JP2004300462A

JP2004300462A - Plating method and plating apparatus

Info

Publication number: JP2004300462A
Application number: JP2003091751A
Authority: JP
Inventors: Rei Kokai; 冷黄海; Yokou Kaku; 誉綱郭; Fumio Kuriyama; 文夫栗山
Original assignee: Ebara Corp
Current assignee: Ebara Corp
Priority date: 2003-03-28
Filing date: 2003-03-28
Publication date: 2004-10-28

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for plating a substrate with high reliability, which solves the unevenness of a flow rate in a plating solution and of a current density, to improve the thickness uniformity of a plated film and to plate the substrate at a high rate, and to provide an apparatus therefor. <P>SOLUTION: This plating method comprises plating the surface W1 to be plated of the substrate W immersed in a plating solution Q, while rotating the substrate of a vertically erected state; and making a part of a shaft 61 installed on a substrate holder 60 for holding the substrate W projecting from the sidewall of a plating tank 10 toward the outside, noncontact with the sidewall of the plating tank 10, to prevent the formation of particles and crystals of the plating solution due to the contact. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、基板の被めっき処理面にめっきを施すめっき方法及びめっき装置、特に半導体ウエハ等の被めっき処理面に設けられた微細な配線用溝やホール、レジスト開口部にめっき膜を形成したり、半導体ウエハの被めっき処理面に半導体チップと基板とを電気的に接続するバンプ（突起状電極）を形成するめっき方法及びめっき装置に関するものである。
【０００２】
【従来の技術】
従来、例えばＴＡＢ（ＴａｐｅＡｕｔｏｍａｔｅｄＢｏｎｄｉｎｇ）やフリップチップにおいては、配線が形成された半導体チップの表面の所定箇所（電極）に金、銅、はんだ、或いはニッケル、更にはこれらを多層に積層した突起状接続電極（バンプ）を形成し、このバンプを介して基板電極やＴＡＢ電極と電気的に接続することが広く行われている。このバンプの形成方法としては、電解めっき法、蒸着法、印刷法、ボールバンプ法といった種々の手法があるが、半導体チップのＩ／Ｏ数の増加、細ピッチ化に伴い、微細化が可能で性能が比較的安定している電解めっき法が多く用いられるようになってきている。
【０００３】
ここで電解めっき法は、半導体ウエハ等の基板の被めっき処理面を下向き（フェースダウン）にして水平に置き、めっき液を下から噴き上げてめっきを施す噴流式又はカップ式と、めっき槽の中に基板を垂直に立て、めっき液をめっき槽の下から注入しオーバーフローさせつつ基板をめっき液中に浸漬させてめっきを施すディップ式とに大別される。ディップ方式を採用した電解めっき法において基板を垂直に立ててめっきを行うのは、基板の被めっき処理面上に生じる気泡の除去が容易に行えるようにすることと、基板の被めっき処理面上にパーティクル等が付着しにくくするためである。基板を垂直に立ててめっきを行う電解めっき法によれば、高速めっきを行うときの激しい還元反応による気泡を容易に脱泡できるので、高速めっきに好適である。
【０００４】
ところで上記従来のディップ方式を採用した電解めっき装置にあっては、半導体ウエハ等の基板をその外周端面と裏面をシールし表面（被めっき処理面）を露出させて着脱自在に保持する基板ホルダを備え、この基板ホルダを基板ごとめっき液中に浸漬して基板の被めっき処理面のめっきを行うようにしている。
【０００５】
しかしながら上記従来のディップ方式を採用した電解めっき法にあっては、基板をめっき槽のめっき液中に垂直に立てた状態のまま浸漬して、めっき液をめっき槽の下部から上方向に向けて流すので、注入しためっき液は常に基板の被めっき処理面の下部から上部に向けて供給されることとなり、このため基板の被めっき処理面の上部と下部とでめっき液の流速ムラが生じ、基板の被めっき処理面の上部と下部とでめっきの条件が微妙に異なり、基板の被めっき処理面の場所に応じてめっきの膜厚に微妙な違いが生じてしまうという問題点があった。また電流密度のムラもめっきの不均一性の原因となっていた。
【０００６】
【特許文献１】
特開２００２−３６３７９７号公報
【０００７】
【発明が解決しようとする課題】
本発明は上述の点に鑑みてなされたものでありその目的は、めっきの不均一性の原因となるめっき液の流速ムラや電流密度のムラを解消させて、めっき膜厚の均一性を高め、且つ高速にメッキすることが可能な信頼性の高い基板のめっき方法及びめっき装置を提供することにある。
【０００８】
【課題を解決するための手段】
本願の請求項１に記載の発明は、基板をめっき液に浸漬することで基板の被めっき処理面を電解又は無電解めっき処理するめっき方法において、めっき液中に浸漬した基板の被めっき処理面を上下方向に立てた状態で回転しながら電解又は無電解めっきすることを特徴とするめっき方法である。基板の被めっき処理面を上下方向に立てた状態でめっきを行うので、被めっき処理面上に付着する気泡を即座に排除でき、高速めっきを行うときの激しい還元反応による気泡を容易に脱泡でき、めっきの高速化が図れる。同時に、基板を回転しながらめっきするのでめっき欠け、めっき抜けがなく、めっき被膜の均一性が図れ、高品質のめっき被膜が得られる。
【０００９】
本願の請求項２に記載の発明は、基板をめっき槽のめっき液中に浸漬することで基板の被めっき処理面を電解又は無電解めっき処理するめっき方法において、前記基板を保持する基板ホルダに取り付けたシャフトをめっき槽の側壁から外部に突出する部分をめっき槽の側壁と非接触とすることで、接触によるパーティクルの発生やめっき液の結晶の発生を防止することを特徴とするめっき方法である。
シャフトとめっき槽の側壁とが非接触なので、シール構造が不要になってその構造を簡単にでき、まためっき槽の側壁とシャフトの隙間にめっき液を流すことでめっき液の結晶が生じず、さらに摺動部分がなくなるのでパーティクルが生じず、めっき液の汚染が防止できる。
