JPH05166781A - Cleaning method for silicon wafer - Google Patents

Cleaning method for silicon wafer

Info

Publication number
JPH05166781A
JPH05166781A JP35126091A JP35126091A JPH05166781A JP H05166781 A JPH05166781 A JP H05166781A JP 35126091 A JP35126091 A JP 35126091A JP 35126091 A JP35126091 A JP 35126091A JP H05166781 A JPH05166781 A JP H05166781A
Authority
JP
Japan
Prior art keywords
cleaning
liquid
silicon
less
purification
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.)
Granted
Application number
JP35126091A
Other languages
Japanese (ja)
Other versions
JP2893493B2 (en
Inventor
Etsuro Morita
悦郎 森田
Jiro Tatsuta
次郎 龍田
Mari Sakurai
真理 桜井
Yasushi Shimanuki
康 島貫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Silicon Corp
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Silicon Corp
Mitsubishi Materials Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
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Application filed by Mitsubishi Materials Silicon Corp, Mitsubishi Materials Corp filed Critical Mitsubishi Materials Silicon Corp
Priority to JP3351260A priority Critical patent/JP2893493B2/en
Publication of JPH05166781A publication Critical patent/JPH05166781A/en
Application granted granted Critical
Publication of JP2893493B2 publication Critical patent/JP2893493B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PURPOSE:To eliminate the necessity of oxygen cleaning in cleaning process and facilitate waste liquid treatment by using cleaning liquid containing ammonia hydrogen peroxide water in which the concentration of metallic impurities is less than a specific value. CONSTITUTION:Aqueous ammonia and hydrogen peroxide water are mixed in the prescribed concentration ratio, and are previously carried into a buffer tank 2 as cleaning liquid. Pure water is supplied in the buffer tank 2 through water supply pipe. The cleaning liquid is circulated through a cartridge-type refining section 4 having a silicon for gettering, and then through a refining section 5 equipped with a filter for adsorbing fine grains. Circulation of the cleaning liquid is repeated until the concentration of metallic impurities gets to less than 1ppt, and the number of fine grains of more than 0.1mum gets less than one cc. As a result, cleaning is made possible without oxygen cleaning. Accordingly, waste liquid treatment is facilitated.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、半導体シリコンウェー
ハの洗浄において、洗浄工程を簡略化し廃液処理の容易
な洗浄方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cleaning a semiconductor silicon wafer, which simplifies the cleaning process and facilitates waste liquid treatment.

【0002】[0002]

【従来技術とその課題】半導体シリコンウェーハの製造
時には種々の工程でシリコンウェーハが洗浄され、研磨
後に最終洗浄が行なわれる。一般的な洗浄工程は、(イ)
アンモニア過酸化水素水からなる洗浄液を用いてパーテ
イクル汚染の汚染源となる微粒子や有機物を洗浄除去
し、(ロ)純水でリンスした後に、(ハ)フッ酸で洗浄して
鉄、亜鉛、アルミニウム等の金属汚染物を除去し、(ニ)
純水でリンスした後に、(ホ)塩酸過酸化水素水からなる
洗浄液を用いて銅等の重金属汚染物を除去している。従
来の洗浄工程でアルカリ系洗浄と酸系洗浄を組合わせて
行なう理由は、アンモニア系洗浄では汚染源の微粒子を
洗浄除去できるもののウェーハ表面に金属不純物が付着
し易くなり金属汚染源を除去できず、また一方、酸系洗
浄は金属汚染源を除去できるものの微粒子汚染には効果
が低いためである。
2. Description of the Related Art When manufacturing a semiconductor silicon wafer, the silicon wafer is cleaned in various steps, and a final cleaning is performed after polishing. The general cleaning process is (a)
Fine particles and organic substances that are the source of particle contamination are washed and removed using a cleaning solution consisting of ammonia hydrogen peroxide solution, (b) rinsed with pure water, and then (c) washed with hydrofluoric acid to remove iron, zinc, aluminum, etc. Remove the metal contaminants of (d)
After rinsing with pure water, heavy metal contaminants such as copper are removed by using a cleaning solution composed of (e) hydrochloric acid hydrogen peroxide solution. The reason why the alkaline cleaning and the acid cleaning are combined in the conventional cleaning process is that ammonia-based cleaning can clean and remove fine particles as a contamination source, but metal impurities easily adhere to the wafer surface and the metal contamination source cannot be removed. On the other hand, the acid-based cleaning can remove the metal contamination source, but is not effective for the contamination of fine particles.

