシリコンウエハーエッチング用苛性ソーダ水溶液、
（２）アルカノールアミン類がトリエタノールアミン、ジエタノールアミンおよびモノエタノールアミンからなる群から選ばれる一種もしくは二種以上の混合物であることを特徴とする前記（１）記載のシリコンウエハーエッチング用苛性ソーダ水溶液、
（３）アルカノールアミン類の苛性ソーダ水溶液中の含有量が０．０１重量％以上であることを特徴とする前記（１）または（２）に記載のシリコンウエハーエッチング用苛性ソーダ水溶液、
である。
As a result of intensive studies, the present inventor has an ability to highly prevent the penetration of nickel impurities contained in a trace amount of the caustic soda aqueous solution into the silicon wafer when the silicon wafer is etched by adding the alkanolamines to the caustic soda aqueous solution. As a result, the present invention has been achieved.
That is, the present invention
(1) Caustic soda aqueous solution for silicon wafer etching, characterized by containing alkanolamines,
(2) The caustic soda aqueous solution for silicon wafer etching according to (1) above, wherein the alkanolamines are one or a mixture of two or more selected from the group consisting of triethanolamine, diethanolamine and monoethanolamine,
(3) The caustic soda aqueous solution for silicon wafer etching according to the above (1) or (2), wherein the content of the alkanolamines in the caustic soda aqueous solution is 0.01% by weight or more,
It is.
以上説明したようにように、本発明の苛性ソーダ水溶液でシリコンウエハーをエッチングするとニッケル汚染濃度の極めて低いシリコンウエハーを得ることができる。 As described above, when a silicon wafer is etched with the aqueous caustic soda solution of the present invention, a silicon wafer having a very low nickel contamination concentration can be obtained.
本発明において用いる原料苛性ソーダ水溶液は、食塩の電気分解により得られる３０〜５２重量％の水溶液が好ましい。また、この原料苛性ソーダ水溶液は鉄分、ニッケル分、クロム分、銅分、マンガン分などを数ｐｐｍから数ｐｐｂ含んでいる場合がある。好ましい原料苛性ソーダ水溶液は不純物の少ないより高純度の苛性ソーダ水溶液である。特に、ニッケル分と銅分は１０ｐｐｂ以下が好ましい。
本発明の苛性ソーダ水溶液は上記原料苛性ソーダ水溶液にアルカノールアミン類を含有してなるものである。
アルカノールアミン類の具体例としては、トリエタノールアミン、ジエタノールアミン、モノエタノールアミン等がある。苛性ソーダ水溶液が、これらの化合物からなる群から選ばれる化合物の一種もしくは二種以上の混合物を含有していることが好ましい。
The raw caustic soda aqueous solution used in the present invention is preferably a 30 to 52% by weight aqueous solution obtained by electrolysis of sodium chloride. Further, this raw material caustic soda aqueous solution may contain several ppm to several ppb of iron, nickel, chromium, copper, manganese and the like. A preferred raw caustic soda solution is a higher purity caustic soda solution with fewer impurities. In particular, the nickel content and the copper content are preferably 10 ppb or less.
The aqueous caustic soda solution of the present invention comprises the above raw caustic soda aqueous solution containing alkanolamines.
Specific examples of alkanolamines include triethanolamine, diethanolamine, and monoethanolamine. It is preferable that the aqueous caustic soda solution contains one or a mixture of two or more compounds selected from the group consisting of these compounds.
アルカノールアミン類の苛性ソーダ水溶液中の好ましい含有量は特に限定されないが、０．０１重量％以上で５重量％以下が好ましい。０．０１重量％以上のときに汚染を抑制する効果が高くなり、５重量％以下であると苛性ソーダ水溶液の物性に影響してエッチング性能を変化させることが少ないので好ましい。より好ましくは０．０５重量％〜２重量％である。 The preferred content of the alkanolamines in the aqueous caustic soda solution is not particularly limited, but is preferably 0.01% by weight or more and 5% by weight or less. When the amount is 0.01% by weight or more, the effect of suppressing contamination is high, and when the amount is 5% by weight or less, the physical properties of the aqueous caustic soda solution are affected and the etching performance is hardly changed, which is preferable. More preferably, it is 0.05 weight%-2 weight%.
以下に本発明の実施例を説明するが、本発明はこれに限定されるものではない。 Examples of the present invention will be described below, but the present invention is not limited thereto.
[実施例１〜５]
ニッケル分を２ｐｐｂ含む４８重量％苛性ソーダ水溶液に表１に示すアルカノールアミン類を含有させた苛性ソーダ水溶液を作成する。この苛性ソーダ水溶液１リットルをエッチング槽に入れて、ニッケルの不純物濃度が２×１０１１ａｔｏｍｓ／ｃｍ２、抵抗が０．０１Ωのポリッシングした２００ｍｍシリコンウエハーを８０℃で２分間エッチングし、水洗、フッ酸で洗浄した後、シリコンウエハーの金属不純物濃度を調べた。シリコンウエハー表面付近に含まれる金属不純物は表面を硝酸酸化して二酸化珪素とした後、フッ酸で溶解してＩＣＰ−ＭＳ(誘導結合プラズマ質量分析)法により分析した。
[Examples 1 to 5]
A caustic soda aqueous solution containing alkanolamines shown in Table 1 in a 48 wt% caustic soda aqueous solution containing 2 ppb of nickel is prepared. 1 liter of this caustic soda aqueous solution is put into an etching tank, and a polished 200 mm silicon wafer having a nickel impurity concentration of 2 × 10 11 atoms / cm 2 and a resistance of 0.01Ω is etched at 80 ° C. for 2 minutes, washed with water, and hydrofluoric acid. Then, the metal impurity concentration of the silicon wafer was examined. Metal impurities contained in the vicinity of the silicon wafer surface were oxidized with nitric acid to form silicon dioxide, dissolved in hydrofluoric acid, and analyzed by ICP-MS (inductively coupled plasma mass spectrometry).
