JP2888217B2 - Method for controlling concentration of cleaning chemical solution and silicon wafer cleaning apparatus - Google Patents
Method for controlling concentration of cleaning chemical solution and silicon wafer cleaning apparatusInfo
- Publication number
- JP2888217B2 JP2888217B2 JP33220696A JP33220696A JP2888217B2 JP 2888217 B2 JP2888217 B2 JP 2888217B2 JP 33220696 A JP33220696 A JP 33220696A JP 33220696 A JP33220696 A JP 33220696A JP 2888217 B2 JP2888217 B2 JP 2888217B2
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- Japan
- Prior art keywords
- concentration
- hydrogen peroxide
- ammonia
- cleaning
- ratio
- 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.)
- Expired - Lifetime
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Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体製造プロセ
スにおいてシリコンウェハの洗浄に用いられる薬液、す
なわちアンモニアと過酸化水素との混合水溶液の濃度の
管理方法および、こういった薬液を用いたシリコンウェ
ハ洗浄装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the concentration of a chemical used for cleaning a silicon wafer in a semiconductor manufacturing process, that is, a method for controlling the concentration of a mixed aqueous solution of ammonia and hydrogen peroxide, and a silicon wafer using such a chemical. The present invention relates to a cleaning device.
【０００２】[0002]
【従来の技術】シリコンウェハの洗浄装置では、純水、
アンモニア水および過酸化水素水といった薬液を混合し
た洗浄液を６０℃程度まで加熱してシリコンウェハの洗
浄を行っている。洗浄装置の洗浄槽内の各薬液の濃度
は、それらの蒸発や分解等によって減少する方向で経時
的に変化する。薬液の濃度が変動すると、洗浄特性等が
低下し、シリコンウェハの歩留り低下の原因となる。2. Description of the Related Art In a silicon wafer cleaning apparatus, pure water,
A cleaning liquid in which a chemical solution such as ammonia water and hydrogen peroxide solution is mixed is heated to about 60 ° C. to clean the silicon wafer. The concentration of each chemical solution in the cleaning tank of the cleaning device changes with time in a decreasing direction due to their evaporation and decomposition. When the concentration of the chemical solution fluctuates, the cleaning characteristics and the like are reduced, which causes a reduction in the yield of silicon wafers.
【０００３】従来の洗浄装置は、図６に示すように、ア
ンモニア水が貯えられたアンモニア秤量槽１０５と、過
酸化水素水が貯えられた過酸化水素秤量槽１０６と、純
水が貯えられた純水秤量槽１０７とを有し、これらアン
モニア秤量槽１０５、過酸化水素秤量槽１０６および純
水秤量槽１０７からそれぞれアンモニア水、過酸化水素
水および純水を、それぞれポンプ１０８，１０９，１１
０の駆動により必要な量だけ洗浄槽１０１に供給し、洗
浄槽１０１内でシリコンウェハの洗浄を行う。そして、
アンモニア水および過酸化水素水は、それぞれ一定の時
間間隔で一定量だけ自動的に洗浄槽１０１に補充され
る。As shown in FIG. 6, the conventional cleaning apparatus includes an ammonia weighing tank 105 storing ammonia water, a hydrogen peroxide weighing tank 106 storing hydrogen peroxide water, and pure water. A pure water weighing tank 107 is provided. Ammonia water, hydrogen peroxide water, and pure water are supplied from the ammonia weighing tank 105, the hydrogen peroxide weighing tank 106, and the pure water weighing tank 107, respectively, to pumps 108, 109, and 11, respectively.
A necessary amount is supplied to the cleaning tank 101 by driving 0, and the silicon wafer is cleaned in the cleaning tank 101. And
Ammonia water and hydrogen peroxide water are automatically replenished to cleaning tank 101 by a fixed amount at fixed time intervals.
【０００４】しかし、この方法では洗浄槽１０１内の各
薬液ごとの濃度が一定になるように制御することが困難
であり、自動補充の方法が最適化されていない場合に
は、各薬液ごとの濃度の経時変化が激しくなり、濃度の
ばらつきが大きくなってしまう。However, in this method, it is difficult to control the concentration of each chemical in the cleaning tank 101 to be constant, and if the method of automatic replenishment is not optimized, it is difficult to control the concentration of each chemical. The concentration changes with time intensely, and the variation in the concentration increases.
【０００５】そこで、洗浄槽内の洗浄液の濃度を一定に
保つために、特開平４−２７８５２９号公報には、図７
に示すように、洗浄槽１５１に、アンモニアの濃度を計
測するアンモニア成分分析計１６１および過酸化水素の
濃度を計測する過酸化水素成分分析計１６２を取り付
け、洗浄液中のアンモニアおよび過酸化水素の濃度をそ
れぞれフィルタ１５４、ポンプ１５３および開閉弁１６
３を介して個別にモニタできるようにした洗浄装置が開
示されている。そして、各成分分析計１６１，１６２か
らの信号に基づいて、アンモニア補充槽１５５および過
酸化水素補充槽１５６にそれぞれ設けられた補充用開閉
弁１５５ａ，１５６ａを制御することで、濃度の減少し
た薬液を自動補充し、洗浄液の濃度を一定に保ってい
る。To keep the concentration of the cleaning liquid in the cleaning tank constant, Japanese Patent Application Laid-Open No. 4-278529 discloses FIG.
As shown in the figure, an ammonia component analyzer 161 for measuring the concentration of ammonia and a hydrogen peroxide component analyzer 162 for measuring the concentration of hydrogen peroxide are attached to the cleaning tank 151, and the concentrations of ammonia and hydrogen peroxide in the cleaning solution are measured. With the filter 154, the pump 153 and the on-off valve 16 respectively.
A cleaning device is disclosed, which can be monitored individually via the device 3. Then, based on signals from the component analyzers 161 and 162, the replenishment on-off valves 155a and 156a provided in the ammonia replenishment tank 155 and the hydrogen peroxide replenishment tank 156, respectively, are controlled. And the concentration of the washing solution is kept constant.
【０００６】また、アンモニアの蒸発等による濃度低下
に比べ、過酸化水素の濃度低下は一般的に小さいため、
特開平５−２５９１４１号公報には、過酸化水素水は補
充せず、アンモニア水のみを処理温度に応じて補充する
方法が開示されている。In addition, since the decrease in the concentration of hydrogen peroxide is generally smaller than the decrease in the concentration due to evaporation of ammonia, etc.,
JP-A-5-259141 discloses a method of replenishing only aqueous ammonia without replenishing aqueous hydrogen peroxide in accordance with the processing temperature.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、特開平
４−２７８５２９号公報に開示されたものでは、各薬液
の濃度が一定に保たれるように各薬液を補充するため、
洗浄槽に補充される薬液が大量に必要となる。また、自
動補充の方法が最適化されていない場合には、洗浄液の
洗浄特性を一定に保つことが困難になり、エッチングレ
ートや洗浄特性にばらつきが生じるといった問題があ
る。However, in the method disclosed in Japanese Patent Application Laid-Open No. 4-278529, each chemical solution is replenished so that the concentration of each chemical solution is kept constant.
A large amount of chemical solution to be replenished to the cleaning tank is required. If the automatic replenishment method is not optimized, it is difficult to keep the cleaning characteristics of the cleaning liquid constant, and there is a problem that the etching rate and the cleaning characteristics vary.