【0003】このように従来の洗浄工程ではアルカリ系
洗浄と酸系洗浄を組合わせて実施しているが、両工程は
相反する液質の洗浄液を用いるため、両工程を完全に分
離する必要があり設備が大型化し、かつ工程の管理も難
しいという問題がある。さらに各洗浄工程から排出され
る廃液処理も問題となっている。一方、洗浄液中の不純
物除去に関し、フッ酸洗浄液をシリコン粉末に接触させ
て液中の銅などの金属イオンをシリコン粉末に吸着させ
て精製した後に、シリコンウェーハを洗浄する方法が知
られている(特開平3-102827号)が、フッ酸によるシリコ
ンウェーハの洗浄だけでは微粒子汚染を除去することが
できない。
As described above, in the conventional cleaning process, the alkaline cleaning and the acid cleaning are performed in combination. However, since the cleaning liquids of the opposite quality are used in both processes, it is necessary to completely separate the both processes. There is a problem that equipment becomes large and process management is difficult. Furthermore, the treatment of waste liquid discharged from each cleaning step is also a problem. On the other hand, regarding the removal of impurities in the cleaning liquid, there is known a method of cleaning a silicon wafer after bringing a hydrofluoric acid cleaning liquid into contact with silicon powder to adsorb metal ions such as copper in the liquid to the silicon powder for purification. In JP-A-3-102827), it is not possible to remove fine particle contamination only by cleaning a silicon wafer with hydrofluoric acid.

【0004】[0004]

【発明の解決課題】本発明は、従来のシリコンウェーハ
洗浄における上記問題を解決した洗浄方法を提供するこ
とを目的とする。本発明においてシリコンウェーハの金
属汚染の状態を検討したところ、アンモニア過酸化水素
水による洗浄では、洗浄液中の金属不純物濃度が1ppb
程度のレベルであるときには、金属汚染を除去すること
はできず、場合によってはウェーハ表面の金属不純物濃
度が高くなるが、洗浄液中の金属不純物濃度が10ppt 以
下のレベルであるときは、酸系洗浄を行なわずにアンモ
ニア過酸化水素水の単独洗浄によっても、ウェーハ表面
の金属不純物濃度は増加せず、むしろ減少する傾向のあ
ることが見出だされた。従来、アンモニア過酸化水素水
を用いたアルカリ系洗浄だけではウェーハ表面に金属不
純物が吸着され易くなり不純物濃度は高くなると考えら
れており、上記知見はこのような従来の通念に対して予
想外のものであった。本発明は上記知見に基づき、金属
不純物濃度を10ppt以下、好ましくは1ppt以下、にした
アンモニア過酸化水素水を用いて洗浄することにより、
従来の酸系洗浄を不要にし洗浄工程を簡略化すると共に
廃液処理を容易にしたものである。
SUMMARY OF THE INVENTION It is an object of the present invention to provide a cleaning method which solves the above problems in conventional silicon wafer cleaning. When the state of metal contamination of the silicon wafer was examined in the present invention, it was found that the concentration of metal impurities in the cleaning liquid was 1 ppb in the cleaning with ammonia hydrogen peroxide solution.
At a moderate level, metal contamination cannot be removed, and the concentration of metal impurities on the wafer surface increases in some cases.However, when the concentration of metal impurities in the cleaning solution is 10 ppt or less, acid cleaning It was found that the concentration of metal impurities on the wafer surface does not increase, but rather tends to decrease, even if the ammonia hydrogen peroxide solution alone is cleaned without performing. Conventionally, it has been considered that metal impurities are likely to be adsorbed on the wafer surface and the impurity concentration is increased only by alkaline cleaning using ammonia hydrogen peroxide solution, and the above findings are unexpected against such conventional wisdom. It was a thing. The present invention is based on the above findings, by washing with ammonia hydrogen peroxide solution having a metal impurity concentration of 10 ppt or less, preferably 1 ppt or less,
This eliminates the need for conventional acid-based cleaning, simplifies the cleaning process, and facilitates waste liquid treatment.