【００１０】
本願の請求項３に記載の発明は、請求項２に記載のめっき方法であって、めっき槽の側壁とシャフトの非接触によって生じる隙間から漏れ出ためっき液をめっき槽内に循環させることを特徴とするめっき方法である。これによってめっき槽の側壁とシャフトの隙間から漏れ出ためっき液を循環でき、有効に利用できる。
【００１１】
本願の請求項４に記載の発明は、請求項２又は３に記載のめっき方法であって、めっき槽からめっき液をオーバーフローさせると共にオーバーフローしためっき液をめっき槽に循環させることを特徴とするめっき方法である。めっき液をオーバーフローすることで、大量のめっき液を基板の被めっき処理面に供給でき、めっきの高速化が図れる。
【００１２】
本願の請求項５に記載の発明は、めっき槽のめっき液中に基板を浸漬することで基板の被めっき処理面の電解又は無電解めっきを行うめっき装置において、めっき液中に浸漬した基板の被めっき処理面を上下方向に立てた状態で回転する回転駆動手段を具備することを特徴とするめっき装置である。基板の被めっき処理面を上下方向に立てた状態でめっきを行うので、被めっき処理面上に付着する気泡を即座に排除でき、高速めっきを行うときの激しい還元反応による気泡を容易に脱泡でき、めっきの高速化が図れる。同時に、基板を回転する回転駆動手段を設けたので、基板を回転しながらめっきすることができ、めっき欠け、めっき抜けがなく、めっき被膜の均一性が図れ、高品質のめっき被膜が得られる。
【００１３】
本願の請求項６に記載の発明は、めっき槽のめっき液中に基板を浸漬することで基板の被めっき処理面の電解又は無電解めっきを行うめっき装置において、めっき液中に浸漬した基板をその被めっき処理面を上下方向に立てた状態で保持する基板ホルダのシャフトをめっき槽の側壁からこの側壁と非接触状態で外部に突出したことを特徴とするめっき装置である。シャフトとめっき槽の側壁とが非接触なので、シール構造が不要になってその構造を簡単にでき、まためっき槽の側壁とシャフトの非接触によって生じる隙間からめっき液が漏れ出ることでめっき液の流れが生じてこの部分にめっき液の結晶が生じず、さらに摺動部分がなくなるのでパーティクルが生じず、めっき液の汚染が防止できる。
【００１４】
本願の請求項７に記載の発明は、請求項６に記載のめっき装置であって、前記めっき槽の側壁とシャフトの隙間から漏れ出ためっき液をめっき槽内に循環するめっき液循環手段を設けたことを特徴とするめっき装置である。これによってめっき槽の側壁とシャフトの隙間から漏れ出ためっき液を循環でき、有効に利用できる。
【００１５】
本願の請求項８に記載の発明は、請求項６に記載のめっき装置であって、前記シャフトには、めっき槽の外部においてシャフト及び基板ホルダを回転駆動する回転駆動手段を取り付けたことを特徴とするめっき装置である。これによってめっき液中に浸漬する基板ホルダ及び基板を容易に回転できる。
【００１６】
本願の請求項９に記載の発明は、請求項６に記載のめっき装置であって、前記めっき槽にはシャフト引き上げ用の切り欠き溝を設けると共に、切り欠き溝に挿入したシャフトの上部を塞ぐ液流れ防止体を着脱自在に取り付けたことを特徴とするめっき装置である。これによってシャフトのめっき槽への着脱が容易に行える。
【００１７】
本願の請求項１０に記載の発明は、請求項６に記載のめっき装置であって、前記シャフトのめっき槽の側壁から外部に突出した部分には、めっき槽の側壁とシャフトの隙間から漏れためっき液のシャフトの回転による飛び散りを防止するめっき液飛び散り防止部材を設置したことを特徴とするめっき装置である。これによってめっき液の飛び散りが効果的に防止できる。
【００１８】
本願の請求項１１に記載の発明は、請求項６に記載のめっき装置であって、前記基板ホルダの基板を保持する面がめっき液から引き上げられて水平となる位置まで、基板ホルダ及びシャフトを揺動する揺動手段を設けたことを特徴とするめっき装置である。これによって基板ホルダへの基板の着脱と、基板を装着した基板ホルダのめっき槽内ヘの挿入とが何れも容易に行える。
【００１９】
本願の請求項１２に記載の発明は、めっき槽のめっき液中に基板を浸漬することで基板の被めっき処理面の電解又は無電解めっきを行うめっき装置において、基板を保持した基板ホルダとこの基板ホルダに取り付けたシャフトとを揺動することで、基板ホルダに保持した基板をめっき液中に浸漬する基板めっき位置と、基板ホルダに保持した基板を前処理及び／又は後処理する基板処理位置とに移動する揺動手段を設けるとともに、前記基板処理位置に移動した基板ホルダ近傍に基板の前処理及び／又は後処理を行う基板処理装置を設置したことを特徴とするめっき装置である。これによって基板を基板ホルダに保持したまま、めっき処理と前処理及び／又は後処理を行うことができ、めっき装置と前処理装置及び／又は後処理装置を別々に設ける必要がなく、装置の小型化が図れるばかりか、コストダウンが図れる。
【００２０】
本願の請求項１３に記載の発明は、請求項１２に記載のめっき装置であって、前記基板めっき位置は、基板の被めっき処理面を上下方向に立てた状態でめっき液中に浸漬する位置であり、前記基板処理位置は、基板の被めっき処理面をめっき液から引き上げて水平とした位置であることを特徴とするめっき装置である。
【００２１】
本願の請求項１４に記載の発明は、請求項１２又は１３に記載のめっき装置であって、前記シャフトには、このシャフト及び基板ホルダを回転する回転駆動手段が取り付けられていることを特徴とするめっき装置である。
【００２２】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して詳細に説明する。
図１は本発明の一実施の形態にかかるめっき装置１の概略構成図である。同図に示すようにめっき装置１は、めっき槽１０の外周を囲むようにオーバーフロー槽２０を設けるとともに、めっき槽１０の内部にアノードホルダ３０に保持されたアノード３１と基板ホルダ６０に保持された基板Ｗとを対向して設置し、設置したアノード３１と基板Ｗの間に中間マスク４０とパドル５０とを設置し、一方オーバーフロー槽２０の外部には基板ホルダ６０に取り付けたシャフト６１を回転駆動する回転駆動手段７０と、めっき槽１０内にめっき液Ｑを循環するめっき液循環手段８０とを設置して構成されている。以下各構成部分について説明する。
【００２３】
めっき槽１０は上面が開放された箱形形状に形成され、めっき槽１０に溜めためっき液Ｑがめっき槽１０の上端辺よりオーバーフローするように構成されている。
【００２４】
アノード３１は円板状であってめっき液Ｑ中で上下方向に立てた状態となるようにアノードホルダ３０に保持されている。また中間マスク４０は基板Ｗの大きさに見合った中央孔４１を設けることで、基板Ｗの周辺部の電位を下げ、めっき膜の膜厚を基板Ｗの各部において均等化するようにしている。アノード３１と基板Ｗ間には電解めっきに必要な電流が流される。
【００２５】
パドル（掻き混ぜ棒）５０は基板Ｗの被めっき処理面Ｗ１に対して平行に往復移動（図１では紙面手前奥方向に平行移動）することで、基板Ｗの被めっき処理面に沿っためっき液Ｑの流れを被めっき処理面の全面でより均等にして被めっき処理面全体に亘ってより均一な膜厚のめっき膜を形成するものである。