【０００８】また、特開平５−２５９１４１号公報に開
示されたものでは、アンモニア水のみを補充しているた
め過酸化水素水の使用量は削減されるものの、水の蒸発
等によって洗浄槽内の液面が低下した場合、アンモニア
水を補充して液面を上昇させると、アンモニア濃度が増
加し過酸化水素濃度が低下することになるため、アンモ
ニア濃度、過酸化水素濃度を一定に制御することが困難
になる。また、洗浄槽内の過酸化水素濃度が低下した場
合には、過酸化水素濃度を上昇させることができない。Further, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 5-259141, although the amount of hydrogen peroxide used is reduced because only ammonia water is replenished, the amount of water in the cleaning tank is reduced by evaporation of water. If the liquid level drops, replenishing the ammonia water and raising the liquid level will increase the ammonia concentration and decrease the hydrogen peroxide concentration.Therefore, keep the ammonia concentration and the hydrogen peroxide concentration constant. Becomes difficult. Further, when the concentration of hydrogen peroxide in the cleaning tank decreases, the concentration of hydrogen peroxide cannot be increased.
【０００９】そこで本発明は、過酸化水素の使用量を抑
えつつ薬液の濃度の最適化を図る洗浄用薬液の濃度管理
方法を提供することを目的とする。また本発明は、薬液
の濃度の最適化を図ることによって、安定した洗浄特性
でシリコンウェハの洗浄を行えるシリコンウェハ洗浄装
置を提供することを第２の目的とする。Accordingly, an object of the present invention is to provide a method for controlling the concentration of a cleaning chemical solution that optimizes the concentration of the chemical solution while suppressing the amount of hydrogen peroxide used. It is a second object of the present invention to provide a silicon wafer cleaning apparatus capable of cleaning a silicon wafer with stable cleaning characteristics by optimizing the concentration of a chemical solution.
【００１０】[0010]
【課題を解決するための手段】アンモニアと過酸化水素
との混合水溶液の洗浄特性は、アンモニア濃度と過酸化
水素濃度との比に依存することが知られており［応用物
理、第５９巻、第１１号、７９〜８０頁（１９９０
年）］、本発明はその点に着目したものである。It is known that the cleaning characteristics of the mixed aqueous solution of ammonia and hydrogen peroxide depend on the ratio between the concentration of ammonia and the concentration of hydrogen peroxide [Applied Physics, Vol. No. 11, pp. 79-80 (1990
The present invention focuses on this point.
【００１１】すなわち本発明の洗浄用薬液の濃度管理方
法は、アンモニアと過酸化水素の混合水溶液である洗浄
用薬液の濃度管理方法であって、 一定の時間間隔で前記洗浄用薬液のアンモニア濃度およ
び過酸化水素濃度の測定を行い、 前記測定の度ごとに前記洗浄用薬液に一定量のアンモニ
アを補充し、 前記測定の結果、アンモニア濃度に対する過酸化水素濃
度の比が前記洗浄用薬液の当初のアンモニア濃度に対す
る過酸化水素濃度の比以下である場合には、前記洗浄用
薬液に一定量の過酸化水素を補充するものである。That is, the method of controlling the concentration of a cleaning chemical solution of the present invention is a method of controlling the concentration of a cleaning chemical solution which is a mixed aqueous solution of ammonia and hydrogen peroxide. The hydrogen peroxide concentration is measured, and a constant amount of ammonia is replenished to the cleaning chemical solution each time the measurement is performed. As a result of the measurement, the ratio of the hydrogen peroxide concentration to the ammonia concentration is the initial value of the cleaning chemical solution. When the ratio is not more than the ratio of the concentration of hydrogen peroxide to the concentration of ammonia, a certain amount of hydrogen peroxide is added to the cleaning chemical solution.
【００１２】また、本発明のシリコンウェハ洗浄装置
は、アンモニアと過酸化水素の混合水溶液であるシリコ
ンウェハの洗浄用薬液を収容する洗浄槽と、 前記洗浄槽に補充されるアンモニア水を貯えるアンモニ
ア秤量槽と、 前記洗浄槽に補充される過酸化水素水を貯える過酸化水
素秤量槽と、 前記洗浄槽内の洗浄用薬液のアンモニア濃度および過酸
化水素濃度を一定の時間間隔で測定する濃度測定手段
と、 前記濃度測定手段による濃度の測定結果に基づき、前記
アンモニア秤量槽から前記洗浄槽に一定量のアンモニア
水を補充させ、かつ、アンモニア濃度に対する過酸化水
素濃度の比が前記洗浄用薬液の当初のアンモニア濃度に
対する過酸化水素濃度の比以下である場合に、前記過酸
化水素秤量槽から前記洗浄槽に一定量の過酸化水素水を
補充させる制御手段とを有する。Further, the present invention provides a silicon wafer cleaning apparatus, comprising: a cleaning tank for storing a cleaning liquid for silicon wafers, which is a mixed aqueous solution of ammonia and hydrogen peroxide; and an ammonia weighing tank for storing ammonia water to be replenished in the cleaning tank. A tank, a hydrogen peroxide weighing tank for storing a hydrogen peroxide solution to be replenished in the cleaning tank, and a concentration measuring means for measuring the ammonia concentration and the hydrogen peroxide concentration of the cleaning chemical in the cleaning tank at regular time intervals. And, based on the measurement result of the concentration by the concentration measuring means, to replenish a fixed amount of ammonia water from the ammonia weighing tank to the washing tank, and the ratio of the concentration of hydrogen peroxide to the ammonia concentration is the initial of the cleaning chemical solution When the ratio is less than the ratio of the concentration of hydrogen peroxide to the concentration of ammonia, a certain amount of aqueous hydrogen peroxide is supplied from the hydrogen peroxide weighing tank to the washing tank. Control means for replenishment.
【００１３】このように、測定されたアンモニア濃度に
対する過酸化水素濃度の比が洗浄用薬液の当初のアンモ
ニア濃度に対する過酸化水素濃度の比以下である場合
に、洗浄用薬液に一定量の過酸化水素を補充すること
で、洗浄用薬液中のアンモニアと過酸化水素の濃度比が
ほぼ一定に保たれ、安定した洗浄特性が維持される。一
方、アンモニア濃度が低下する傾向は過酸化水素濃度が
低下する傾向よりも大きく、濃度の測定の度ごとにアン
モニアを補充しても、アンモニア濃度が次第に低下する
場合もある。このような場合でも上述のように過酸化水
素を補充することで、従来のように過酸化水素濃度自体
を一定に保つように過酸化水素を補充するのに比べ、過
酸化水素の使用量は少なくなる。As described above, when the measured ratio of the concentration of hydrogen peroxide to the concentration of ammonia is equal to or less than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical, a certain amount of peroxide is added to the cleaning chemical. By replenishing hydrogen, the concentration ratio of ammonia and hydrogen peroxide in the cleaning chemical is kept almost constant, and stable cleaning characteristics are maintained. On the other hand, the tendency of the ammonia concentration to decrease is greater than the tendency of the hydrogen peroxide concentration to decrease, and even if ammonia is replenished each time the concentration is measured, the ammonia concentration may gradually decrease. Even in such a case, by replenishing hydrogen peroxide as described above, the amount of hydrogen peroxide used is smaller than in the conventional case where hydrogen peroxide is replenished to keep the hydrogen peroxide concentration itself constant. Less.