【0005】[0005]

【課題の解決手段:発明の構成】本発明によれば、金属
不純物の濃度が10ppt以下、好ましくは1ppt以下、のア
ンモニア過酸化水素水からなる洗浄液を用いることによ
り酸系洗浄を省略したシリコンウェーハの洗浄方法が提
供される。また本発明によれば、シリコンウェーハの洗
浄系に、洗浄液を精製して該洗浄系に戻す精製循環ユニ
ットを付設し、該精製循環ユニットには金属不純物を吸
着するゲッタ用シリコンを設けた精製部と微粒子吸着用
フィルターを設けた精製部とを設け、洗浄液を洗浄系か
ら精製循環ユニットに導入し、液中の金属不純物と微粒
子を各々該ゲッタ用シリコンまたはフィルターに吸着さ
せて除去することにより金属不純物濃度を1ppt 以下に
精製し、再び洗浄系に戻してシリコンウェーハを洗浄す
る方法が提供される。更に本発明によれば、洗浄液を洗
浄槽に供給する際、該洗浄液の供給路に精製循環ユニッ
トを設け、該精製循環ユニットには金属不純物を吸着す
るゲッタ用シリコンを設けた精製部と微粒子吸着用フィ
ルターを設けた精製部とを設け、洗浄液を洗浄槽に供給
する前に予め上記精製循環ユニットに導入し、液中の金
属不純物と微粒子を各々該ゲッタ用シリコンまたはフィ
ルターに吸着させて除去することにより金属不純物濃度
を1ppt 以下に精製した後に洗浄槽に供給する洗浄方法
が提供される。
According to the present invention, a silicon wafer in which acid cleaning is omitted by using a cleaning solution composed of ammonia hydrogen peroxide solution having a metal impurity concentration of 10 ppt or less, preferably 1 ppt or less. A cleaning method is provided. Further, according to the present invention, a purification system in which a cleaning system for purifying a cleaning liquid and returning the cleaning liquid to the cleaning system is attached to the cleaning system for silicon wafers, and the purification circulation unit is provided with getter silicon for adsorbing metal impurities. And a purification unit provided with a filter for adsorbing fine particles, and introducing the cleaning liquid from the cleaning system into the purification circulation unit to remove metal impurities and fine particles in the liquid by adsorbing them on the getter silicon or filter respectively to remove the metal. There is provided a method of purifying an impurity concentration to 1 ppt or less and returning to a cleaning system again to clean a silicon wafer. Further, according to the present invention, when the cleaning liquid is supplied to the cleaning tank, a purification circulation unit is provided in the cleaning liquid supply path, and the purification circulation unit is provided with a getter silicon for adsorbing metal impurities and a fine particle adsorption unit. And a purifying section provided with a filter for supplying the cleaning liquid to the cleaning circulation unit in advance before supplying the cleaning liquid to the cleaning tank, and removes metal impurities and fine particles in the liquid by adsorbing to the getter silicon or the filter, respectively. This provides a cleaning method in which the metal impurity concentration is purified to 1 ppt or less and then supplied to the cleaning tank.