【００２６】
基板ホルダ６０に保持された基板Ｗの外部に露出する被めっき処理面Ｗ１は、めっき液Ｑ中で上下方向（垂直方向）に立てた状態となるように設置されている。基板ホルダ６０の基板Ｗを保持した面の反対側の面からはシャフト６１が突出し、めっき槽１０の側壁とオーバーフロー槽２０の側壁とを貫通してその外部に突出し、カップリング６３によって回転駆動手段７０の回転軸７１に連結されている。シャフト６１がめっき槽１０の側壁を貫通する部分には、側壁の上端辺からシャフト６１を貫通する部分に至る切り欠き溝１１が設けられ、また切り欠き溝１１の外側面には切り欠き溝１１に挿入したシャフト６１の上部を塞ぐ液流れ防止体１５が上下方向に向けて着脱自在に取り付けられている。ここで図２（ａ）は切り欠き溝１１の部分をめっき槽１０の外側から見た要部側面図（図３の矢印Ａ方向から見た図、但しめっき液飛び散り防止部材６５の記載は省略）、図２（ｂ）は図２（ａ）の平面図、図２（ｃ）は液流れ防止体１５を取り外した状態を示す要部側面図である。同図に示すように切り欠き溝１１はシャフト６１の直径よりも少し大きい幅に形成され、また切り欠き溝１１の下端部分はシャフト６１の直径よりも少し大きい内径の半円形状とされ、これによってシャフト６１を切り欠き溝１１の内周辺に接触することなく上方向に引き上げることができるように構成されている。また切り欠き溝１１の両側には、上下方向に伸びるガイド溝１４，１４が設けられ、液流れ防止体１５の両側辺をガイドしながら上下動できるようにしている。液流れ防止体１５は矩形状の平板で構成され、その下辺中央にはシャフト６１の直径よりも少し大きい内径の半円形の凹部１７が設けられている。そして図２（ａ）に示すようにシャフト６１を切り欠き溝１１に挿入して液流れ防止体１５を取り付ければ、切り欠き溝１１の下端辺部分と凹部１７とによって形成される円形の開口内をシャフト６１が貫通した状態となるが、その際シャフト６１の周囲には円形の隙間１００が形成されてめっき槽１０の側壁及び液流れ防止体１５とシャフト６１とは非接触状態となる。
【００２７】
図１に戻ってシャフト６１のめっき槽１０の側壁から外部に突出している部分には、めっき液飛び散り防止部材６５が固定されている。図３はシャフト６１がめっき槽１０の側壁から外部に突出した部分近傍を示す要部拡大断面図である。同図においてめっき液飛び散り防止部材６５は略円板状の板体であり、その外周縁がめっき槽１０の側壁側に折り曲げられることで、前記隙間１００から漏れ出てくるめっき液Ｑがシャフト６１の回転による遠心力によって周囲に飛び散らないようにしている。
【００２８】
シャフト６１がオーバーフロー槽２０の側壁を貫通する部分にも、オーバーフロー槽２０の側壁の上端辺からシャフト６１を貫通する部分に至る切り欠き溝２１が設けられている。切り欠き溝２１はシャフト６１の直径よりも少し大きい幅に形成されており、これによってシャフト６１を切り欠き溝２１内に設置したときはもちろん、シャフト６１を上方向に引き上げる際もシャフト６１が切り欠き溝２１の内周辺に接触することのないように構成している。
【００２９】
オーバーフロー槽２０の外部に突出したシャフト６１の先端には、前述のようにカップリング６３によって回転駆動手段７０の回転軸７１がシャフト６１と一体に回転するように固定されている。回転駆動手段７０は電動機によって構成され、前記シャフト６１及び基板ホルダ６０を所定の回転数で回転駆動する。またこの回転駆動手段７０は軸ａ１を中心にして基板ホルダ６０及びシャフト６１を上方向に向かって揺動する揺動手段９５を具備している。即ち揺動手段９５は、回転駆動手段７０自体を中心（軸ａ１）にして図１に実線で示す位置、即ち基板ホルダ６０に保持した基板Ｗの被めっき処理面Ｗ１がめっき液Ｑ中で上下に垂直となる基板めっき位置から、図１に二点鎖線で示す位置、即ち基板ホルダ６０をめっき液Ｑから引き上げて基板Ｗが水平となる基板処理位置まで、基板ホルダ６０及びシャフト６１を揺動する。
【００３０】
なお基板処理位置まで移動した基板ホルダ６０の上部には洗浄装置（基板処理装置）２００が設置されている。洗浄装置２００は処理液供給手段（洗浄液供給手段）２０１の周囲に洗浄液の飛び散り防止用のカップ２０２を設置し、カップ２０２の外周下辺部にリング状の処理液収納凹部２０３を設け、処理液収納凹部２０３の所定位置にドレン管２０５を接続して構成されている。
【００３１】
めっき液循環手段８０はオーバーフロー槽２０の底面とリザーバタンク８５間を配管８１で接続し、またオーバーフロー槽２０のめっき液Ｑの最高水位位置とリザーバタンク８５間も配管８３で接続し、さらにめっき槽１０の底面とリザーバタンク８５間を配管８７で接続すると共にこの配管８７中に循環ポンプＰ及び恒温ユニット８９及びフィルタ９１を取り付けて構成されている。そして配管８１はオーバーフロー槽２０にオーバーフローしためっき液Ｑをリザーバタンク８５に回収し、配管８３はオーバーフロー槽２０内のめっき液Ｑの水位が最高水位よりも上昇しないようにし、配管８７は循環ポンプＰによってリザーバタンク８５内のめっき液Ｑをめっき槽１０の底面から供給する。
【００３２】
次に上記めっき装置１を用いて基板Ｗの被めっき処理面Ｗ１にめっき処理を行う工程を説明する。めっきの種類としては各種あり、例えば銅めっき、ニッケルめっき、はんだめっき、更には金めっき等においても同様に使用できる。まず図１に実線で示すように基板ホルダ６０とシャフト６１とをめっき槽１０内にセットする。このとき基板ホルダ６０に保持されている基板Ｗの被めっき処理面Ｗ１は、めっき槽１０内で上下方向に立てた状態となる。そして循環ポンプＰを駆動することでリザーバタンク８５内のめっき液Ｑが恒温ユニット８９でめっきに適した温度に調整され、さらにフィルタ９１でパーティクル等が除去された後にめっき槽１０に供給される。めっき槽１０内に供給されためっき液Ｑはめっき槽１０内を循環した後にめっき槽１０の上端辺からオーバーフローし、オーバーフロー槽２０に移動する。オーバーフロー槽２０内に溜まっためっき液Ｑは配管８１によってリザーバタンク８５に回収される。なおオーバーフロー槽２０内のめっき液Ｑの水位は配管８３によってその最高水位位置よりも上昇しないようにしている。
【００３３】
一方めっき槽１０内のめっき液Ｑの一部は、シャフト６１がメッキ槽１０の側壁から突出する部分に形成される隙間１００（図２（ａ）参照）からオーバーフロー槽２０に漏れる。
【００３４】