【００１４】[0014]
【発明の実施の形態】次に、本発明の実施形態について
図面を参照して説明する。Next, embodiments of the present invention will be described with reference to the drawings.
【００１５】図１は、本発明のシリコンウェハ洗浄装置
の一実施形態の構成図である。図１において、洗浄槽１
には、アンモニアと過酸化水素との混合水溶液である洗
浄液が満たされており、この中にシリコンウェハ（不図
示）が浸けられ、これによってシリコンウェハの洗浄が
行われる。シリコンウェハの洗浄処理中、洗浄槽１内の
洗浄液の温度は６０℃程度に保たれている。洗浄槽１は
オーバーフロー式の槽であり、オーバーフローした洗浄
液は、循環ポンプ３およびフィルタ４が設けられた循環
経路を通りフィルタで異物が除去されつつ循環される。FIG. 1 is a configuration diagram of an embodiment of a silicon wafer cleaning apparatus according to the present invention. In FIG. 1, a cleaning tank 1
Is filled with a cleaning solution that is a mixed aqueous solution of ammonia and hydrogen peroxide, in which a silicon wafer (not shown) is immersed, thereby cleaning the silicon wafer. During the cleaning process of the silicon wafer, the temperature of the cleaning liquid in the cleaning tank 1 is maintained at about 60 ° C. The cleaning tank 1 is an overflow type tank, and the overflowing cleaning liquid is circulated through a circulation path provided with the circulation pump 3 and the filter 4 while removing foreign matter by the filter.
【００１６】洗浄槽１中の洗浄液は、洗浄処理に伴い、
各成分の蒸発や分解等によりアンモニア濃度および過酸
化水素濃度が変化する。そこで、アンモニア水を貯える
アンモニア秤量槽５、過酸化水素水を貯える過酸化水素
秤量槽６および純水を貯える純水秤量槽７を設け、必要
に応じて洗浄槽１にアンモニア、過酸化水素または純水
を補充できるようになっている。The cleaning liquid in the cleaning tank 1 is subjected to the cleaning process,
The ammonia concentration and the hydrogen peroxide concentration change due to evaporation and decomposition of each component. Therefore, an ammonia weighing tank 5 for storing ammonia water, a hydrogen peroxide weighing tank 6 for storing hydrogen peroxide water, and a pure water weighing tank 7 for storing pure water are provided, and ammonia, hydrogen peroxide or Pure water can be replenished.
【００１７】アンモニア秤量槽５から洗浄槽１にアンモ
ニア水を補充する経路中にはアンモニア補充用ポンプ８
が設けられており、アンモニア補充用ポンプ８を駆動さ
せることで、アンモニア秤量槽５から洗浄槽１にアンモ
ニア水が補充される。同様に、過酸化水素秤量槽６から
洗浄槽１へ過酸化水素水を補充する経路中には過酸化水
素補充用ポンプ９が設けられ、純水秤量槽７から洗浄槽
１へ純水を補充する経路中には純水補充用ポンプ１０が
設けられている。In the path for replenishing the ammonia water from the ammonia weighing tank 5 to the cleaning tank 1, an ammonia replenishing pump 8 is provided.
By driving the ammonia replenishing pump 8, the ammonia water is replenished from the ammonia weighing tank 5 to the cleaning tank 1. Similarly, a hydrogen peroxide replenishing pump 9 is provided in a path for replenishing the hydrogen peroxide solution from the hydrogen peroxide weighing tank 6 to the cleaning tank 1, and replenishes pure water from the pure water weighing tank 7 to the cleaning tank 1. A pure water replenishing pump 10 is provided in the path.
【００１８】一方、洗浄槽１の循環経路中には、循環経
路を通過する洗浄水のアンモニア濃度および過酸化水素
濃度を測定する組成モニタ２が設けられている。組成モ
ニタ２は一定時間間隔で各成分の濃度を測定し、その測
定結果は第一判断手段１１に送られる。On the other hand, in the circulation path of the cleaning tank 1, a composition monitor 2 for measuring the ammonia concentration and the hydrogen peroxide concentration of the cleaning water passing through the circulation path is provided. The composition monitor 2 measures the concentration of each component at regular time intervals, and the measurement result is sent to the first determination means 11.
【００１９】第一判断手段１１には、アンモニア濃度お
よび過酸化水素濃度の下限値が設定されており、第一判
断手段１１は、これら下限値および組成モニタ２での測
定結果に基づいて、アンモニア水を補充するか否かを判
断する。アンモニア水を補充すると判断した場合には、
アンモニア補充用ポンプ８に駆動信号を送り、一定量の
アンモニア水を洗浄槽１に補充させる。また、第一判断
手段１１は、組成モニタ２での測定結果を第二判断手段
１２へ送る。The first judgment means 11 sets the lower limit of the ammonia concentration and the concentration of hydrogen peroxide. The first judgment means 11 sets the lower limit of the ammonia concentration and the hydrogen peroxide concentration on the basis of the measurement result of the composition monitor 2. Judge whether to add water. If you decide to replenish ammonia water,
A driving signal is sent to the ammonia replenishing pump 8 to replenish the cleaning tank 1 with a certain amount of aqueous ammonia. The first judging means 11 sends the measurement result of the composition monitor 2 to the second judging means 12.
【００２０】第二判断手段１２は、組成モニタ２での測
定結果および過去の補充履歴に基づいて、過酸化水素水
を補充するか純水を補充するかを判断するものである。
過酸化水素水を補充すると判断した場合には、過酸化水
素補充用ポンプ９に駆動信号を送り、一定量の過酸化水
素水を洗浄槽１に補充させる。また、純水を補充すると
判断した場合には、純水補充用ポンプ１０に駆動信号を
送り、一定量の純水を洗浄槽１に補充させる。これら第
一判断手段１１と第二判断手段１２とで、組成モニタ２
での濃度測定の結果に基づいて洗浄槽１にアンモニア
水、過酸化水素水あるいは純水を補充させる制御手段が
構成される。The second judging means 12 judges whether to replenish the hydrogen peroxide solution or pure water based on the measurement result of the composition monitor 2 and the past replenishment history.
When it is determined that the hydrogen peroxide solution is to be replenished, a drive signal is sent to the hydrogen peroxide replenishing pump 9 to replenish the cleaning tank 1 with a certain amount of the hydrogen peroxide solution. When it is determined that pure water is to be replenished, a drive signal is sent to the pure water replenishing pump 10 to replenish the cleaning tank 1 with a certain amount of pure water. The first monitor 11 and the second monitor 12 use the composition monitor 2
Control means for replenishing the cleaning tank 1 with ammonia water, hydrogen peroxide water or pure water based on the result of the concentration measurement in the step (a).
【００２１】次に、上述したシリコンウェハ洗浄装置に
よる洗浄処理中の、アンモニア水、過酸化水素水および
純水の補充手順について、図２のフローチャートを参照
しつつ説明する。Next, a procedure for replenishing aqueous ammonia, aqueous hydrogen peroxide and pure water during the cleaning process by the above-described silicon wafer cleaning apparatus will be described with reference to the flowchart of FIG.