【0006】アンモニア過酸化水素水[H2O:H2O2:NH4OH
=5:1:0.25、液温80℃]に金属不純物としてFeイオンを
各々 1ppt、10ppt、1ppb添加した洗浄液にシリコンウ
ェーハを10分間浸漬してウェーハを洗浄し、ウェーハ表
面に付着しているFeイオン濃度を測定したところ図1の
結果が得られた。図示するように、洗浄液のFeイオン濃
度が1ppb の場合(試料No.1)には洗浄後のウェーハ表面
のFe濃度は何れも増加しており、金属不純物を洗浄除去
する効果は認められない。一方、洗浄液のFeイオン濃度
が1ppt、10pptの場合(試料No.2,3)には洗浄後のウェー
ハ表面のFe濃度は何れも減少し、各々109(atoms/cm2)
以下、1010(atoms/cm2)以下であり洗浄効果が明らか
に認められる。従ってウェーハ表面の金属不純物濃度が
109(atoms/cm2)レベル以下の洗浄効果が求められる場
合には酸系洗浄を行なう必要がない。また微粒子汚染に
ついてみると、試料No.2,3のウェーハ表面(6インチ径)に付
着している微粒子は0.1μm以上のものが表面全体で10個
以下であり、本来の微粒子洗浄効果にも優れている。
Ammonia hydrogen peroxide solution [H 2 O: H 2 O 2 : NH 4 OH
= 5: 1: 0.25, liquid temperature 80 ℃] Fe was adhering to the wafer surface by immersing the silicon wafer in a cleaning solution containing Fe ions as metal impurities at 1 ppt, 10 ppt, and 1 ppb for 10 minutes to clean the wafer. When the ion concentration was measured, the results shown in FIG. 1 were obtained. As shown in the figure, when the Fe ion concentration of the cleaning liquid is 1 ppb (Sample No. 1), the Fe concentration on the wafer surface after cleaning is increased, and the effect of cleaning and removing metal impurities is not recognized. On the other hand, when the Fe ion concentration of the cleaning liquid is 1 ppt and 10 ppt (Sample Nos. 2 and 3), the Fe concentration on the wafer surface after cleaning is reduced to 10 9 (atoms / cm 2 ) each.
Below 10 10 (atoms / cm 2 ), the cleaning effect is clearly recognized. Therefore, when the cleaning effect of the metal impurity concentration on the wafer surface of 10 9 (atoms / cm 2 ) level or less is required, it is not necessary to perform the acid cleaning. Regarding particulate contamination, the number of fine particles adhering to the wafer surface (6 inch diameter) of sample Nos. 2 and 3 was 0.1 μm or more on the entire surface, and 10 or less on the entire surface. Are better.

【0007】最近、64メカ゛以上の高集積用シリコンウェ
ーハが求められているが、この場合のウェーハ表面の金
属不純物濃度は109(atoms/cm2)程度である。本発明の
洗浄方法によれば、洗浄液として、金属不純物濃度が1
ppt以下のアンモニア過酸化水素水を用いた単独洗浄に
より目的の洗浄効果が得られ、従来のようなフッ酸や塩
酸過酸化水素水などを用いた酸系洗浄を更に行なう必要
がない。
Recently, there has been a demand for highly integrated silicon wafers of 64 mech or more. In this case, the concentration of metal impurities on the wafer surface is about 10 9 (atoms / cm 2 ). According to the cleaning method of the present invention, the cleaning liquid has a metal impurity concentration of 1
The intended cleaning effect can be obtained by single cleaning with ammonia hydrogen peroxide solution of ppt or less, and it is not necessary to further perform conventional acid cleaning using hydrofluoric acid or hydrochloric acid hydrogen peroxide solution.

【0008】本発明の洗浄方法に使用する過酸化水素水
およびアンモニア水は市販の30vol%濃度のものを使用
し、アンモニアと過酸化水素の組成は、H2O2:NH4OH=1:
0.25〜1:0.5を基準とし、水に対する過酸化水素の濃度
を5〜0.05%の範囲で調整すればよい。洗浄液の温度は5
0〜90℃が好ましい。液温が50℃より低いと洗浄時間が
長くなる。また液温が90℃より高いと薬液の分解が速く
必要な液組成を維持するのが難しくなるので好ましくな
い。洗浄時間は1〜20分程度でよい。
The hydrogen peroxide solution and the ammonia solution used in the cleaning method of the present invention are commercially available with a concentration of 30 vol%, and the composition of ammonia and hydrogen peroxide is H 2 O 2 : NH 4 OH = 1:
Based on 0.25 to 1: 0.5, the concentration of hydrogen peroxide with respect to water may be adjusted within the range of 5 to 0.05%. The temperature of the cleaning solution is 5
0 to 90 ° C is preferable. If the liquid temperature is lower than 50 ° C, the washing time will be longer. On the other hand, if the liquid temperature is higher than 90 ° C., the chemical liquid decomposes quickly and it becomes difficult to maintain the necessary liquid composition, which is not preferable. The cleaning time may be about 1 to 20 minutes.

