【発明の名称】無電解めっき装置及び無電解めっき方法
【特許請求の範囲】
【請求項１】無電解めっき処理槽を具備し、該無電解めっき処理槽内に無電解めっき液を収容すると共に、該無電解めっき液に被めっき基板を浸漬し、該被めっき基板に無電解めっきを施す無電解めっき装置において、
めっき液循環槽、めっき液循環ポンプ、切換弁を具備し、前記無電解めっき処理槽に被めっき基板を配置すると共に、該めっき液循環槽から無電解めっき液を供給し、該無電解めっき液を外気と完全に遮断し、密閉状態で該被めっき基板の表面に無電解めっき膜を形成することを特徴とする無電解めっき装置。
【請求項２】請求項１に記載の無電解めっき装置において、
前記無電解めっき処理槽に給水口、排水口を設け、該無電解めっき処理槽内に配置された被めっき基板を外気に曝すことなく、めっき処理及び水洗処理を連続して実施できるように構成したことを特徴とする無電解めっき装置。
【請求項３】請求項１又は２に記載の無電解めっき装置において、
前記無電解めっき処理槽に不活性ガス供給源及び真空ポンプを接続し、めっき液及び水洗水を該無電解めっき処理槽から急速に排出することができるように構成したことを特徴とする無電解めっき装置。
【請求項４】請求項１又は２又は３に記載の無電解めっき装置において、
前記無電解めっき処理槽にハロゲンランプ又はマイクロウエーブ発生器を設け、前記めっき処理、水洗処理及び乾燥処理を連続して実施できるように構成したことを特徴とする無電解めっき装置。
【請求項５】基板に無電解めっきを施す無電解めっき方法において、
前記基板を外気に曝すことなくめっき処理を行い、次に該基板を外気に曝すことなく水洗処理することを特徴とする無電解めっき方法。
【請求項６】請求項５に記載の無電解めっき方法において、
前記水洗処理後、前記基板の乾燥処理を外気に曝すことなく実施することを特徴とする無電解めっき方法。
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】
本発明は半導体ウエハー及び基板等の被めっき基板に金属めっきを施す無電解めっき装置及び無電解めっき方法に関するものである。
【０００２】
【従来の技術】
従来、この種のめっき装置においては、めっき処理、水洗処理及び乾燥処理をそれぞれ専用の処理槽で実施するように構成している。そのため処理槽間を被めっき品を搬送する場合、被めっき品をめっき液や洗浄水で濡れた状態で大気に曝すことが不可避であった。
【０００３】
【発明が解決しようとする課題】
上記のように従来の無電解めっき装置では、被めっき品をめっき液や洗浄水で濡れた状態で大気に曝すことが不可避であったため、下記のような不都合が生じる。
【０００４】
（１）被めっき品の表面に残存・付着しているめっき液による局部的めっきにより不均一な膜厚のめっき膜が形成される。
【０００５】
（２）被めっき品の表面に付着した液質に依存する無用の酸化・還元・腐食反応等が発生する。
【０００６】
（３）被めっき品の表面に局所的に付着する液の乾燥等に起因する汚染やシミが発生する。
【０００７】
【課題を解決するための手段】
本発明は上述の点に鑑みてなされたもので、上記問題点を除去し、均一な膜厚のめっき膜が形成でき、且つ付着した液質に依存する無用の酸化・還元・腐食反応、局所的に付着する液の乾燥等に起因する汚染やシミが発生することのない無電解めっき装置及び無電解めっき方法を提供することを目的とする。
【０００８】
上記課題を解決するため請求項１に記載の発明は、無電解めっき処理槽を具備し、該無電解めっき処理槽内に無電解めっき液を収容すると共に、該無電解めっき液に被めっき基板を浸漬し、該被めっき基板に無電解めっきを施す無電解めっき装置において、めっき液循環槽、めっき液循環ポンプ、切換弁を具備し、無電解めっき処理槽に被めっき基板を配置すると共に、該めっき液循環槽から無電解めっき液を供給し、該無電解めっき液を外気と完全に遮断し、密閉状態で該被めっき基板の表面に無電解めっき膜を形成することを特徴とする。
【０００９】