そしてパドル５０を基板Ｗの被めっき処理面Ｗ１に対して往復平行移動（図１の紙面手前奥方向に移動）することで基板Ｗの被めっき処理面Ｗ１に沿っためっき液Ｑの流れを被めっき処理面Ｗ１の全面でより均等にしながら、回転駆動手段７０によって基板ホルダ６０及び基板Ｗを回転（例えば５０回転／分）し、同時にアノード３１と基板Ｗ間に通電し、これによって基板Ｗの被めっき処理面Ｗ１上に電解めっきを行う。このときめっき液Ｑ中に浸漬した基板Ｗの被めっき処理面Ｗ１が上下方向に立てた状態となっているので、めっきの品質に悪影響を与える気泡の抜けが良い。このため高速めっきを行うときの激しい還元反応による気泡の脱泡が容易に図れ、高速にめっきすることが可能で信頼性の高いめっきが行える。ところで前述のように基板Ｗをめっき槽１０の中に上下に立てた状態のままめっき液Ｑをめっき槽１０の下から上方向に向けて流すと、めっき液Ｑは常に基板Ｗの被めっき処理面Ｗ１の下部から上部に向けて供給されることとなるため、基板Ｗの被めっき処理面Ｗ１の各部において流速ムラが生じ、基板Ｗの被めっき処理面Ｗ１の上部と下部とでめっきの条件が微妙に異なって被めっき処理面Ｗ１の場所に応じてめっきの膜厚に微妙な違いが生じてしまう恐れがある（被めっき処理面Ｗ１の下部のめっき膜厚が上部のめっき膜厚よりも厚くなってしまう）。また基板Ｗの被めっき処理面Ｗ１の各部の電流密度（電場分布）にもムラが生じる場合があった。しかしながら本実施の形態においては、基板Ｗのめっき時に基板Ｗを回転するので、基板Ｗの被めっき処理面Ｗ１の上部と下部が順次入れ替わり、これによって基板Ｗの被めっき処理面Ｗ１各部のめっきの条件（めっき液の流速と電流密度）が同一になりめっきの膜厚が均一になる。基板Ｗの回転速度はめっきの種類、基板Ｗの大きさ、めっき液Ｑの特性等によって異なるが、一般に０〜５００（回転／分）が好ましく、さらには０〜２００（回転／分）が好ましく、さらには０〜１００（回転／分）が好ましい。
【００３５】
ところで本実施の形態においては、シャフト６１がめっき槽１０の側壁を貫通して外部に突出しているが、もしこのめっき槽１０の側壁のシャフト６１が外部に突出する部分をシールしてめっき槽１０内のめっき液Ｑの漏れを防止したとすると、以下のような問題が生じる。即ちまずシャフト６１は回転するのでシールが困難であり、シール構造が複雑になってしまう。また例えシールしたとしても、シール部分に生じる狭い隙間にめっき液Ｑが滞留することでめっき液Ｑの結晶が生じてしまう。さらにシャフト６１が回転することでシール部分との摺動によるパーティクルが発生し、めっき液Ｑを汚染する恐れがある。そこで本実施の形態においては、シャフト６１がめっき槽１０の側壁を貫通する部分を非接触として隙間１００を設けることで、シール構造を不要として（言い換えれば少量のめっき液Ｑを漏らすことで流体抵抗によってシールすることによって）その構造を簡単にし、また隙間１００にめっき液Ｑを流すことでめっき液Ｑの結晶が生じることを防止し、さらに摺動部分がなくなるのでパーティクルが生じずめっき液Ｑの汚染を防止するようにしたのである。そしてこの隙間１００からめっき液Ｑが排出されるが、このめっき液Ｑはオーバーフロー槽２０に回収されてめっき液循環手段８０によってめっき槽１０に循環される。隙間１００から排出されためっき液Ｑはシャフト６１が回転することで周囲に飛び散ろうとするが、シャフト６１にはめっき液飛び散り防止部材６５が固定されているので、めっき液Ｑの飛び散りは防止される。
【００３６】
またオーバーフロー槽２０の側壁には切り欠き溝２１が設けられているが、オーバーフロー槽２０に溜まるめっき液Ｑは、配管８３を接続した位置（めっき液Ｑの最高水位）よりも上昇しないように構成されているので、前記切り欠き溝２１に至ることはない。またシャフト６１はオーバーフロー槽２０の側壁にも触れないので、この部分でパーティクルが生じてめっき液Ｑを汚染することもない。
【００３７】
以上のようにして基板Ｗのめっき処理が終了すれば、アノード３１と基板Ｗ間の通電を停止して電解めっきを終了した後、めっき槽１０内のめっき液Ｑを所定の低い水位となるまで抜き、液流れ防止体１５を図示しない駆動機構によって上方向に引き抜き、揺動手段９５を駆動して基板ホルダ６０及びシャフト６１を上方向に揺動し、基板ホルダ６０を図１に二点鎖線で示す基板処理位置に移動する。前記移動の際、シャフト６１はシャフト６１の直径よりも大きい幅寸法の切り欠き溝１１，２１内を通過するのでこれらに触れることはなく、パーティクルは生じない。
【００３８】
基板処理位置に移動した基板ホルダ６０の上部からは、二点鎖線で示すように洗浄装置２００が下降し、基板ホルダ６０の周囲をカップ２０２で覆い、この状態で基板ホルダ６０を回転しながら処理液供給手段２０１から基板Ｗの被めっき処理面Ｗ１に洗浄液（例えば純水）を噴射・供給して洗浄する。被めっき処理面Ｗ１を洗浄した後の洗浄液は、カップ２０２外周の処理液収納凹部２０３からドレン管２０５を介して排水される。洗浄が終了すれば洗浄装置２００は上昇し、下記する基板搬送ロボット３１３が基板ホルダ６０に保持した基板Ｗを取り出し、次の未処理の基板Ｗを基板ホルダ６０に装着する。そして回転駆動手段７０を中心にして基板ホルダ６０及びシャフト６１を下方向に揺動して基板ホルダ６０を図１に実線で示す基板めっき位置に移動し、液流れ防止体１５を図示しない駆動機構によって装着した後に前記と同様の工程でめっき処理を行っていく。
【００３９】
ところで上記めっき装置１において、処理液供給手段２０１が供給する薬液を前処理用の薬液とすれば、洗浄装置２００を基板の前処理装置に変更できる。また処理液供給手段２０１が供給する処理液を、洗浄液やそれ以外の薬液の複数種類とすれば、一台の処理液供給手段２０１によって複数種類の処理を行うことができる。例えば未処理の基板Ｗの被めっき処理面Ｗ１に対してまずこのめっき装置１の基板処理位置において前処理を行い、次に基板めっき位置においてめっき処理を行い、再び基板処理位置において洗浄処理などの後処理を行うことができる。つまり洗浄装置２００は前処理や後処理を行う基板処理装置として構成できる。
【００４０】
図４は前記めっき装置１を備えためっき処理機構３００の概略平面図である。同図に示すようにめっき処理機構３００は、基板搬送装置３１０の左右両側に三台ずつ全部で六台のめっき装置１を設置するとともに、基板搬送装置３１０の一端近傍に、基板Ｗを収納したカセットを搭載する三台のカセットテーブル３３０と、基板Ｗのオリフラやノッチ等の位置を所定の方向に合わせるアライナ３５０と、めっき処理後の基板Ｗを高速回転させて乾燥させるスピンドライヤ３７０とを設置して構成されている。基板搬送装置３１０はレール３１１上を基板搬送ロボット３１３が移動するように構成されており、基板搬送ロボット３１３はアーム３１５によって基板Ｗを前記各種装置間に移動する。
【００４１】
このように構成されためっき処理機構３００による一連の電解めっき処理を説明すると、まずカセットテーブル３３０に搭載したカセットから基板搬送ロボット３１３によって基板Ｗを一枚取り出し、アライナ３５０に載せてオリフラやノッチ等の位置を所定の方向に合わせる。次にアライナ３５０で方向を合わせた基板Ｗを基板搬送ロボット３１３によってめっき処理が終了している何れかのめっき装置１に搬送する。そして基板Ｗを搬送されためっき装置１は前述の方法で基板Ｗのめっき処理（前処理や洗浄処理等を含む）を行う。次にめっき装置１において前処理とめっき処理と洗浄処理とが終了した基板Ｗは、基板搬送ロボット３１３によってスピンドライヤ３７０に搬送されてスピンドライヤ３７０の高速回転によってスピンドライ（水切り）された後、基板搬送ロボット３１３によってカセットテーブル３３０のカセットに収納される。なお上記めっき装置１やその他の装置の台数や配置位置を任意に変更できることは言うまでもない。
【００４２】
また各めっき装置１でめっきする金属を任意に変更できることも言うまでもない。例えば各めっき装置１でめっきする金属を変更することで、基板Ｗの表面にニッケルめっき、銅めっき、はんだめっきを順次施して、ニッケル−銅−はんだからなる多層めっきによるバンプ等を一連の操作で形成することができる。多層めっきによるバンプとしては、このＮｉ−Ｃｕ−はんだの他に、Ｃｕ−Ａｕ−はんだ、Ｃｕ−Ｎｉ−はんだ、Ｃｕ−Ｎｉ−Ａｕ、Ｃｕ−Ｓｎ、Ｃｕ−Ｐｄ、Ｃｕ−Ｎｉ−Ｐｄ−Ａｕ、Ｃｕ−Ｎｉ−Ｐｄ、Ｎｉ−はんだ、Ｎｉ−Ａｕ等が挙げられる。はんだとしては高融点はんだと共晶はんだのどちらでもよい。またＳｎ−Ａｇの多層めっきによるバンプ、またはＳｎ−Ａｇ−Ｃｕの多層めっきによるバンプを形成し、アニールを施してこれらの合金化を図ることもできる。これにより従来のＳｎ−Ｐｂはんだとは異なり、Ｐｂフリーとして、α線による環境問題を解消できる。