【0009】次に、本発明に係る洗浄工程の一例を図2
に示す。洗浄工程には洗浄液を供給する供給部20、洗浄
槽1、水洗槽9、乾燥部10が設けられている。供給部20に
は、アンモニア水と過酸化水素水を混合した洗浄液から
汚染金属と微粒子を除去するための精製循環ユニットA
が付設されている。更に洗浄槽1には洗浄槽から溢流し
た洗浄液を精製するための同様の精製循環ユニットBが
付設されている。これら精製循環ユニットA,Bには、
金属不純物を吸着除去するためのゲッタ用シリコンを有
するカートリッジ型の金属不純物精製部4,6と微粒子を
吸着除去するフィルターを具えた微粒子精製部5,7が設
けられている。アンモニア水と過酸化水素水は所定の濃
度比(例えばH2O2:NH4OH=1:0.5)に混合され洗浄液として
予めバッファータンク2に導入される。またバッファー
タンク2には純水が給水管路(図示せず)を通じて供給さ
れる。次いで該洗浄液は精製循環ユニットAに導入され
金属不純物と微粒子が除去される。すなわち洗浄液はゲ
ッタ用シリコンを有するカートリッジ型の精製部4およ
び微粒子吸着用フィルターを具えた精製部5を経由し弁1
1を経て再びバッファタンク2に循環される。この洗浄液
の循環は金属不純物濃度および微粒子数が設定値(例え
ば金属不純物1ppt以下、微粒子0.1μm以上のものが1個/
cc)以下になるまで繰返される。金属不純物濃度および
微粒子数が設定値以下になった洗浄液はバルブ12を開い
て洗浄槽1に供給され、シリコンウェーハの洗浄が行な
われる。洗浄槽1では、ウェーハから除去された金属不
純物や微粒子が再びウェーハ表面に付着しないように洗
浄液が精製循環ユニットBに導かれ精製される。すなわ
ち洗浄槽1から溢流した洗浄液はゲッタ用シリコンを有
するカートリッジ型の精製部6に導かれ、金属不純物が
ゲッタ用シリコンによって吸着除去された後に微粒子吸
着用フィルターを具えた精製部7に導入されここで微粒
子が除去された後に再び洗浄槽1に循環される。洗浄さ
れたシリコンウェーハは水洗槽9で純水を用いて洗浄し
た後に乾燥部10に送られる。なお精製ユニットAを設け
ずに精製ユニットBだけでも金属不純物や微粒子を設定
値以下に除去することは可能であるが、精製ユニットA
を設けた場合に比べて精製時間が長引く。上記精製循環
ユニットA,Bのゲッタ用シリコンは着脱自在に設ける
とよい。また形状は板状、粒子状ないしブロック状の何
れでもよい。ゲッタ用シリコンにはフッ酸処理して表面
の不純物濃度を109/cm2以下にしたものが用いられる。
このゲッタ用シリコンに回収した洗浄液を接触させるこ
とにより洗浄液中の鉄、亜鉛、アルミニウムなどの不純
物金属イオンがゲッタ用シリコンの表面に吸着され除去
される。
Next, an example of the cleaning process according to the present invention is shown in FIG.
Shown in. In the cleaning process, a supply unit 20 for supplying a cleaning liquid, a cleaning tank 1, a water cleaning tank 9, and a drying unit 10 are provided. The supply unit 20 includes a purification circulation unit A for removing contaminant metals and fine particles from a cleaning liquid obtained by mixing ammonia water and hydrogen peroxide water.
Is attached. Further, the cleaning tank 1 is provided with a similar purification circulation unit B for purifying the cleaning liquid overflowing from the cleaning tank. These refining circulation units A and B include
There are provided cartridge type metal impurity refining units 4 and 6 having getter silicon for adsorbing and removing metal impurities, and fine particle refining units 5 and 7 having filters for adsorbing and removing fine particles. Ammonia water and hydrogen peroxide water are mixed in a predetermined concentration ratio (for example, H 2 O 2 : NH 4 OH = 1: 0.5) and introduced into the buffer tank 2 in advance as a cleaning liquid. Pure water is supplied to the buffer tank 2 through a water supply pipe (not shown). Next, the cleaning liquid is introduced into the purification circulation unit A to remove metal impurities and fine particles. That is, the cleaning liquid is passed through the cartridge type purifying unit 4 having getter silicon and the purifying unit 5 having a filter for adsorbing fine particles to the valve 1
After passing through 1, it is circulated to the buffer tank 2 again. The circulation of this cleaning liquid is such that the concentration of metal impurities and the number of fine particles are set values (for example, metal impurities of 1 ppt or less and fine particles of 0.1 μm or more per piece /
It is repeated until it becomes below cc). The cleaning liquid in which the metal impurity concentration and the number of fine particles have become equal to or less than the set values is supplied to the cleaning tank 1 by opening the valve 12 and the silicon wafer is cleaned. In the cleaning tank 1, the cleaning liquid is guided to the purification circulation unit B and purified so that the metal impurities and fine particles removed from the wafer do not adhere to the wafer surface again. That is, the cleaning liquid overflowing from the cleaning tank 1 is guided to a cartridge-type purification unit 6 having getter silicon, and after metal impurities are adsorbed and removed by the getter silicon, it is introduced to a purification unit 7 equipped with a particulate adsorption filter. After the particles are removed here, the particles are circulated again in the cleaning tank 1. The washed silicon wafer is washed with pure water in the washing tank 9 and then sent to the drying unit 10. Although it is possible to remove metal impurities and fine particles below a set value by using only the purification unit B without providing the purification unit A, the purification unit A
Purification time is prolonged as compared with the case where is provided. The gettering silicon of the refining circulation units A and B may be detachably provided. The shape may be plate-like, particle-like or block-like. The gettering silicon used is hydrofluoric acid treated to have a surface impurity concentration of 10 9 / cm 2 or less.
By contacting the collected cleaning liquid with the getter silicon, impurity metal ions such as iron, zinc, and aluminum in the cleaning liquid are adsorbed on the surface of the getter silicon and removed.