上記のように、無電解めっき液を外気と完全に遮断し、密閉状態で該被めっき基板の表面に無電解めっき膜を形成するので、被めっき基板の表面に付着しためっき液の液質に依存する無用の酸化・還元・腐食反応等が発生することがない。
【００１０】
また、請求項２に記載の発明は、請求項１に記載の無電解めっき装置において、無電解めっき処理槽に給水口、排水口を設け、該無電解めっき処理槽内に配置された被めっき基板を外気に曝すことなく、めっき処理及び水洗処理を連続して実施できるように構成したことを特徴とする。
【００１１】
上記のように無電解めっき処理槽内に配置された被めっき基板を外気に曝すことなく、めっき処理及び水洗処理を連続して実施するので、被めっき基板の表面に残存・付着しているめっき液による局部的めっきにより不均一な膜厚のめっき膜が形成されることがなくなる。
【００１２】
また、請求項３に記載の発明は、請求項１又は２に記載の無電解めっき装置において、無電解めっき処理槽に不活性ガス供給源及び真空ポンプを接続し、めっき液及び水洗水を該無電解めっき処理槽から急速に排出することができるように構成したことを特徴とする。
【００１３】
上記のようにめっき液及び水洗水を該無電解めっき処理槽から急速に排出することにより、被めっき基板の表面に付着した液質に依存する無用の酸化・還元・腐食反応等の発生が抑制されると共に、被めっき基板の表面に残存・付着しているめっき液による局部的めっきによる不均一な膜厚のめっき膜の形成も抑制される。
【００１４】
また、請求項４に記載の発明は、請求項１又は２又は３に記載の無電解めっき装置において、無電解めっき処理槽にハロゲンランプ又はマイクロウエーブ発生器を設け、めっき処理、水洗処理及び乾燥処理を連続して実施できるように構成したことを特徴とする。
【００１５】
上記のようにめっき処理、水洗処理及び乾燥処理を連続して実施できることにより、上記作用効果は被めっき基板の表面に付着した液質に依存する無用の酸化・還元・腐食反応等及び被めっき基板の表面に残存・付着しているめっき液による局部的めっきによる不均一な膜厚のめっき膜の形成が更に抑制される。また、被めっき基板の表面に局所的に付着する液の乾燥等に起因する汚染やシミの発生も抑制される。
【００１６】
請求項５に記載の発明は、基板に無電解めっきを施す無電解めっき方法において、基板を外気に曝すことなくめっき処理を行い、次に該基板を外気に曝すことなく水洗処理することを特徴とする。
【００１７】
上記のように基板を外気に曝すことなくめっき処理を行い、次に該基板を外気に曝すことなく水洗処理するので、被めっき基板の表面に残存・付着しているめっき液による局部的めっきにより不均一な膜厚のめっき膜が形成されることがなくなる。
【００１８】
請求項６に記載の発明は、請求項５に記載の無電解めっき方法において、水洗処理後、基板の乾燥処理を外気に曝すことなく実施することを特徴とする。
【００１９】
上記のように水洗処理後、基板の乾燥処理を外気に曝すことなく実施するので、被めっき基板の表面に局所的に付着する液の乾燥等に起因する汚染やシミの発生も抑制される。
【００２０】
【発明の実施の形態】
以下、本発明の実施の形態例を図面に基づいて説明する。図１は本発明に係る無電解めっき装置の構成を示す図である。図１において、１０は無電解めっき処理槽であり、該無電解めっき処理槽１０は内部に無電解めっき液等を収容する空間１２が形成された槽本体１１、槽本体１１の空間１２を閉塞する蓋体１３、及び該蓋体１３の上部に配置したハロゲンランプ又はマイクロウエーブ発生器１４を具備する。
【００２１】
１５はめっき液循環槽であり、該めっき液循環槽１５にはヒータ１６が配置されている。１７はめっき液循環ポンプ、１８は真空ポンプ、１９は気水分離器、Ｖ1〜Ｖ8はそれぞれ開閉弁である。
【００２２】
上記構成の無電解めっき装置において、常時は開閉弁Ｖ1を開くと共に開閉弁Ｖ2、Ｖ3を閉じ、めっき液循環ポンプ１７を運転し、めっき液循環槽１５内の無電解めっき液Ｑ1を循環させておく、この時ヒータ１６により、無電解めっき液Ｑ1の液温が所定の温度になるようにする。
【００２３】