【００４３】
図５は本発明の他の実施の形態にかかるめっき装置１−２の概略構成図である。同図において前記図１に示すめっき装置１と同一部分には同一符号を付してその詳細な説明は省略する。このめっき装置１−２において前記めっき装置１と相違する点は、アノード３１−２として不溶解性のメッシュ状のものを用い、配管８７のめっき槽１０側の端部をアノード３１−２の背面側に配置し、配管８７の複数に枝分れしたそれぞれの末端にノズル８８を取り付け、循環ポンプＰによってめっき槽１０内に供給されためっき液Ｑをアノード３１−２の背面側からアノード３１−２に向けて噴射するように構成した点である。このように構成すれば、めっき槽１０の下面からめっき液Ｑを供給する場合に比べて、基板Ｗの被めっき処理面Ｗ１に対してより均一にめっき液Ｑを供給することができ、基板Ｗを回転することによる作用と合わせて、さらに基板Ｗの被めっき処理面Ｗ１におけるめっき膜厚の面内均一性を高めることができる。
【００４４】
以上本発明の実施形態を説明したが、本発明は上記実施形態に限定されるものではなく、特許請求の範囲、及び明細書と図面に記載された技術的思想の範囲内において種々の変形が可能である。なお直接明細書及び図面に記載がない何れの形状や構造や材質であっても、本願発明の作用・効果を奏する以上、本願発明の技術的思想の範囲内である。例えば上記実施の形態ではアノード３１を設置してアノード３１と基板Ｗの間に通電することで電解めっきする場合を説明したが、アノード３１と中間マスク４０を設置しない無電解めっきにも本発明を適用することができる。
【００４５】
また上記実施の形態ではめっきの際に基板ホルダ６０及びシャフト６１を回転駆動したが、場合によっては基板ホルダ６０及びシャフト６１を静止した状態のままめっき処理しても良い。この場合、もしめっき槽１０の側壁とオーバーフロー槽２０の側壁とにシャフト６１の軸受を設けても、シャフト６１が回転しないので回転の摺動によるパーティクルは発生しないが、シャフト６１をめっき槽１０の側壁から着脱する際にはパーティクルが発生する恐れがあり、これを防止するためにシャフト６１がめっき槽１０の側壁とオーバーフロー槽２０の側壁とを貫通する部分を非接触とすることは効果的である。
【００４６】
また上記実施の形態では基板ホルダ６０に保持した基板Ｗをめっき槽１０内に設置したりめっき槽１０から取り外したりするため、基板ホルダ６０及びシャフト６１を揺動する揺動手段９５を設けたが、揺動手段９５を設けずに、カップリング６３の部分を切り離すことができるように構成することで、基板ホルダ６０及びシャフト６１の部分だけをカップリング６３の部分から切り離して、めっき槽１０から取り出したり、めっき槽１０に装着したりするように構成しても良い。
【００４７】
また上記実施の形態では液流れ防止体１５を上方向に引き抜くことでシャフト６１を挿入した切り欠き溝１１の上部の空間を開閉したが、液流れ防止体１５を水平方向に移動することでシャフト６１を挿入した切り欠き溝１１の上部の空間を開閉しても良い。
【００４８】
また上記実施の形態では基板Ｗを保持する基板ホルダ６０に取り付けたシャフト６１をめっき槽１０の側壁から外部に突出し、突出したシャフト６１に回転駆動手段７０を取り付けることで基板Ｗを回転したが、基板Ｗを回転する構造は他の種々の構造でも良く、要はめっき液Ｑに浸漬した基板Ｗの被めっき処理面Ｗ１を上下方向に立てた状態で回転することができる構造であれば、どのような構造の回転駆動手段であっても良い。
【００４９】
【発明の効果】
以上詳細に説明したように本発明によれば、めっきの不均一性の原因となるめっき液の流速ムラや電流密度のムラを解消でき、めっき膜厚の均一性が高められ、且つ高速にめっきすることが可能になる。
【００５０】
また本発明によれば、基板を保持する基板ホルダに取り付けたシャフトをめっき槽の側壁から外部に突出する構造であっても、パーティクルの発生を確実に防止することができる。
【００５１】
また本発明によれば、基板を基板ホルダに保持したまま、めっき処理とめっきの前処理及び／又はめっきの後処理とを行うことができ、めっき装置と前処理装置及び／又は後処理装置を別々に設ける必要がなく、装置の小型化が図れるばかりか、コストダウンが図れる。
【図面の簡単な説明】
【図１】本発明の一実施の形態にかかるめっき装置１の概略構成図である。
【図２】図２（ａ）は切り欠き溝１１の部分をめっき槽１０の外側から見た要部側面図、図２（ｂ）は図２（ａ）の平面図、図２（ｃ）は液流れ防止体１５を取り外した状態を示す要部側面図である。
【図３】シャフト６１がめっき槽１０の側壁から外部に突出した部分近傍を示す要部拡大断面図である。
【図４】めっき装置１を備えためっき処理機構３００の概略平面図である。
【図５】本発明の他の実施の形態にかかるめっき装置１−２の概略構成図である。
【符号の説明】
１めっき装置
Ｗ基板
Ｗ１被めっき処理面
Ｑめっき液
１０めっき槽
１１切り欠き溝
１４ガイド溝
１５液流れ防止体
１７凹部
２０オーバーフロー槽
３０アノードホルダ
３１アノード
４０中間マスク
４１中央孔
５０パドル
６０基板ホルダ
６１シャフト
６３カップリング
６５めっき液飛び散り防止部材
７０回転駆動手段
８０めっき液循環手段
８１，８３，８７配管
８５リザーバタンク
Ｐ循環ポンプ
８９恒温ユニット
９１フィルタ
９５揺動手段
１００隙間
２００洗浄装置（基板処理装置）
２０１処理液供給手段
２０２カップ
２０３処理液収納凹部
２０５ドレン管
３００めっき処理機構
３１０基板搬送装置
３１１レール
３１３基板搬送ロボット
３１５アーム
３３０カセットテーブル
３５０アライナ
３７０スピンドライヤ
１−２めっき装置
３１−２アノード
８８ノズル[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plating method and a plating apparatus for plating a surface to be plated of a substrate, and particularly to forming a plating film in fine wiring grooves and holes provided in a surface to be plated such as a semiconductor wafer or a resist opening. Also, the present invention relates to a plating method and a plating apparatus for forming a bump (protruding electrode) for electrically connecting a semiconductor chip and a substrate on a surface to be plated of a semiconductor wafer.