【００２２】洗浄処理に先立ち、第一判断手段１１にア
ンモニア濃度および過酸化水素濃度の下限値を設定して
おく。この下限値は、シリコンウェハの洗浄が行えなく
なるアンモニアおよび過酸化水素の濃度である。また、
洗浄槽１には、予め決められた濃度でアンモニアおよび
過酸化水素が混合された水溶液が満たされている。Prior to the cleaning process, the lower limit values of the ammonia concentration and the hydrogen peroxide concentration are set in the first judging means 11. The lower limit is the concentration of ammonia and hydrogen peroxide at which the silicon wafer cannot be cleaned. Also,
The cleaning tank 1 is filled with an aqueous solution in which ammonia and hydrogen peroxide are mixed at a predetermined concentration.
【００２３】シリコンウェハの洗浄処理中は、洗浄槽１
内の洗浄液は循環経路を介して循環され、組成モニタ２
によって、洗浄液中のアンモニア濃度および過酸化水素
濃度が一定時間間隔で測定される。この測定結果は第一
判断手段１１に送られ、その回数がカウント手段（不図
示）で測定回数としてカウントされる（ステップＳ
１）。During the cleaning process of the silicon wafer, the cleaning tank 1 is used.
The cleaning liquid in the inside is circulated through the circulation path, and the composition monitor 2
Thus, the ammonia concentration and the hydrogen peroxide concentration in the cleaning solution are measured at regular time intervals. This measurement result is sent to the first judging means 11, and the number of times is counted as the number of times of measurement by the counting means (not shown) (Step S).
1).
【００２４】第一判断手段１１では、測定回数が３回目
以上であるか否かを判断する（ステップＳ２）。測定回
数が１回目および２回目の場合には、アンモニア補充用
ポンプ８および過酸化水素補充用ポンプ９を駆動し、ア
ンモニア水および過酸化水素水をそれぞれ一定量だけ洗
浄槽１に補充する（ステップＳ３）。ここで、アンモニ
ア水および過酸化水素水の補充量はそれぞれ、測定時間
間隔での減少量に基づき、アンモニアおよび過酸化水素
の濃度変動が大きくならない範囲で予め設定された量で
ある。なお、以下の工程でアンモニア水や過酸化水素水
を補充する場合も、それぞれの１回の補充量は、ここで
補充する量と同じ量である。The first judging means 11 judges whether or not the number of measurements is the third or more (Step S2). When the number of measurements is the first and second times, the ammonia replenishing pump 8 and the hydrogen peroxide replenishing pump 9 are driven to replenish the cleaning tank 1 with the ammonia water and the hydrogen peroxide water by a fixed amount (step). S3). Here, the replenishment amounts of the ammonia water and the hydrogen peroxide solution are predetermined amounts based on the decrease amounts at the measurement time intervals within a range in which the concentration fluctuations of the ammonia and the hydrogen peroxide do not increase. In addition, also in the case of replenishing ammonia water or hydrogen peroxide water in the following steps, the replenishment amount for each one time is the same as the amount replenished here.
【００２５】測定回数が３回目以降の場合には、第一判
断手段１１は、アンモニア濃度が下限値より大きいか否
かを判断し（ステップＳ４）、さらに、過酸化水素濃度
が下限値よりも大きいか否かを判断する（ステップＳ
５）。アンモニア濃度または過酸化水素濃度のいずれか
が下限値以下であれば、アラームを発し（ステップＳ
６）、洗浄槽１内の洗浄液を交換する必要があることを
知らせる。アラームが発せられたら洗浄処理を中断し、
洗浄槽１内の洗浄液を新たなものと交換する。If the number of measurements is the third or later, the first judging means 11 judges whether or not the ammonia concentration is higher than the lower limit (step S4). It is determined whether or not it is larger (step S
5). If either the ammonia concentration or the hydrogen peroxide concentration is below the lower limit, an alarm is issued (step S
6) Informing that the cleaning liquid in the cleaning tank 1 needs to be replaced. When an alarm is issued, the cleaning process is interrupted,
The cleaning liquid in the cleaning tank 1 is exchanged for a new one.
【００２６】一方、アンモニア濃度および過酸化水素濃
度がいずれも下限値よりも大きいときには、アンモニア
補充用ポンプ８を駆動し、洗浄槽１にアンモニア水を補
充する（ステップＳ７）。On the other hand, when both the ammonia concentration and the hydrogen peroxide concentration are larger than the lower limit values, the ammonia replenishing pump 8 is driven to replenish the cleaning tank 1 with ammonia water (step S7).
【００２７】それと同時に、アンモニア濃度および過酸
化水素濃度の測定結果は第二判断手段１２に送られる。
第二判断手段１２では、まず、洗浄液の当初のアンモニ
ア濃度に対する過酸化水素濃度の比と一致するような、
測定されたアンモニア濃度に対する過酸化水素濃度であ
る基準値を算出する（ステップＳ８）。基準値は、例え
ば図３に示すような、濃度比を一定とした場合のアンモ
ニア濃度に対する過酸化水素濃度の検量線データを記憶
手段に記憶させておき、この検量線データに基づいて算
出することができる。At the same time, the measurement results of the ammonia concentration and the hydrogen peroxide concentration are sent to the second judging means 12.
In the second judging means 12, first, such as to match the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning liquid,
A reference value that is the concentration of hydrogen peroxide with respect to the measured ammonia concentration is calculated (step S8). As the reference value, for example, calibration curve data of the concentration of hydrogen peroxide with respect to the concentration of ammonia when the concentration ratio is constant as shown in FIG. 3 is stored in the storage means, and is calculated based on the calibration curve data. Can be.
【００２８】基準値が算出されたら、組成モニタ２で測
定された過酸化水素濃度が基準値よりも大きいか否かを
判断し（ステップＳ９）、基準値よりも大きい場合に
は、純水補充用ポンプ１０を駆動して洗浄槽１に一定量
の純水を補充する（ステップＳ１４）。After the reference value has been calculated, it is determined whether or not the concentration of hydrogen peroxide measured by the composition monitor 2 is higher than the reference value (step S9). The cleaning pump 1 is driven to replenish the cleaning tank 1 with a certain amount of pure water (step S14).
【００２９】また、第二判断手段１２には、前回および
前々回の補充履歴（純水を補充したか否か）および過酸
化水素濃度が記憶されており、今回測定された過酸化水
素濃度が基準値以下である場合には、前回の測定時に純
水を補充したか否かを判断し（ステップＳ１０）、純水
を補充していた場合には一定量の過酸化水素水を補充す
る（ステップＳ１５）。純水を補充していなかった場合
には、さらに、今回測定された過酸化水素濃度が前回の
測定結果よりも上昇しているか否かを判断し（ステップ
Ｓ１１）、上昇していれば、一定量の過酸化水素水を補
充する（ステップＳ１５）。The second judging means 12 stores the replenishment histories (whether or not pure water was replenished) and the hydrogen peroxide concentration of the previous and two previous times, and the hydrogen peroxide concentration measured this time is used as a reference. If the value is equal to or less than the value, it is determined whether or not pure water was replenished during the previous measurement (step S10). If pure water was replenished, a fixed amount of hydrogen peroxide solution is replenished (step S10). S15). If pure water has not been replenished, it is further determined whether or not the hydrogen peroxide concentration measured this time is higher than the previous measurement result (step S11). The amount of hydrogen peroxide solution is replenished (step S15).