無電解めっき処理槽１０の槽本体１１には無電解めっき液及び洗浄液を供給排出する給水口１１ａ、排水口１１ｂが設けられており、無電解めっき液及び洗浄液を供給排出できるようになっている。また、空間１２の底部には被めっき基板２０が配置されており、該空間１２には開閉弁Ｖ4を通して窒素（Ｎ2）ガス等の不活性ガスを充填できるようになっている。
【００２４】
被めっき基板２０に無電解めっき処理を施すには、開閉弁Ｖ4、Ｖ5、Ｖ7、Ｖ8を閉じ、開閉弁Ｖ6を開いて、真空ポンプ１８を起動し、槽本体１１の空間１２の窒素（Ｎ2）ガス等の不活性ガスを抜きとる。該空間１２の真空度が所定の値になったら、この状態で開閉弁Ｖ1、Ｖ6を閉じ、開閉弁Ｖ2、Ｖ5を開いて、めっき液循環槽１５内の無電解めっき液Ｑ1をめっき液循環ポンプ１７により、槽本体１１の空間１２に充填、循環する。無電解めっき液Ｑ1が充填、循環された状態で所定の時間が経過すると被めっき基板２０の表面に所定膜厚の無電解めっき膜が形成される。
【００２５】
無電解めっき膜の形成が終了したら、開閉弁Ｖ1を開くと共に開閉弁Ｖ2を閉じて無電解めっき液Ｑ1を上記のように循環させる。続いて、開閉弁Ｖ4を開いて窒素（Ｎ2）ガス等の不活性ガスを空間１２に供給すると共に開閉弁Ｖ8を開いてめっき液循環槽１５内を減圧することにより、槽本体１１の空間１２内の無電解めっき液Ｑ1を速やかにめっき液循環槽１５に戻す（押し出す）。
【００２６】
槽本体１１の空間１２内の無電解めっき液Ｑ1の全部がめっき液循環槽１５に戻ったら、開閉弁Ｖ4、Ｖ5、Ｖ8を閉じ、開閉弁Ｖ6を開いて、空間１２内のガスを除去する。続いて、開閉弁Ｖ3、Ｖ7を開き、開閉弁Ｖ3を通して洗浄水（Ｈ2Ｏ）等の洗浄液を槽本体１１の空間１２内に供給し被めっき基板２０の表面を洗浄する。この時、洗浄済みの洗浄液は開閉弁Ｖ7を通して排水される。洗浄が終了したら、開閉弁Ｖ3を閉じ、空間１２内の洗浄液を排水する。この時例えば開閉弁Ｖ4を開いて窒素（Ｎ2）ガス等の不活性ガスを空間１２に充填する。これにより空間１２内の洗浄液は速やかに排出される。
【００２７】
続いて、開閉弁Ｖ4、Ｖ7を閉じ開閉弁Ｖ6を開き、槽本体１１の空間１２内の不活性ガスを排気する。この時ハロゲンランプ又はマイクロウエーブ発生器１４を起動し、被めっき基板２０の表面にハロゲンランプ光又はマイクロウエーブを照射する。これにより、被めっき基板２０に付着した洗浄液は蒸発し、真空ポンプ１８により排気される。この排気は気水分離器１９を通って水分が除去され所定の排気口に放出される。上記乾燥処理の終了した被めっき基板２０を槽本体１１から搬出することにより、めっき処理は終了する。
【００２８】
上記構成の無電解めっき装置によれば、槽本体１１の空間１２の空間に搬入された被めっき基板２０はめっき処理から洗浄及び乾燥処理が終了するまで、大気に曝されることなく、処理できるので、上記（１）乃至（３）の不都合、即ち、「被めっき基板の表面に残存・付着しているめっき液による局部的めっきによる不均一な膜厚のめっき膜の形成」、「被めっき基板の表面に付着した液質に依存する無用の酸化・還元・腐食反応等の発生」、「被めっき基板の表面に局所的に付着する液の乾燥等に起因する汚染やシミの発生」の不都合がなくなる。
【００２９】
半導体ウエハや基板等の被めっき基板２０には配線用の微細な溝や孔が形成されており、該微細溝や孔に銅等の高導電性の金属を埋め込んで配線を形成するのであるが、上記構成の無電解めっき装置はこのような微細溝や孔を銅等の金属めっきで埋め込むのに好適である。
【００３０】
上記構成の無電解めっき装置を用いて、銅の無電解めっきを施す場合は、無電解めっき液としては例えば下記のものを用いる。
硫酸銅（ＣｕＳＯ4・５Ｈ2Ｏ） ３〜１０ｇ／ｌ
錯化剤（エチレンジアミン４酢酸） １０〜２０ｇ／ｌ
還元剤（ホルマリン） 微量
ＰＨ調整剤（アルカリ溶液） 適量
添加剤 微量
【００３１】
【発明の効果】
以上説明したように請求項１に記載の発明によれば、無電解めっき液を外気と完全に遮断し、密閉状態で該被めっき基板の表面に無電解めっき膜を形成するので、無電解めっき液が外気に曝されることにより、被めっき基板の表面に付着した液質に依存する無用の酸化・還元・腐食反応等が発生するという不都合を解消することができる。