[0002]
[Prior art]
Conventionally, for example, in a TAB (Tape Automated Bonding) or a flip chip, gold, copper, solder, nickel, or a protruding layer formed by laminating these at a predetermined position (electrode) on the surface of a semiconductor chip on which wiring is formed. 2. Description of the Related Art It is widely practiced to form a connection electrode (bump) and electrically connect to a substrate electrode or a TAB electrode via the bump. As a method for forming the bump, there are various methods such as an electrolytic plating method, a vapor deposition method, a printing method, and a ball bump method. However, with the increase in the number of I / Os and the fine pitch of the semiconductor chip, miniaturization is possible. Electroplating methods, which have relatively stable performance, have come to be used frequently.
[0003]
Here, the electrolytic plating method is a jet type or cup type in which the surface to be plated of a substrate such as a semiconductor wafer is placed horizontally with the surface to be plated facing downward (face down), and a plating solution is blown up from below to perform plating. The substrate is set up vertically, and a plating solution is injected from below the plating tank and overflowed while the substrate is immersed in the plating solution to perform plating. In the electroplating method employing the dip method, plating is performed by setting the substrate vertically so that air bubbles generated on the surface of the substrate to be plated can be easily removed and the plating on the surface of the substrate to be plated This is to make it difficult for particles and the like to adhere to the surface. According to the electroplating method in which the substrate is vertically erected to perform plating, bubbles caused by a vigorous reduction reaction when performing high-speed plating can be easily removed, and thus it is suitable for high-speed plating.
[0004]
By the way, in the above-mentioned electrolytic plating apparatus employing the conventional dip method, a substrate holder for holding a substrate such as a semiconductor wafer in a detachable manner by sealing an outer peripheral end surface and a rear surface thereof, exposing a surface (a surface to be plated), and exposing the substrate. The substrate holder is immersed in a plating solution together with the substrate to perform plating on the surface to be plated of the substrate.
[0005]
However, in the electroplating method employing the above-mentioned conventional dip method, the substrate is immersed in the plating solution in the plating tank in a vertically standing state, and the plating solution is directed upward from the bottom of the plating tank. Since the plating solution flows, the injected plating solution is always supplied from the lower portion to the upper portion of the surface to be plated of the substrate, so that the unevenness in the flow rate of the plating solution occurs between the upper portion and the lower portion of the surface of the substrate to be plated. There is a problem that plating conditions are slightly different between an upper portion and a lower portion of the surface to be plated of the substrate, and a slight difference occurs in the thickness of the plating depending on the location of the surface to be plated of the substrate. Also, the unevenness of the current density has caused the non-uniformity of the plating.
[0006]
[Patent Document 1]
JP-A-2002-363797
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and an object of the present invention is to improve the uniformity of the plating film thickness by eliminating the unevenness in the flow rate of the plating solution and the unevenness in the current density which cause the non-uniformity of the plating. It is another object of the present invention to provide a highly reliable substrate plating method and apparatus capable of performing high-speed plating.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 of the present application is directed to a plating method for electrolytically or electrolessly plating a surface of a substrate to be plated by immersing the substrate in a plating solution. And electroless plating while rotating in a vertical position. Plating is performed with the surface of the substrate to be plated upright, so that bubbles adhering to the surface to be plated can be immediately eliminated, and bubbles due to a vigorous reduction reaction during high-speed plating can be easily removed. Speeding up of plating. At the same time, the plating is performed while rotating the substrate, so that there is no chipping or plating omission, uniformity of the plating film can be achieved, and a high quality plating film can be obtained.
[0009]
The invention according to claim 2 of the present application is directed to a plating method in which a substrate to be plated is subjected to electrolytic or electroless plating by immersing the substrate in a plating solution in a plating tank. A plating method characterized by preventing the generation of particles due to contact and the generation of crystals of the plating solution by making the portion of the attached shaft projecting outside from the side wall of the plating tank out of contact with the side wall of the plating tank. is there.
Since the shaft and the side wall of the plating tank are not in contact with each other, a sealing structure is not required and the structure can be simplified, and crystals of the plating solution are not generated by flowing the plating solution through the gap between the side wall of the plating tank and the shaft. Further, since there is no sliding portion, no particles are generated and contamination of the plating solution can be prevented.
[0010]
The invention according to claim 3 of the present application is the plating method according to claim 2, wherein the plating solution leaked from a gap generated due to non-contact between the side wall of the plating tank and the shaft is circulated in the plating tank. This is a characteristic plating method. Thereby, the plating solution leaked from the gap between the side wall of the plating tank and the shaft can be circulated, and can be effectively used.
[0011]
The invention according to claim 4 of the present application is the plating method according to claim 2 or 3, wherein the plating solution overflows from the plating tank and the overflowing plating solution is circulated to the plating tank. Is the way. By overflowing the plating solution, a large amount of the plating solution can be supplied to the surface to be plated of the substrate, and the plating can be speeded up.
[0012]
The invention according to claim 5 of the present application is directed to a plating apparatus that performs electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank. A plating apparatus comprising: a rotation driving unit that rotates with a surface to be plated standing upright. Plating is performed with the surface of the substrate to be plated upright, so that bubbles adhering to the surface to be plated can be immediately eliminated, and bubbles due to a vigorous reduction reaction during high-speed plating can be easily removed. Speeding up of plating. At the same time, since the rotation drive means for rotating the substrate is provided, plating can be performed while rotating the substrate, and there is no chipping or missing of plating, uniformity of the plating film can be achieved, and a high quality plating film can be obtained.
[0013]
The invention according to claim 6 of the present application is directed to a plating apparatus that performs electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank. A plating apparatus characterized in that a shaft of a substrate holder, which holds the surface to be plated in a vertical state, protrudes outside from a side wall of a plating tank in a non-contact state with the side wall of the plating tank. Since the shaft and the side wall of the plating tank do not contact each other, a sealing structure is not required and the structure can be simplified, and the plating solution leaks from a gap generated by the non-contact between the side wall of the plating tank and the shaft, thereby preventing the plating solution from flowing. The flow causes a plating solution crystal to not be formed in this portion, and further, since there is no sliding portion, no particles are generated, and contamination of the plating solution can be prevented.
[0014]
The invention according to claim 7 of the present application is the plating apparatus according to claim 6, wherein the plating solution circulating means for circulating the plating solution leaked from the gap between the side wall of the plating tank and the shaft into the plating tank. It is a plating apparatus characterized by being provided. Thereby, the plating solution leaked from the gap between the side wall of the plating tank and the shaft can be circulated, and can be effectively used.
[0015]
The invention according to claim 8 of the present application is the plating apparatus according to claim 6, wherein the shaft is provided with a rotation driving unit that rotationally drives the shaft and the substrate holder outside the plating tank. It is a plating apparatus. Thereby, the substrate holder and the substrate immersed in the plating solution can be easily rotated.
[0016]
The invention according to claim 9 of the present application is the plating apparatus according to claim 6, wherein the plating tank is provided with a notch groove for raising the shaft, and covers an upper portion of the shaft inserted into the notch groove. A plating apparatus characterized in that a liquid flow prevention body is detachably attached. This makes it easy to attach and detach the shaft to and from the plating tank.