【００３０】過酸化水素水濃度が前回の測定結果よりも
上昇していなければ、前々回の測定時に純水を補充した
か否かを判断し（ステップＳ１２）、純水を補充してい
た場合には一定量の過酸化水素水を補充する（ステップ
Ｓ１５）。前々回に純水を補充していなかった場合に
は、さらに、今回測定された過酸化水素水濃度が前々回
の測定結果よりも上昇しているか否かを判断し（ステッ
プＳ１３）、上昇していれば、一定量の過酸化水素水を
補充する（ステップＳ１５）。そして、上昇していなけ
れば、アラームを発し（ステップＳ１６）、洗浄槽１の
洗浄液を交換する必要があることを知らせる。アラーム
が発せられたら洗浄処理を中断し、洗浄槽１内の洗浄液
を新たなものと交換する。If the concentration of the hydrogen peroxide solution has not increased from the previous measurement result, it is determined whether or not pure water has been replenished at the time of the previous measurement (step S12). Replenishes a fixed amount of aqueous hydrogen peroxide (step S15). If the pure water has not been replenished two times before, it is further determined whether or not the hydrogen peroxide solution concentration measured this time is higher than the measurement result obtained two times before (step S13). For example, a fixed amount of aqueous hydrogen peroxide is replenished (step S15). If it has not risen, an alarm is issued (step S16) to inform that the cleaning liquid in the cleaning tank 1 needs to be replaced. When an alarm is issued, the cleaning process is interrupted, and the cleaning liquid in the cleaning tank 1 is replaced with a new one.
【００３１】以上述べたように、本実施形態では、アン
モニア濃度および過酸化水素濃度が下限値以下でない限
りは、アンモニア水は濃度測定ごとに補充される。ま
た、過酸化水素濃度が基準値以下のときには、前回およ
び前々回に過酸化水素水を補充し、しかも、過酸化水素
濃度が過去の２回に比べて上昇していない場合にアラー
ムが発せられ、それ以外の場合には過酸化水素水が補充
され、これら一連の手順が繰り返される。As described above, in this embodiment, as long as the ammonia concentration and the hydrogen peroxide concentration are not lower than the lower limits, the ammonia water is replenished every time the concentration is measured. When the hydrogen peroxide concentration is lower than the reference value, an alarm is issued when the hydrogen peroxide solution is replenished last time and two times before and when the hydrogen peroxide concentration has not increased compared to the past two times. In other cases, the hydrogen peroxide solution is replenished, and these series of procedures are repeated.
【００３２】ここで、上述した手順について、数値を挙
げて具体的に説明する。Here, the above-described procedure will be specifically described with numerical values.
【００３３】初期条件として、洗浄液の当初のアンモニ
ア濃度は１％、過酸化水素濃度は５％とする。また、ア
ンモニア濃度の下限値を０．７５％、過酸化水素濃度の
下限値を３．５％に設定し、１回の補充でのアンモニア
水の補充量を１００ｍｌ、過酸化水素水の補充量を２０
ｍｌ、純水の補充量を２０ｍｌとする。As initial conditions, the initial concentration of ammonia in the cleaning liquid is 1%, and the concentration of hydrogen peroxide is 5%. Also, the lower limit of the ammonia concentration was set to 0.75%, the lower limit of the hydrogen peroxide concentration was set to 3.5%, the replenishment amount of ammonia water in one replenishment was 100 ml, and the replenishment amount of hydrogen peroxide water was set. 20
ml, and the replenishment amount of pure water is 20 ml.
【００３４】いま、アンモニア濃度および過酸化水素濃
度のｎ回目（ｎ＞３）の測定を行ったところ、アンモニ
ア濃度が０．８％、過酸化水素濃度が３．８％であった
とする。測定結果は、第一判断手段１１へ送られる。こ
れらの濃度はいずれも下限値よりも大きいので、アンモ
ニア水が１００ｍｌ補充される。次いで、第二判断手段
１２で基準値が算出される。当初のアンモニア濃度が１
％、過酸化水素濃度が５％であり、アンモニア濃度に対
する過酸化水素濃度の比は５となる。したがって、測定
されたアンモニア濃度は０．８％に対し、比が５となる
過酸化水素濃度、すなわち基準値は４％となる。Now, it is assumed that the ammonia concentration and the hydrogen peroxide concentration are 0.8% and the hydrogen peroxide concentration is 3.8% when the n-th measurement (n> 3) is performed. The measurement result is sent to the first determination means 11. Since these concentrations are all higher than the lower limit, 100 ml of ammonia water is replenished. Next, a reference value is calculated by the second determining means 12. Initial ammonia concentration is 1
%, The hydrogen peroxide concentration is 5%, and the ratio of the hydrogen peroxide concentration to the ammonia concentration is 5. Therefore, the measured ammonia concentration is 0.8%, whereas the hydrogen peroxide concentration at which the ratio is 5 is obtained, that is, the reference value is 4%.
【００３５】ここで、第二判断手段１２には、前回の補
充が純水であったことが記憶されているとする。今回測
定された過酸化水素濃度は基準値以下であり、しかも前
回の補充が純水であったので、ここでは過酸化水素水が
２０ｍｌ補充される。Here, it is assumed that the second judgment means 12 stores that the previous replenishment was pure water. The hydrogen peroxide concentration measured this time is below the reference value, and since the previous replenishment was pure water, 20 ml of hydrogen peroxide solution is replenished here.
【００３６】過酸化水素水の補充後、約５分の間隔をお
いて、洗浄液のアンモニア濃度および過酸化水素濃度を
測定する。その結果、アンモニア濃度が０．８％、過酸
化水素濃度が４％という結果が得られたとする。アンモ
ニアは蒸発等のため濃度が低下する傾向が大きいため、
アンモニア水を補充しても濃度が上昇しない場合もあ
る。After the replenishment of the hydrogen peroxide solution, the ammonia concentration and the hydrogen peroxide concentration of the cleaning solution are measured at intervals of about 5 minutes. As a result, it is assumed that the result that the ammonia concentration is 0.8% and the hydrogen peroxide concentration is 4% is obtained. Since the concentration of ammonia tends to decrease due to evaporation, etc.,
In some cases, the concentration does not increase even if ammonia water is replenished.
【００３７】測定結果は再び第一判断手段１１へ送ら
れ、第一判断手段１１でそれぞれ下限値と比較される。
ここでも、それぞれの濃度は下限値よりも大きいので、
アンモニア水が１００ｍｌ補充される。一方、第二判断
手段１２では、アンモニア濃度０．８％に対する過酸化
水素濃度の基準値４％が算出される。ここでは、過酸化
水素濃度は基準値以下であるので、純水が２０ｍｌ補充
される。The measurement result is sent to the first judging means 11 again, where it is compared with the lower limit value.