[比較例１]
アルカノールアミン類を含まない、ニッケル分を２ｐｐｂ含む４８％重量％苛性ソーダ水溶液を用いて、実施例１記載の同様の方法を用いてシリコンウエハーをエッチングし、金属不純物濃度を調べた。
表１から分かるように、本発明の苛性ソーダ水溶液でシリコンウエハーをエッチングすることでニッケル汚染を大幅に抑制していることが分かる。
[Comparative Example 1]
The silicon wafer was etched using the same method described in Example 1 using a 48% wt% aqueous sodium hydroxide solution containing no alkanolamines and containing 2 ppb of nickel, and the metal impurity concentration was examined.
As can be seen from Table 1, it can be seen that nickel contamination is greatly suppressed by etching a silicon wafer with the aqueous caustic soda solution of the present invention.
本発明は半導体基板等に用いられるシリコンウエハーのエッチング剤として好適に利用することができる。 The present invention can be suitably used as an etching agent for silicon wafers used for semiconductor substrates and the like.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007193733A JP2009032816A (en) | 2007-07-25 | 2007-07-25 | Sodium hydroxide aqueous solution for silicon wafer etching |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007193733A JP2009032816A (en) | 2007-07-25 | 2007-07-25 | Sodium hydroxide aqueous solution for silicon wafer etching |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2009032816A true JP2009032816A (en) | 2009-02-12 |
Family
ID=40403042
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007193733A Pending JP2009032816A (en) | 2007-07-25 | 2007-07-25 | Sodium hydroxide aqueous solution for silicon wafer etching |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2009032816A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102732886A (en) * | 2011-04-01 | 2012-10-17 | 李康 | Matte manufacturing solution of solar energy single crystal silicon wafers and its preparation method |
| JP2014203835A (en) * | 2013-04-01 | 2014-10-27 | 株式会社トクヤマ | Composition for forming texture, method of manufacturing silicon substrate, and composition preparation kit for forming texture |
-
2007
- 2007-07-25 JP JP2007193733A patent/JP2009032816A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102732886A (en) * | 2011-04-01 | 2012-10-17 | 李康 | Matte manufacturing solution of solar energy single crystal silicon wafers and its preparation method |
| JP2014203835A (en) * | 2013-04-01 | 2014-10-27 | 株式会社トクヤマ | Composition for forming texture, method of manufacturing silicon substrate, and composition preparation kit for forming texture |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100974034B1 (en) | Cleaning composition and method of cleaning therewith | |
| JP6798045B2 (en) | Processing liquid for semiconductor wafers containing hypochlorite ions | |
| JP5854230B2 (en) | Substrate cleaning liquid and substrate cleaning method | |
| JP2017216444A (en) | Etchant | |
| JP2009032816A (en) | Sodium hydroxide aqueous solution for silicon wafer etching | |
| TW200517483A (en) | Cerium salt and fabricating method thereof, cerium oxide and cerium polishing agent | |
| JP2009032815A (en) | Sodium hydroxide aqueous solution for silicon wafer etching | |
| JP6327207B2 (en) | Method for cleaning Ge or SiGe or germanide | |
| JP3689871B2 (en) | Alkaline cleaning solution for semiconductor substrates | |
| JP2009029649A (en) | Aqueous solution of caustic soda for etching silicon wafer | |
| JP5220569B2 (en) | Silicon wafer etching agent and etching method using the same | |
| JPH01240683A (en) | Composition of etching solution for copper and etching method | |
| JP2006165408A (en) | Alkali etching liquid for silicon wafer and etching method using the same | |
| JP2005146358A (en) | Etching liquid for titanium or titanium alloy | |
| JP2009029650A (en) | Aqueous solution of caustic soda for etching silicon wafer | |
| WO2014010471A1 (en) | Etching fluid, etching force recovery agent, method for manufacturing semiconductor substrate for solar cell, and semiconductor substrate for solar cell | |
| JP2005310845A (en) | Method and liquid for processing substrate | |
| JP5220570B2 (en) | Silicon wafer etching agent and etching method using the same | |
| JP2006339509A (en) | Composition for etching metal titanium and etching method using it | |
| JP5017985B2 (en) | Resist removing composition and resist removing method | |
| JP2008050198A (en) | Method for producing high-purity alkali metal hydroxide | |
| KR101713598B1 (en) | Cleaning composition for removing silicon based scale | |
| WO2018104992A1 (en) | Ge, sige or germanide washing method | |
| CN110669594B (en) | Silicon carbide single crystal wafer cleaning agent and preparation method and application thereof | |
| JP2010272590A (en) | Silicon wafer etchant composed of high purity alkaline, and etching method using the same |