【0010】[0010]

【実施例】金属不純物濃度1pptのアンモニア過酸化水
素水[H2O:H2O2:NH4OH=5:1:0.25、液温70℃]に、表面
の金属不純物濃度が Al=1011,Fe=1011atoms/cm2のシリ
コンウェーハを10分間浸漬し、ウェーハ表面を洗浄した
ところ、AlおよびFeの不純物濃度が何れも109(atoms/cm
2)に低下し優れた洗浄効果が得られた(試料No.10)。一
方、比較のため同一の金属不純物濃度を有するシリコン
ウェーハについて従来のアルカリ系洗浄と酸系洗浄を行
なった。まず、上記シリコンウェーハを従来のアルカリ
系洗浄液(H2O:H2O2:NH4OH=5:1:1)に10分間浸漬して洗浄
した(試料No.11)。更に上記アルカリ系洗浄の後にフッ
酸(H2O:HF=100:1)に1分間浸漬した後に純水でリンス
し、塩酸過酸化水素水[H2O:H2O2:HCl=5:1:1]に10分間
浸漬した後、純水でリンスした(試料No.12)。この結果
を図3に示した。図示するように、洗浄後のウェーハ表
面のFe、Al濃度は本発明の洗浄方法を行なったものに比
べて何れも高く、本発明の洗浄効果に及ばなかった。
[Examples] Ammonia hydrogen peroxide solution with a metal impurity concentration of 1 ppt [H 2 O: H 2 O 2 : NH 4 OH = 5: 1: 0.25, liquid temperature 70 ° C] has a metal impurity concentration of Al = 10 on the surface. A silicon wafer of 11 , Fe = 10 11 atoms / cm 2 was dipped for 10 minutes and the wafer surface was cleaned, and the impurity concentrations of Al and Fe were both 10 9 (atoms / cm 2
2 ), and an excellent cleaning effect was obtained (Sample No. 10). On the other hand, for comparison, silicon wafers having the same metal impurity concentration were subjected to conventional alkaline cleaning and acid cleaning. First, the silicon wafer was immersed in a conventional alkaline cleaning solution (H 2 O: H 2 O 2 : NH 4 OH = 5: 1: 1) for 10 minutes for cleaning (Sample No. 11). Further, after the above alkaline cleaning, it is immersed in hydrofluoric acid (H 2 O: HF = 100: 1) for 1 minute, rinsed with pure water, and hydrochloric acid hydrogen peroxide solution [H 2 O: H 2 O 2 : HCl = 5 : 1: 1] for 10 minutes and then rinsed with pure water (Sample No. 12). The result is shown in FIG. As shown in the figure, the Fe and Al concentrations on the wafer surface after cleaning were both higher than those when the cleaning method of the present invention was performed, and did not reach the cleaning effect of the present invention.