Again, each concentration is greater than the lower limit,
100 ml of aqueous ammonia is replenished. On the other hand, the second determination means 12 calculates a reference value of 4% of the hydrogen peroxide concentration with respect to the ammonia concentration of 0.8%. Here, since the hydrogen peroxide concentration is lower than the reference value, 20 ml of pure water is replenished.
【００３８】上述した一連の補充手順が、シリコンウェ
ハの洗浄処理の終了、あるいは洗浄液の交換まで繰り返
される。The above-described series of replenishment procedures are repeated until the silicon wafer cleaning process is completed or the cleaning liquid is replaced.
【００３９】以上説明した手順にしたがってアンモニア
水、過酸化水素水および純水を補充することによって、
例えば、過酸化水素濃度に着目すると、図４に示すよう
に、濃度自体は時間の経過とともに減少してくる。しか
し、アンモニア濃度との比で見ると、図５に示すよう
に、ほぼ一定に保たれる。その結果、洗浄液の洗浄特性
がほぼ一定に保たれ、常に安定した洗浄特性でシリコン
ウェハを洗浄することができる。さらに、測定された過
酸化水素濃度と算出された基準値とを比較し、必要に応
じて純水を補充することで、アンモニア濃度の低下が著
しくアンモニア濃度に対する過酸化水素濃度の比が上昇
する傾向にあるような場合であっても、アンモニア濃度
に対する過酸化水素濃度の比をより効果的に安定化させ
ることができる。By replenishing ammonia water, hydrogen peroxide water and pure water according to the procedure described above,
For example, focusing on the concentration of hydrogen peroxide, as shown in FIG. 4, the concentration itself decreases over time. However, when viewed from the ratio with respect to the ammonia concentration, as shown in FIG. 5, it is kept almost constant. As a result, the cleaning characteristics of the cleaning liquid are kept substantially constant, and the silicon wafer can be always cleaned with stable cleaning characteristics. Further, by comparing the measured hydrogen peroxide concentration with the calculated reference value, and by adding pure water as necessary, the decrease in the ammonia concentration is remarkable, and the ratio of the hydrogen peroxide concentration to the ammonia concentration increases. Even in such a case, the ratio of the concentration of hydrogen peroxide to the concentration of ammonia can be more effectively stabilized.
【００４０】また、アンモニアおよび過酸化水素の使用
量（補充量）に着目すると、アンモニアについては、一
定の時間間隔で一定量ずつ補充することになるので、従
来と使用量は変わらない。一方、過酸化水素は、その濃
度のアンモニア濃度との比が一定になるように補充され
るが、アンモニア濃度は、洗浄水の加熱による蒸発など
のため減少する傾向が大きいため一定の時間間隔で補充
しても実際には経時的に減少している。したがって、ア
ンモニア濃度が減少するにつれ、過酸化水素の補充量
（正確には補充回数）も少なくなり、結果的に、従来の
ように過酸化水素濃度自体を一定に保つように過酸化水
素を補充する場合に比べて過酸化水素の使用量は少なく
なる。逆にいえば、従来は、アンモニア濃度に対する過
酸化水素濃度の比が時間の経過とともに高くなり、洗浄
特性から見れば必要以上に過酸化水素を補充していたこ
とになる。Focusing on the used amount (replenishment amount) of ammonia and hydrogen peroxide, ammonia is replenished by a fixed amount at a fixed time interval, so that the used amount is not different from the conventional amount. On the other hand, hydrogen peroxide is replenished so that the ratio of the concentration to the ammonia concentration becomes constant. However, the ammonia concentration tends to decrease due to evaporation due to heating of the washing water and the like. Even if it is replenished, it actually decreases over time. Therefore, as the ammonia concentration decreases, the amount of hydrogen peroxide replenishment (more precisely, the number of replenishments) also decreases, and as a result, hydrogen peroxide is replenished so as to keep the hydrogen peroxide concentration itself constant as in the conventional case. In this case, the amount of hydrogen peroxide used is smaller than in the case where the above is performed. In other words, conventionally, the ratio of the concentration of hydrogen peroxide to the concentration of ammonia increases with the passage of time, which means that hydrogen peroxide has been replenished more than necessary from the viewpoint of cleaning characteristics.
【００４１】なお、過酸化水素濃度は次第に低下してい
き、最終的に下限値以下になった場合には洗浄液を交換
する必要が生じるため、従来と比較して洗浄液の交換頻
度が高くなることが懸念される。しかし、過酸化水素濃
度の低下はアンモニア濃度の低下に対応しており、従来
においてもアンモニア濃度は次第に低下し、下限値以下
になった場合に洗浄液を交換している。したがって、本
発明によっても洗浄液の交換頻度が高くなることはな
い。Since the concentration of hydrogen peroxide gradually decreases and eventually becomes lower than the lower limit, it is necessary to replace the cleaning solution. Is concerned. However, a decrease in the concentration of hydrogen peroxide corresponds to a decrease in the concentration of ammonia. Conventionally, the concentration of ammonia gradually decreases, and when the ammonia concentration falls below the lower limit, the cleaning liquid is replaced. Therefore, the frequency of replacement of the cleaning liquid does not increase according to the present invention.
【００４２】本実施形態では過去２回の測定結果および
補充履歴を考慮して過酸化水素を補充するかアラームを
発するかを判断しているが、必ずしもその必要はなく、
過酸化水素濃度が基準値以下であれば過酸化水素を補充
し、洗浄液の交換の必要性の判断はアンモニア濃度およ
び過酸化水素濃度の下限値に基づいて行うようにしても
よい。ただし、過去２回とも過酸化水素水を補充しても
その濃度が上昇しないことは、洗浄液の劣化が著しく、
洗浄能力が低下していることを示すものであるため、本
実施形態のように過去の補充履歴を考慮することは、洗
浄特性を安定させる上でより好ましい。In this embodiment, it is determined whether hydrogen peroxide is to be replenished or an alarm is issued in consideration of the past two measurement results and the replenishment history.
If the hydrogen peroxide concentration is equal to or less than the reference value, hydrogen peroxide may be replenished, and the necessity of replacing the cleaning solution may be determined based on the lower limit of the ammonia concentration and the hydrogen peroxide concentration. However, the fact that the concentration did not increase even if the hydrogen peroxide solution was replenished in the past two times indicates that the cleaning solution was significantly deteriorated,
Since this indicates that the cleaning ability has decreased, it is more preferable to consider the past replenishment history as in the present embodiment in order to stabilize the cleaning characteristics.
【００４３】本発明は、アンモニアと過酸化水素の混合
水溶液の濃度管理に対して著しく効果を示すものである
が、それに限らず、硫酸と過酸化水素水の混合水溶液
等、様々な薬液にも利用できる。The present invention is remarkably effective in controlling the concentration of a mixed aqueous solution of ammonia and hydrogen peroxide. However, the present invention is not limited to this, and is applicable to various chemical solutions such as a mixed aqueous solution of sulfuric acid and hydrogen peroxide. Available.