[0017]
The invention according to claim 10 of the present application is the plating apparatus according to claim 6, wherein a portion of the shaft protruding outside from a side wall of the plating tank leaks from a gap between the side wall of the plating tank and the shaft. A plating apparatus comprising a plating solution scattering prevention member for preventing a plating solution from scattering due to rotation of a shaft. This can effectively prevent the plating solution from scattering.
[0018]
The invention according to claim 11 of the present application is the plating apparatus according to claim 6, wherein the substrate holder and the shaft are moved to a position where the surface of the substrate holder holding the substrate is pulled up from the plating solution and becomes horizontal. A plating apparatus comprising a swinging means for swinging. This facilitates both attachment and detachment of the substrate to and from the substrate holder and insertion of the substrate holder with the substrate into the plating bath.
[0019]
The invention according to claim 12 of the present application is directed to a plating apparatus for performing electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank. A substrate plating position in which the substrate held in the substrate holder is immersed in a plating solution by swinging a shaft attached to the substrate holder, and a substrate processing position in which the substrate held in the substrate holder is pre-processed and / or post-processed. And a oscillating means for moving the substrate and a substrate processing apparatus for pre-processing and / or post-processing the substrate near the substrate holder moved to the substrate processing position. Thus, plating processing and pre-processing and / or post-processing can be performed while holding the substrate in the substrate holder, and there is no need to separately provide a plating apparatus and a pre-processing apparatus and / or a post-processing apparatus. Not only can this be achieved, but also costs can be reduced.
[0020]
The invention according to claim 13 of the present application is the plating apparatus according to claim 12, wherein the substrate plating position is a position where the substrate to be plated is immersed in a plating solution with the surface to be plated standing upright. Wherein the substrate processing position is a position where the surface to be plated of the substrate is pulled up from the plating solution and is horizontal.
[0021]
The invention according to claim 14 of the present application is the plating apparatus according to claim 12 or 13, wherein a rotation driving unit that rotates the shaft and the substrate holder is attached to the shaft. It is a plating apparatus that performs.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a plating apparatus 1 according to one embodiment of the present invention. As shown in FIG. 1, the plating apparatus 1 has an overflow tank 20 surrounding the outer periphery of the plating tank 10, and has an anode 31 held by an anode holder 30 and a substrate holder 60 inside the plating tank 10. The substrate W is installed facing the substrate W, the intermediate mask 40 and the paddle 50 are installed between the installed anode 31 and the substrate W, and a shaft 61 attached to the substrate holder 60 is driven to rotate outside the overflow tank 20. And a plating solution circulating means 80 for circulating the plating solution Q in the plating tank 10. Hereinafter, each component will be described.
[0023]
The plating tank 10 is formed in a box shape having an open upper surface, and is configured such that the plating solution Q stored in the plating tank 10 overflows from the upper end side of the plating tank 10.
[0024]
The anode 31 has a disk shape and is held by the anode holder 30 so as to be vertically set in the plating solution Q. Further, the intermediate mask 40 is provided with a central hole 41 corresponding to the size of the substrate W, so that the potential of the peripheral portion of the substrate W is lowered and the thickness of the plating film is equalized in each portion of the substrate W. A current required for electrolytic plating flows between the anode 31 and the substrate W.
[0025]
The paddle (stirring bar) 50 reciprocates in parallel with the plating surface W1 of the substrate W (in FIG. 1, moves parallel to the front of the drawing in FIG. 1), thereby plating along the plating surface of the substrate W. The flow of the solution Q is made more uniform over the entire surface to be plated to form a plating film having a more uniform film thickness over the entire surface to be plated.
[0026]
The surface to be plated W1 exposed to the outside of the substrate W held by the substrate holder 60 is installed in the plating solution Q so as to be upright (vertically). A shaft 61 protrudes from the surface of the substrate holder 60 opposite to the surface holding the substrate W, penetrates through the side wall of the plating bath 10 and the side wall of the overflow bath 20 and protrudes to the outside. 70 is connected to a rotating shaft 71. At a portion where the shaft 61 penetrates the side wall of the plating tank 10, a notch groove 11 is provided from an upper end side of the side wall to a portion penetrating the shaft 61, and a notch groove 11 is formed on an outer surface of the notch groove 11. A liquid flow prevention member 15 for blocking the upper part of the shaft 61 inserted in the upper part is detachably attached in the up-down direction. Here, FIG. 2A is a side view of a main part of the notch groove 11 as viewed from the outside of the plating tank 10 (a view as viewed from the direction of arrow A in FIG. 3; however, the illustration of the plating solution scattering prevention member 65 is omitted). 2 (b) is a plan view of FIG. 2 (a), and FIG. 2 (c) is a side view of an essential part showing a state in which the liquid flow preventing body 15 is removed. As shown in the figure, the notch groove 11 is formed to have a width slightly larger than the diameter of the shaft 61, and the lower end portion of the notch groove 11 is formed in a semicircular shape having an inner diameter slightly larger than the diameter of the shaft 61. Thus, the shaft 61 can be pulled up without contacting the inner periphery of the cutout groove 11. Guide grooves 14 extending vertically are provided on both sides of the notch groove 11 so as to be able to move up and down while guiding both sides of the liquid flow prevention body 15. The liquid flow prevention body 15 is formed of a rectangular flat plate, and a semicircular recess 17 having an inner diameter slightly larger than the diameter of the shaft 61 is provided in the center of the lower side. Then, as shown in FIG. 2A, when the shaft 61 is inserted into the notch groove 11 and the liquid flow preventing member 15 is attached, the inside of the circular opening formed by the lower end portion of the notch groove 11 and the concave portion 17 is formed. At this time, a circular gap 100 is formed around the shaft 61, and the shaft 61 and the side wall of the plating tank 10 and the liquid flow preventing body 15 do not come into contact with each other.
[0027]
Returning to FIG. 1, a plating solution scattering prevention member 65 is fixed to a portion of the shaft 61 protruding outside from the side wall of the plating tank 10. FIG. 3 is an enlarged sectional view of a main part showing the vicinity of a portion where the shaft 61 protrudes outside from the side wall of the plating tank 10. In the figure, the plating solution scattering prevention member 65 is a substantially disk-shaped plate body, and the plating solution Q leaking from the gap 100 is bent by the outer peripheral edge thereof being bent toward the side wall side of the plating tank 10 so that the shaft solution is removed. So that it does not scatter around due to the centrifugal force caused by the rotation of.
[0028]
Notch grooves 21 extending from the upper end side of the side wall of the overflow tank 20 to the part penetrating the shaft 61 are also provided in the portion where the shaft 61 penetrates the side wall of the overflow tank 20. The notch groove 21 is formed to have a width slightly larger than the diameter of the shaft 61, so that the shaft 61 is cut not only when the shaft 61 is installed in the notch groove 21 but also when the shaft 61 is pulled upward. It is configured so as not to contact the inner periphery of the notch 21.
[0029]
As described above, the rotation shaft 71 of the rotation driving means 70 is fixed to the tip of the shaft 61 protruding outside the overflow tank 20 so as to rotate integrally with the shaft 61 by the coupling 63. The rotation driving means 70 is constituted by an electric motor, and rotationally drives the shaft 61 and the substrate holder 60 at a predetermined number of rotations. Further, the rotation driving means 70 includes a swinging means 95 for swinging the substrate holder 60 and the shaft 61 upward about the axis a1. That is, the oscillating means 95 is positioned at the position indicated by the solid line in FIG. 1 around the rotation driving means 70 itself (axis a1), that is, the plating target surface W1 of the substrate W held by the substrate holder 60 is vertically moved in the plating solution Q. The substrate holder 60 and the shaft 61 are swung from a substrate plating position perpendicular to the substrate processing position to a position indicated by a two-dot chain line in FIG. I do.