【００３２】
請求項２に記載の発明によれば、無電解めっき処理槽内に配置された被めっき基板を外気に曝すことなく、めっき処理及び水洗処理を連続して実施するので、被めっき基板の表面に残存・付着しているめっき液による局部的めっきにより不均一な膜厚のめっき膜が形成されるという不都合を解消できる。また、被めっき基板の表面に付着した液質に依存する無用の酸化・還元・腐食反応等が発生するという不都合も抑制することができる。
【００３３】
請求項３に記載の発明によれば、無電解めっき処理槽に不活性ガス供給源及び真空ポンプを接続し、めっき液及び水洗水を該無電解めっき処理槽から急速に排出することができるようにしたので、上記不都合が極力抑制されると共に、処理が迅速となる。
【００３４】
請求項４に記載の発明によれば、無電解めっき処理槽にハロゲンランプ又はマイクロウエーブ発生器を設け、めっき処理、水洗処理及び乾燥処理を連続して実施できるように構成したので、上記不都合が極力抑制されると共に、被めっき基板の表面に局所的に付着する液の乾燥等に起因する汚染やシミの発生も抑制することができる。
【００３５】
請求項５に記載の発明によれば、基板を外気に曝すことなくめっき処理を行い、次に該基板を外気に曝すことなく水洗処理するので、被めっき基板の表面に残存・付着しているめっき液による局部的めっきにより不均一な膜厚のめっき膜が形成されることがなくなる。
【００３６】
請求項６に記載の発明によれば、水洗処理後、基板の乾燥処理を外気に曝すことなく実施するので、被めっき基板の表面に局所的に付着する液の乾燥等に起因する汚染やシミの発生も抑制される。
【図面の簡単な説明】
【図１】本発明に係る無電解めっき装置の構成を示す図である。
【符号の説明】
１０ 無電解めっき処理槽
１１ 槽本体
１２ 空間
１３ 蓋体
１４ ハロゲンランプ又はマイクロウエーブ発生器
１５ めっき液循環槽
１６ ヒータ
１７ めっき液循環ポンプ
１８ 真空ポンプ
１９ 気水分離器
２０ 被めっき基板
Ｖ1〜Ｖ8 開閉弁Patent application title: Electroless plating apparatus and electroless plating method
1. An electroless plating treatment tank is provided, an electroless plating solution is contained in the electroless plating treatment tank, and a substrate to be plated is immersed in the electroless plating solution, and no plating solution is formed on the substrate to be plated. In an electroless plating apparatus that performs electrolytic plating,
A plating solution circulation tank, a plating solution circulation pump, and a switching valve are provided, and a substrate to be plated is disposed in the electroless plating treatment tank, and an electroless plating solution is supplied from the plating solution circulation tank. An electroless plating film formed on the surface of the substrate to be plated in a sealed state.