【００４４】[0044]
【発明の効果】以上説明したように、本発明の洗浄用薬
液の濃度管理方法は、アンモニア濃度に対する過酸化水
素濃度の比が当初のアンモニア濃度に対する過酸化水素
濃度の比以下である場合に一定量の過酸化水素を補充す
るので、アンモニアと過酸化水素の濃度比をほぼ一定に
保ち、安定した洗浄特性を維持しながらも、過酸化水素
の使用量を低減することができる。As described above, the method for controlling the concentration of a cleaning chemical solution according to the present invention is not limited to the case where the ratio of the concentration of hydrogen peroxide to the concentration of ammonia is equal to or less than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia. Since the amount of hydrogen peroxide is replenished, the concentration ratio of ammonia and hydrogen peroxide can be kept almost constant, and the amount of hydrogen peroxide used can be reduced while maintaining stable cleaning characteristics.
【００４５】また、アンモニア濃度に対する過酸化水素
濃度の比が当初のアンモニア濃度に対する過酸化濃度の
比よりも大きい場合には一定量の純水を補充すること
で、アンモニアと過酸化水素の濃度比をより安定させる
ことができる。特にこの場合、過去２回分の補充履歴お
よび過酸化水素濃度を考慮することで、洗浄用薬液の交
換時期を知ることができる。When the ratio of the concentration of hydrogen peroxide to the concentration of ammonia is larger than the ratio of the concentration of peroxide to the initial concentration of ammonia, a certain amount of pure water is replenished to obtain the concentration ratio of ammonia and hydrogen peroxide. Can be made more stable. In particular, in this case, by considering the past two replenishment histories and the concentration of hydrogen peroxide, it is possible to know the replacement time of the cleaning chemical.
【００４６】本発明のシリコンウェハ洗浄装置は、洗浄
槽へのアンモニアおよび過酸化水素の補充を制御する制
御手段を有し、この制御手段により上記本発明の洗浄用
薬液の濃度管理方法が実施されるので、安定した洗浄特
性で、しかも少ない過酸化水素の使用量でシリコンウェ
ハを洗浄することができる。また、アンモニア濃度ある
いは過酸化水素濃度のいずれか一方が、予め設定された
下限値以下である場合にアラームを発することで、洗浄
用薬液の交換時期を知ることができる。The silicon wafer cleaning apparatus of the present invention has control means for controlling the replenishment of ammonia and hydrogen peroxide into the cleaning tank, and the control means implements the above-described method for controlling the concentration of the cleaning chemical solution of the present invention. Therefore, the silicon wafer can be cleaned with stable cleaning characteristics and using a small amount of hydrogen peroxide. In addition, by issuing an alarm when either the ammonia concentration or the hydrogen peroxide concentration is equal to or lower than a preset lower limit value, it is possible to know the replacement timing of the cleaning chemical.
【図１】本発明のシリコンウェハ洗浄装置の一実施形態
の構成図である。FIG. 1 is a configuration diagram of an embodiment of a silicon wafer cleaning apparatus of the present invention.
【図２】図１に示したシリコンウェハ洗浄装置の洗浄液
濃度管理手順を示すフローチャートである。FIG. 2 is a flowchart showing a cleaning liquid concentration management procedure of the silicon wafer cleaning apparatus shown in FIG.
【図３】濃度比を一定とした場合のアンモニア濃度に対
する過酸化水素水濃度の検量線を示すグラフである。FIG. 3 is a graph showing a calibration curve of an aqueous hydrogen peroxide concentration with respect to an ammonia concentration when the concentration ratio is constant.
【図４】本発明の洗浄用薬液の濃度管理方法にしたがっ
てアンモニア水および過酸化水素水を補充した場合の、
過酸化水素濃度の経時的変化の一例を示すグラフであ
る。FIG. 4 shows a case where ammonia water and hydrogen peroxide solution are replenished according to the concentration control method for a cleaning chemical solution of the present invention.
5 is a graph showing an example of a change with time of the concentration of hydrogen peroxide.
【図５】本発明の洗浄用薬液の濃度管理方法にしたがっ
てアンモニア水および過酸化水素水を補充した場合の、
アンモニア濃度と過酸化水素濃度との比の、経時的変化
の一例を示すグラフである。FIG. 5 shows a case where ammonia water and hydrogen peroxide solution are replenished in accordance with the method for controlling the concentration of a cleaning chemical solution of the present invention.
It is a graph which shows an example of a time-dependent change of the ratio of the ammonia concentration and the hydrogen peroxide concentration.
【図６】従来のシリコンウェハ洗浄装置の一例の構成図
である。FIG. 6 is a configuration diagram of an example of a conventional silicon wafer cleaning apparatus.
【図７】従来のシリコンウェハ洗浄装置の他の例の構成
図である。FIG. 7 is a configuration diagram of another example of a conventional silicon wafer cleaning apparatus.
１ 洗浄槽 ２ 組成モニタ ３ フィルタ ４ 循環ポンプ ５ アンモニア秤量槽 ６ 過酸化水素秤量槽 ７ 純水秤量槽 ８ アンモニア補充用ポンプ ９ 過酸化水素補充用ポンプ １０ 純水補充用ポンプ １１ 第一判断手段 １２ 第二判断手段 DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Composition monitor 3 Filter 4 Circulation pump 5 Ammonia weighing tank 6 Hydrogen peroxide weighing tank 7 Pure water weighing tank 8 Ammonia replenishment pump 9 Hydrogen peroxide replenishment pump 10 Pure water replenishment pump 11 First judgment means 12 Second judgment means
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) H01L 21/304 ──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. 6 , DB name) H01L 21/304
Claims (7)
ある洗浄用薬液の濃度管理方法であって、 一定の時間間隔で前記洗浄用薬液のアンモニア濃度およ
び過酸化水素濃度の測定を行い、 前記測定の度ごとに前記洗浄用薬液に一定量のアンモニ
アを補充し、 前記測定の結果、アンモニア濃度に対する過酸化水素濃
度の比が前記洗浄用薬液の当初のアンモニア濃度に対す
る過酸化水素濃度の比以下である場合には、前記洗浄用
薬液に一定量の過酸化水素を補充する、洗浄用薬液の濃
度管理方法。1. A method for controlling the concentration of a cleaning chemical solution which is a mixed aqueous solution of ammonia and hydrogen peroxide, comprising: measuring the ammonia concentration and the hydrogen peroxide concentration of the cleaning chemical solution at regular time intervals; The cleaning chemical solution is replenished with a fixed amount of ammonia at every time.As a result of the measurement, the ratio of the hydrogen peroxide concentration to the ammonia concentration is equal to or less than the hydrogen peroxide concentration ratio to the initial ammonia concentration of the cleaning chemical solution. In some cases, a method for controlling the concentration of a cleaning chemical solution comprises replenishing the cleaning chemical solution with a fixed amount of hydrogen peroxide.
る過酸化水素濃度の比が前記洗浄用薬液の当初のアンモ
ニア濃度に対する過酸化水素濃度の比よりも大きい場合
には、前記洗浄用薬液に一定量の純水を補充する、請求
項１に記載の洗浄用薬液の濃度管理方法。2. As a result of the measurement, when the ratio of the concentration of hydrogen peroxide to the concentration of ammonia is larger than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical, a certain amount of the cleaning chemical is added to the cleaning chemical. The method according to claim 1, wherein pure water is supplied.