【0011】[0011]

【発明の効果】本発明の洗浄方法によれば、酸系洗浄を
行なわなくてもアンモニア過酸化水素水による単独洗浄
だけで金属汚染と微粒子汚染を効果的に除去することが
でき、洗浄工程が大幅に簡略化されると共に酸系洗浄を
行なわないので廃液処理も容易である。
According to the cleaning method of the present invention, it is possible to effectively remove metal contamination and fine particle contamination only by single cleaning with ammonia hydrogen peroxide solution without performing acid-based cleaning. Since it is greatly simplified and the acid cleaning is not performed, waste liquid treatment is easy.

【図面の簡単な説明】[Brief description of drawings]

【図1】洗浄液中のFeイオン濃度と洗浄後のウェーハ表
面のFe濃度との関係を示すグラフ。
FIG. 1 is a graph showing a relationship between Fe ion concentration in a cleaning liquid and Fe concentration on a wafer surface after cleaning.

【図2】本発明の洗浄工程を示す概略工程図。FIG. 2 is a schematic process diagram showing a cleaning process of the present invention.

【図3】本発明の実施例と比較例の洗浄効果を示すグラ
フ。
FIG. 3 is a graph showing the cleaning effect of an example of the present invention and a comparative example.

【符号の説明】[Explanation of symbols]

1−洗浄槽、 2−バッファータンク、 4,6−金属不純物
精製部、 5,7−微粒子精製部、 9−水洗槽、10−乾燥
部、 11,12-弁、 20−供給部、A、B−精製循環ユニッ
1-wash tank, 2-buffer tank, 4,6-metal impurity purification section, 5,7-fine particle purification section, 9-water washing tank, 10-drying section, 11,12-valve, 20-supply section, A, B-Purification circulation unit

───────────────────────────────────────────────────── フロントページの続き (72)発明者 桜井 真理 埼玉県大宮市北袋町1丁目297番地 三菱 マテリアル株式会社中央研究所内 (72)発明者 島貫 康 東京都千代田区岩本町3−8−16 三菱マ テリアルシリコン株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mari Sakurai 1-297 Kitabukuro-cho, Omiya City, Saitama Mitsubishi Materials Corporation Central Research Laboratory (72) Inventor Yasushi Shimanuki 3-8-16 Iwamoto-cho, Chiyoda-ku, Tokyo Mitsubishi Material Silicon Co., Ltd.