2. The electroless plating apparatus according to claim 1,
The electroless plating treatment tank is provided with a water supply port and a drainage port, and the plating treatment and the water washing treatment can be continuously performed without exposing the substrate to be plated disposed in the electroless plating treatment tank to the open air. An electroless plating apparatus characterized in that
3. The electroless plating apparatus according to claim 1 or 2
An inert gas supply source and a vacuum pump are connected to the electroless plating treatment tank so that the plating solution and the flush water can be rapidly discharged from the electroless plating treatment tank. Plating equipment.
4. The electroless plating apparatus according to claim 1, 2 or 3.
An electroless plating apparatus comprising: a halogen lamp or a microwave generator provided in the electroless plating tank so that the plating process, the water washing process and the drying process can be performed continuously.
5. An electroless plating method for electrolessly plating a substrate, comprising:
An electroless plating method comprising: performing plating treatment without exposing the substrate to the open air, and then washing the substrate without exposing the substrate to the open air.
6. The electroless plating method according to claim 5,
The electroless-plating method characterized by implementing the drying process of the said board | substrate, without exposing to the open air after the said water washing process.
Detailed Description of the Invention
[0001]
Field of the Invention
The present invention relates to an electroless plating apparatus and an electroless plating method for metal plating a substrate to be plated such as a semiconductor wafer and a substrate.
[0002]
[Prior Art]
Conventionally, in this type of plating apparatus, the plating treatment, the water washing treatment, and the drying treatment are each performed in a dedicated treatment tank. Therefore, when conveying a to-be-plated product between processing tanks, it was unavoidable to expose a to-be-plated product to the air in the state wet with plating solution and washing water.
[0003]
[Problems to be solved by the invention]
As described above, in the conventional electroless plating apparatus, it is inevitable to expose the product to be plated to the air in a wet state with a plating solution or washing water, and the following problems occur.
[0004]
(1) A plated film having a non-uniform film thickness is formed by local plating with a plating solution remaining or adhering to the surface of a product to be plated.
[0005]
(2) Unwanted oxidation / reduction / corrosion reaction occurs depending on the quality of liquid adhering to the surface of the article to be plated.
[0006]
(3) Contamination or stains occur due to drying of the solution locally attached to the surface of the article to be plated.
[0007]
[Means for Solving the Problems]
The present invention has been made in view of the above-mentioned point, and can eliminate the above-mentioned problems, can form a plating film having a uniform film thickness, and useless oxidation / reduction / corrosion reaction depending on the adhering liquid, local It is an object of the present invention to provide an electroless plating apparatus and an electroless plating method free from the occurrence of contamination and stains caused by the drying of a solution to be deposited.