る過酸化水素濃度の比が前記洗浄用薬液の当初のアンモ
ニア濃度に対する過酸化水素濃度の比以下であるときに
は、前回もしくは前々回の測定時に純水を補充したか、
または、過酸化水素濃度が前回もしくは前々回の測定結
果に比べて上昇している場合にのみ過酸化水素水を補充
し、それ以外の場合には前記洗浄用薬液を新たなものと
交換する、請求項２に記載の洗浄用薬液の濃度管理方
法。3. As a result of the measurement, when the ratio of the concentration of hydrogen peroxide to the concentration of ammonia is equal to or less than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical solution, pure water is used at the previous or second-last measurement. Refilled,
Alternatively, replenish the hydrogen peroxide solution only when the hydrogen peroxide concentration is higher than the previous or two previous measurement results, otherwise replace the cleaning chemical with a new one. Item 3. A method for controlling the concentration of a cleaning chemical according to Item 2.
あるシリコンウェハの洗浄用薬液を収容する洗浄槽と、 前記洗浄槽に補充されるアンモニア水を貯えるアンモニ
ア秤量槽と、 前記洗浄槽に補充される過酸化水素水を貯える過酸化水
素秤量槽と、 前記洗浄槽内の洗浄用薬液のアンモニア濃度および過酸
化水素濃度を一定の時間間隔で測定する濃度測定手段
と、 前記濃度測定手段による濃度の測定結果に基づき、前記
アンモニア秤量槽から前記洗浄槽に一定量のアンモニア
水を補充させ、かつ、アンモニア濃度に対する過酸化水
素濃度の比が前記洗浄用薬液の当初のアンモニア濃度に
対する過酸化水素濃度の比以下である場合に、前記過酸
化水素秤量槽から前記洗浄槽に一定量の過酸化水素水を
補充させる制御手段とを有するシリコンウェハ洗浄装
置。4. A cleaning tank for accommodating a cleaning solution for silicon wafers, which is a mixed aqueous solution of ammonia and hydrogen peroxide, an ammonia weighing tank for storing ammonia water to be replenished in the cleaning tank, A hydrogen peroxide weighing tank for storing hydrogen peroxide solution, a concentration measuring means for measuring the ammonia concentration and the hydrogen peroxide concentration of the cleaning chemical in the cleaning tank at regular time intervals, and a concentration measuring means for measuring the concentration by the concentration measuring means. Based on the measurement results, a fixed amount of aqueous ammonia is replenished from the ammonia weighing tank to the cleaning tank, and the ratio of the concentration of hydrogen peroxide to the concentration of ammonia is the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical solution. Control means for replenishing a fixed amount of hydrogen peroxide solution from the hydrogen peroxide weighing tank to the cleaning tank when the ratio is not more than the ratio. Wafer cleaning equipment.
過酸化水素濃度の下限値がそれぞれ設定されており、前
記濃度測定手段で測定されたアンモニア濃度あるいは過
酸化水素濃度のいずれか一方が前記下限値以下である場
合には、前記洗浄槽内の洗浄用薬液の交換のためのアラ
ームを発する請求項５に記載のシリコンウェハ洗浄装
置。5. The control means has a lower limit of the ammonia concentration and the hydrogen peroxide concentration set therein, and one of the ammonia concentration and the hydrogen peroxide concentration measured by the concentration measuring means is the lower limit. 6. The silicon wafer cleaning apparatus according to claim 5, wherein an alarm for exchanging a cleaning chemical in the cleaning tank is issued in the following cases.
水秤量槽をさらに有し、 前記制御手段は、前記濃度測定手段による濃度の測定の
結果、アンモニア濃度に対する過酸化水素濃度の比が前
記洗浄用薬液の当初のアンモニア濃度に対する過酸化水
素濃度の比よりも大きい場合には、前記純水秤量槽から
前記洗浄槽に一定量の純水を補充させる請求項４または
５に記載のシリコンウェハ洗浄装置。6. The apparatus according to claim 6, further comprising a pure water weighing tank for storing pure water to be replenished in the washing tank, wherein the control unit determines a ratio of a concentration of hydrogen peroxide to a concentration of ammonia as a result of measuring the concentration by the concentration measuring unit. The method according to claim 4, wherein when the ratio is larger than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical, a certain amount of pure water is replenished from the pure water weighing tank to the cleaning tank. Silicon wafer cleaning equipment.
濃度測定時の補充履歴および過酸化水素濃度が記憶さ
れ、 前記制御手段は、前記濃度測定手段による濃度の測定の
結果、アンモニア濃度に対する過酸化水素濃度の比が前
記洗浄用薬液の当初のアンモニア濃度に対する過酸化水
素濃度の比以下であるときには、前回もしくは前々回の
測定時に純水を補充したか、または、過酸化水素濃度が
前回もしくは前々回の測定結果に比べて上昇している場
合にのみ過酸化水素水を補充し、それ以外の場合には前
記洗浄槽内の洗浄用薬液の交換のためのアラームを発す
る請求項６に記載の洗浄用薬液の濃度管理方法。7. The control means stores the replenishment history and the concentration of hydrogen peroxide at the time of the previous and second previous concentration measurements. The control means stores the excess concentration with respect to the ammonia concentration as a result of the concentration measurement by the concentration measurement means. When the ratio of the concentration of hydrogen oxide is equal to or less than the ratio of the concentration of hydrogen peroxide to the initial concentration of ammonia in the cleaning chemical solution, pure water was replenished at the previous or second-last measurement, or the concentration of hydrogen peroxide was set at the previous or second-last measurement. 7. The cleaning according to claim 6, wherein the hydrogen peroxide solution is replenished only when the temperature is higher than the measurement result, and an alarm for replacing the cleaning chemical in the cleaning tank is generated otherwise. How to control the concentration of liquid medicine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33220696A JP2888217B2 (en) | 1996-12-12 | 1996-12-12 | Method for controlling concentration of cleaning chemical solution and silicon wafer cleaning apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33220696A JP2888217B2 (en) | 1996-12-12 | 1996-12-12 | Method for controlling concentration of cleaning chemical solution and silicon wafer cleaning apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10172940A JPH10172940A (en) | 1998-06-26 |
| JP2888217B2 true JP2888217B2 (en) | 1999-05-10 |
Family
ID=18252371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33220696A Expired - Lifetime JP2888217B2 (en) | 1996-12-12 | 1996-12-12 | Method for controlling concentration of cleaning chemical solution and silicon wafer cleaning apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2888217B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100813018B1 (en) * | 2001-06-02 | 2008-03-13 | 삼성전자주식회사 | Apparatus mixing ingredients of cleaning liquid |
| JP2004006819A (en) | 2002-04-26 | 2004-01-08 | Nec Electronics Corp | Method for manufacturing semiconductor device |
| JP5357509B2 (en) | 2008-10-31 | 2013-12-04 | 株式会社日立ハイテクノロジーズ | Inspection device, inspection method, and calibration system for inspection device |
| JP2021068791A (en) * | 2019-10-22 | 2021-04-30 | 株式会社デンソー | Method for manufacturing semiconductor device |
| CN113257660B (en) * | 2021-04-13 | 2022-09-23 | 上海中欣晶圆半导体科技有限公司 | Method for cleaning silicon wafer with no-end treatment corresponding to edge |
-
1996
- 1996-12-12 JP JP33220696A patent/JP2888217B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10172940A (en) | 1998-06-26 |
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