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 金属不純物の濃度が10ppt以下、好まし
くは1ppt以下、のアンモニア過酸化水素水からなる洗
浄液を用いることにより酸系洗浄を省略したシリコンウ
ェーハの洗浄方法。
1. A method for cleaning a silicon wafer, wherein acid-based cleaning is omitted by using a cleaning solution containing ammonia hydrogen peroxide solution having a metal impurity concentration of 10 ppt or less, preferably 1 ppt or less.
【請求項2】 シリコンウェーハの洗浄系に、洗浄液を
精製して該洗浄系に戻す精製循環ユニットを付設し、該
精製循環ユニットには金属不純物を吸着するゲッタ用シ
リコンを設けた精製部と微粒子吸着用フィルターを設け
た精製部とを設け、洗浄液を洗浄系から精製循環ユニッ
トに導入し、液中の金属不純物と微粒子を各々該ゲッタ
用シリコンまたはフィルターに吸着させて除去すること
により金属不純物濃度を1ppt 以下に精製し、再び洗浄
系に戻してシリコンウェーハを洗浄する請求項1の洗浄
方法。
2. A silicon wafer cleaning system is further provided with a purification circulation unit for purifying a cleaning liquid and returning it to the cleaning system, and the purification circulation unit is provided with a getter silicon for adsorbing metal impurities and a fine particle. A purification unit provided with an adsorption filter is provided, and the cleaning liquid is introduced from the cleaning system to the purification circulation unit, and the metal impurities and fine particles in the liquid are adsorbed to the getter silicon or the filter to remove the impurities, respectively. The cleaning method according to claim 1, wherein the silicon wafer is purified by refining to less than 1 ppt and returning to the cleaning system again.
【請求項3】 洗浄液を洗浄槽に供給する際、該洗浄液
の供給路に精製循環ユニットを設け、該精製循環ユニッ
トには金属不純物を吸着するゲッタ用シリコンを設けた
精製部と微粒子吸着用フィルターを設けた精製部とを設
け、洗浄液を洗浄槽に供給する前に予め上記精製循環ユ
ニットに導入し、液中の金属不純物と微粒子を各々該ゲ
ッタ用シリコンまたはフィルターに吸着させて除去する
ことにより金属不純物濃度を1ppt 以下に精製した後に
洗浄槽に供給する請求項1の洗浄方法。
3. A purification section provided with a purification circulation unit in the supply path of the cleaning fluid when the cleaning fluid is supplied to the cleaning tank, and a purification section provided with getter silicon for adsorbing metal impurities and a particulate adsorption filter. By providing a purifying section provided with, by introducing the cleaning liquid in advance into the above-mentioned purification circulation unit before supplying the cleaning liquid to the cleaning tank, by adsorbing and removing metal impurities and fine particles in the liquid to the getter silicon or filter, respectively. The cleaning method according to claim 1, wherein the metal impurity concentration is purified to 1 ppt or less and then supplied to the cleaning tank.
JP3351260A 1991-12-13 1991-12-13 Silicon wafer cleaning method Expired - Fee Related JP2893493B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3351260A JP2893493B2 (en) 1991-12-13 1991-12-13 Silicon wafer cleaning method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3351260A JP2893493B2 (en) 1991-12-13 1991-12-13 Silicon wafer cleaning method

Publications (2)

Publication Number Publication Date
JPH05166781A true JPH05166781A (en) 1993-07-02
JP2893493B2 JP2893493B2 (en) 1999-05-24

Family

ID=18416118

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP2893493B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6214126B1 (en) 1993-11-15 2001-04-10 Matsushita Electric Industrial Co., Ltd. Method for cleaning a silicon substrate
JP2020113577A (en) * 2019-01-08 2020-07-27 東京エレクトロン株式会社 Substrate processing apparatus, substrate processing method, and storage medium

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62252141A (en) * 1986-04-24 1987-11-02 Kyushu Denshi Kinzoku Kk Cleanser for silicon semiconductor substrate
JPH03102827A (en) * 1989-09-18 1991-04-30 Hitachi Ltd Etching method for hf chemical

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62252141A (en) * 1986-04-24 1987-11-02 Kyushu Denshi Kinzoku Kk Cleanser for silicon semiconductor substrate
JPH03102827A (en) * 1989-09-18 1991-04-30 Hitachi Ltd Etching method for hf chemical

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6214126B1 (en) 1993-11-15 2001-04-10 Matsushita Electric Industrial Co., Ltd. Method for cleaning a silicon substrate
JP2020113577A (en) * 2019-01-08 2020-07-27 東京エレクトロン株式会社 Substrate processing apparatus, substrate processing method, and storage medium

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