[0008]
In order to solve the above-mentioned subject, the invention according to claim 1 comprises an electroless plating treatment tank, accommodates an electroless plating solution in the electroless plating treatment tank, and a substrate to be plated with the electroless plating solution. In the electroless plating apparatus for immersing the substrate to be plated by electroless plating, the plating solution circulation tank, the plating solution circulation pump, and the switching valve are provided, and the substrate to be plated is disposed in the electroless plating treatment tank An electroless plating solution is supplied from the plating solution circulation tank, the electroless plating solution is completely shut off from the outside air, and an electroless plating film is formed on the surface of the substrate in a sealed state.
[0009]
As described above, since the electroless plating solution is completely shut off from the outside air and the electroless plating film is formed on the surface of the substrate to be plated in a sealed state, the liquid quality of the plating solution attached to the surface of the substrate to be plated There is no occurrence of unnecessary oxidation / reduction / corrosion reaction, etc. depending on.
[0010]
The invention according to claim 2 is the electroless plating apparatus according to claim 1, wherein the electroless plating treatment tank is provided with a water supply port and a drainage port, and the plating object is disposed in the electroless plating treatment tank. It is characterized in that the plating process and the water washing process can be carried out continuously without exposing the substrate to the outside air.
[0011]
As described above, since the plating process and the water washing process are continuously performed without exposing the substrate to be plated, which is disposed in the electroless plating treatment tank, to the outside air, the plating remaining or adhering to the surface of the substrate to be plated It is not possible to form a plating film having an uneven film thickness by local plating with a liquid.
[0012]
The invention according to claim 3 relates to the electroless plating apparatus according to claim 1 or 2, wherein an inert gas supply source and a vacuum pump are connected to the electroless plating treatment tank, and a plating solution and washing water are used. It is characterized in that it can be rapidly discharged from the electroless plating treatment tank.
[0013]
By rapidly discharging the plating solution and the washing water from the electroless plating treatment tank as described above, the occurrence of useless oxidation / reduction / corrosion reaction depending on the quality of the liquid adhering to the surface of the substrate to be plated is suppressed. At the same time, formation of a plating film having a nonuniform film thickness by local plating with the plating solution remaining or adhering to the surface of the substrate to be plated is also suppressed.
[0014]
The invention according to claim 4 is the electroless plating apparatus according to claim 1 or 2, wherein the electroless plating treatment tank is provided with a halogen lamp or a microwave generator to perform plating treatment, water washing treatment and drying. It is characterized in that the processing can be performed continuously.
[0015]
As described above, since the plating treatment, the water washing treatment and the drying treatment can be carried out continuously, the above-mentioned effects depend on the quality of liquid adhering to the surface of the substrate to be plated, useless oxidation / reduction / corrosion reaction etc. and the substrate to be plated The formation of a plating film of nonuniform thickness by local plating with a plating solution remaining or adhering to the surface of the above is further suppressed. In addition, the occurrence of contamination or stain due to drying of the solution locally attached to the surface of the substrate to be plated is also suppressed.
[0016]
The invention according to claim 5 is characterized in that in the electroless plating method in which the substrate is subjected to electroless plating, the plating treatment is performed without exposing the substrate to the open air, and then the water washing treatment is performed without exposing the substrate to the open air. I assume.
[0017]
As described above, plating is performed without exposing the substrate to the outside air, and then the substrate is washed with water without exposing it to the outside air, so local plating with a plating solution remaining or adhering to the surface of the substrate to be plated The plating film having an uneven film thickness is not formed.
[0018]
The invention according to claim 6 is characterized in that, in the electroless plating method according to claim 5, the substrate is dried without being exposed to the air after the water washing treatment.
[0019]
As described above, since the substrate is dried without being exposed to the air after the water washing treatment, the occurrence of contamination or stains due to the drying of the solution locally attached to the surface of the substrate to be plated is also suppressed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 is a view showing the configuration of an electroless plating apparatus according to the present invention. In FIG. 1, 10 is an electroless plating treatment tank, and the electroless plating treatment tank 10 blocks the tank body 11 in which a space 12 for containing an electroless plating solution is formed and the space 12 of the tank body 11 And a halogen lamp or microwave generator 14 disposed on the top of the lid 13.
[0021]
Reference numeral 15 denotes a plating solution circulation tank, and a heater 16 is disposed in the plating solution circulation tank 15. 17 is a plating solution circulation pump, 18 is a vacuum pump, 19 is a gas-water separator, and V 1 to V 8 are on-off valves.
[0022]
In the electroless plating apparatus of the above configuration, normally closed on-off valve V 2, V 3 opens the on-off valve V 1, the plating solution circulating pump 17 was operated, the plating solution electroless plating circulating tank 15 solution Q 1 allowed to circulate, by this time the heater 16, the liquid temperature electroless plating solution Q 1 is set to be a predetermined temperature.
[0023]
The tank body 11 of the electroless plating treatment tank 10 is provided with a water supply port 11a and a drainage port 11b for supplying and discharging the electroless plating solution and the washing solution, so that the electroless plating solution and the washing solution can be supplied and discharged. . Further, the bottom of the space 12 is adapted to be filled with an inert gas such as nitrogen (N 2) gas through off valve V 4 in which is disposed to be plated substrate 20, the space 12.
[0024]
In order to perform the electroless plating process on the substrate 20 to be plated, the on-off valves V 4 , V 5 , V 7 and V 8 are closed, the on-off valve V 6 is opened, the vacuum pump 18 is activated, and the space of the tank body 11 is Inert gas such as 12 nitrogen (N 2 ) gas is removed. When the degree of vacuum of the space 12 reaches a predetermined value, the on-off valves V 1 and V 6 are closed in this state, the on-off valves V 2 and V 5 are opened, and the electroless plating solution Q in the plating solution circulation tank 15 is The space 1 of the tank 1 is filled and circulated by the plating solution circulation pump 17. Electroless plating solution Q 1 is filled, the electroless plating film having a predetermined thickness on the surface of the plated substrate 20 when a predetermined time has elapsed in a cyclic state is formed.
[0025]
When finished the formation of an electroless plated film, an electroless plating solution Q 1 by closing the on-off valve V 2 is circulated as described above opens the on-off valve V 1. Then, by reducing the pressure of the plating solution circulating tank 15 by opening the on-off valve V 4 nitrogen (N 2) an inert gas such as a gas by opening the on-off valve V 8 is supplied to the space 12, the tank body 11 returning the electroless plating solution to Q 1 space 12 of the immediately plating solution circulating tank 15 (push).
[0026]
Once all of the electroless plating solution to Q 1 space 12 of the tank main body 11 is returned to the plating solution circulating tank 15, closed-off valve V 4, V 5, V 8 , by opening the on-off valve V 6, the space 12 Remove the gas. Subsequently, the on-off valves V 3 and V 7 are opened, and a cleaning liquid such as cleaning water (H 2 O) is supplied into the space 12 of the tank body 11 through the on-off valve V 3 to clean the surface of the substrate 20. At this time, cleaned washing liquid is drained through the on-off valve V 7. After washing is completed, close the shutoff valve V 3, draining the cleaning liquid in the space 12. In this case for example by opening the on-off valve V 4 is filled with nitrogen (N 2) an inert gas such as a gas to the space 12. Thus, the cleaning liquid in the space 12 is quickly drained.
[0027]
Subsequently, the on-off valves V 4 and V 7 are closed, the on-off valve V 6 is opened, and the inert gas in the space 12 of the tank body 11 is exhausted. At this time, the halogen lamp or microwave generator 14 is activated, and the surface of the substrate 20 to be plated is irradiated with halogen lamp light or microwave. Thus, the cleaning solution attached to the substrate 20 to be plated is evaporated and evacuated by the vacuum pump 18. The exhaust gas is drained through the air-water separator 19 and discharged to a predetermined exhaust port. The plating process is completed by carrying out the substrate to be plated 20, for which the drying process has been completed, from the tank body 11.
[0028]
According to the electroless plating apparatus configured as described above, the substrate 20 carried into the space 12 of the tank body 11 can be processed without being exposed to the atmosphere until the cleaning and drying processes are completed from the plating process. Therefore, the disadvantages of the above (1) to (3) , that is, "formation of a plating film of non-uniform film thickness by local plating with a plating solution remaining or adhering to the surface of a substrate to be plated", Generation of unwanted oxidation / reduction / corrosion reaction depending on the quality of liquid adhering to the surface of the substrate and generation of contamination or stain caused by drying of the liquid locally adhering to the surface of the substrate to be plated There is no inconvenience.
[0029]
A fine groove or hole for wiring is formed in a substrate 20 to be plated such as a semiconductor wafer or substrate, and a highly conductive metal such as copper is embedded in the fine groove or hole to form a wiring. The electroless plating apparatus of the above configuration is suitable for embedding such fine grooves and holes by metal plating such as copper.
[0030]
When performing electroless plating of copper using the electroless plating apparatus of the said structure, the following are used as an electroless plating solution, for example.
Copper sulfate (CuSO 4 · 5 H 2 O) 3 to 10 g / l
Complexing agent (ethylenediaminetetraacetic acid) 10 to 20 g / l
Reductant (formalin) Trace PH adjuster (alkaline solution) Appropriate amount of additive Trace amount
[0031]
【Effect of the invention】
As described above, according to the first aspect of the present invention, the electroless plating solution is completely shut off from the open air, and the electroless plating film is formed on the surface of the substrate to be plated in a sealed state. By exposing the liquid to the outside air, it is possible to eliminate the disadvantage that the unwanted oxidation / reduction / corrosion reaction or the like depending on the liquid quality adhering to the surface of the substrate to be plated is generated.
[0032]
According to the second aspect of the present invention, since the plating process and the water washing process are continuously performed without exposing the substrate to be plated disposed in the electroless plating treatment tank to the outside air, it can be formed on the surface of the substrate to be plated It is possible to eliminate the disadvantage that a plating film having a non-uniform film thickness is formed by local plating with a remaining or adhering plating solution. In addition, it is possible to suppress the inconvenience that the unwanted oxidation / reduction / corrosion reaction occurs depending on the liquid quality adhering to the surface of the substrate to be plated.
[0033]
According to the third aspect of the present invention, the inert gas supply source and the vacuum pump can be connected to the electroless plating treatment tank so that the plating solution and the washing water can be rapidly discharged from the electroless plating treatment tank. Since the above-mentioned inconvenience is suppressed as much as possible, the processing becomes quick.
[0034]
According to the invention as set forth in claim 4, the electroless plating treatment bath is provided with a halogen lamp or a microwave generator so that the plating treatment, the water washing treatment and the drying treatment can be carried out continuously. While being suppressed as much as possible, it is also possible to suppress the occurrence of contamination or stain due to the drying of the solution locally attached to the surface of the substrate to be plated.
[0035]
According to the fifth aspect of the present invention, the plating process is performed without exposing the substrate to the air, and then the water washing process is performed without exposing the substrate to the air, so that the substrate remains or adheres to the surface of the substrate It is not possible to form a plating film having a nonuniform film thickness by local plating with a plating solution.
[0036]
According to the sixth aspect of the present invention, after the water washing process, the drying process of the substrate is carried out without being exposed to the outside air, so that contamination or stain caused by the drying of the solution locally attached to the surface of the substrate to be plated. Occurrence is also suppressed.
Brief Description of the Drawings
FIG. 1 is a view showing a configuration of an electroless plating apparatus according to the present invention.
[Description of the code]
DESCRIPTION OF SYMBOLS 10 Electroless-plating processing tank 11 tank main body 12 space 13 lid 14 halogen lamp or microwave generator 15 plating solution circulation tank 16 heater 17 plating solution circulation pump 18 vacuum pump 19 steam / water separator 20 substrate to be plated V 1 to V 8 on- off valve