[0030]
Note that a cleaning apparatus (substrate processing apparatus) 200 is installed above the substrate holder 60 that has moved to the substrate processing position. The cleaning apparatus 200 has a processing liquid supply means (cleaning liquid supply means) 201 provided with a cup 202 for preventing scattering of the cleaning liquid, a ring-shaped processing liquid storage recess 203 provided on a lower side of the outer periphery of the cup 202, and a processing liquid storage means. A drain tube 205 is connected to a predetermined position of the recess 203.
[0031]
The plating solution circulating means 80 connects the bottom surface of the overflow tank 20 and the reservoir tank 85 with a pipe 81, and also connects the maximum water level of the plating solution Q in the overflow tank 20 with the reservoir tank 85 with a pipe 83. The bottom of 10 and the reservoir tank 85 are connected by a pipe 87, and a circulation pump P, a constant temperature unit 89, and a filter 91 are attached to the pipe 87. The pipe 81 collects the plating solution Q overflowing into the overflow tank 20 in the reservoir tank 85, the pipe 83 prevents the level of the plating solution Q in the overflow tank 20 from rising above the maximum water level, and the pipe 87 uses the circulation pump P Thus, the plating solution Q in the reservoir tank 85 is supplied from the bottom of the plating tank 10.
[0032]
Next, a step of performing a plating process on the plating target surface W1 of the substrate W using the plating apparatus 1 will be described. There are various types of plating, and for example, copper plating, nickel plating, solder plating, and further, gold plating can be used in the same manner. First, the substrate holder 60 and the shaft 61 are set in the plating tank 10 as shown by a solid line in FIG. At this time, the surface W1 to be plated of the substrate W held by the substrate holder 60 is in an upright state in the plating tank 10. Then, by driving the circulation pump P, the plating solution Q in the reservoir tank 85 is adjusted to a temperature suitable for plating by the constant temperature unit 89, and further supplied to the plating tank 10 after particles and the like are removed by the filter 91. The plating solution Q supplied into the plating tank 10 circulates through the plating tank 10, overflows from the upper end side of the plating tank 10, and moves to the overflow tank 20. The plating solution Q collected in the overflow tank 20 is collected in a reservoir tank 85 by a pipe 81. Note that the water level of the plating solution Q in the overflow tank 20 is prevented from rising above its maximum water level position by a pipe 83.
[0033]
On the other hand, a part of the plating solution Q in the plating tank 10 leaks into the overflow tank 20 from a gap 100 (see FIG. 2A) formed at a portion where the shaft 61 protrudes from the side wall of the plating tank 10.
[0034]
Then, the paddle 50 is reciprocally moved in parallel with the plating surface W1 of the substrate W (moves in the front-rear direction in FIG. 1), so that the flow of the plating solution Q along the plating surface W1 of the substrate W is covered. The substrate holder 60 and the substrate W are rotated (for example, 50 rotations / minute) by the rotation driving means 70 while making the entire surface of the plating processing surface W1 more uniform, and at the same time, electricity is supplied between the anode 31 and the substrate W. Electroplating is performed on the plating target surface W1. At this time, since the surface W1 to be plated of the substrate W immersed in the plating solution Q is in an upright state, bubbles that adversely affect the quality of plating are well removed. Therefore, bubbles can be easily removed by a vigorous reduction reaction when performing high-speed plating, and plating can be performed at high speed and highly reliable plating can be performed. By the way, when the plating solution Q is flowed upward from below the plating tank 10 while the substrate W is set up and down in the plating tank 10 as described above, the plating solution Q is always subjected to the plating treatment of the substrate W. Since the liquid is supplied from the lower part of the surface W1 to the upper part, the flow velocity unevenness occurs in each part of the surface W1 to be plated of the substrate W, and the plating conditions are different between the upper part and the lower part of the surface W1 to be plated of the substrate W. There is a possibility that the plating film thickness is slightly different depending on the location of the plating target surface W1 (the plating thickness at the lower portion of the plating target surface W1 is larger than the plating thickness at the upper portion. It will be thicker). In addition, the current density (electric field distribution) of each part of the surface W1 to be plated of the substrate W may be uneven. However, in the present embodiment, since the substrate W is rotated during the plating of the substrate W, the upper part and the lower part of the surface W1 to be plated of the substrate W are sequentially switched, whereby the plating of the surface W1 to be plated of the substrate W is performed. The conditions (flow rate of plating solution and current density) are the same, and the film thickness of plating becomes uniform. The rotation speed of the substrate W varies depending on the type of plating, the size of the substrate W, the characteristics of the plating solution Q, and the like, but is generally preferably 0 to 500 (rotation / minute), and more preferably 0 to 200 (rotation / minute). And more preferably 0 to 100 (rotation / minute).
[0035]
In the present embodiment, the shaft 61 penetrates the side wall of the plating tank 10 and protrudes to the outside. However, if the shaft 61 of the side wall of the plating tank 10 protrudes to the outside, the shaft 61 is sealed. If the plating solution Q inside is prevented from leaking, the following problems occur. That is, first, since the shaft 61 rotates, it is difficult to seal, and the sealing structure becomes complicated. Further, even if the sealing is performed, the plating solution Q stays in a narrow gap generated in the sealed portion, and crystals of the plating solution Q are generated. Further, the rotation of the shaft 61 generates particles due to sliding with the sealing portion, and may contaminate the plating solution Q. Therefore, in the present embodiment, the gap 100 is provided by keeping the portion where the shaft 61 penetrates the side wall of the plating tank 10 out of contact, thereby eliminating the need for a sealing structure (in other words, leaking a small amount of the plating solution Q to reduce the fluid resistance). Simplification of the structure, flowing of the plating solution Q through the gap 100 prevents the formation of crystals of the plating solution Q, and eliminates sliding parts so that particles are not generated and the plating solution Q They tried to prevent contamination. Then, the plating solution Q is discharged from the gap 100. The plating solution Q is collected in the overflow tank 20 and circulated to the plating tank 10 by the plating solution circulating means 80. The plating solution Q discharged from the gap 100 tends to fly around when the shaft 61 rotates, but since the plating solution splash prevention member 65 is fixed to the shaft 61, the plating solution Q is prevented from scattering. You.
[0036]
A cutout groove 21 is provided on the side wall of the overflow tank 20, but the plating solution Q accumulated in the overflow tank 20 does not rise above the position where the pipe 83 is connected (the highest water level of the plating solution Q). Therefore, it does not reach the notch groove 21. In addition, since the shaft 61 does not touch the side wall of the overflow tank 20, particles are not generated at this portion and the plating solution Q is not contaminated.
[0037]
When the plating process on the substrate W is completed as described above, the energization between the anode 31 and the substrate W is stopped to terminate the electrolytic plating, and the plating solution Q in the plating tank 10 is kept at a predetermined low water level. The liquid holder 15 is pulled upward by a drive mechanism (not shown), and the rocking means 95 is driven to rock the substrate holder 60 and the shaft 61 upward. Move to the substrate processing position indicated by. During the movement, the shaft 61 passes through the notched grooves 11 and 21 having a width larger than the diameter of the shaft 61, so that the shaft 61 does not touch them and no particles are generated.
[0038]
The cleaning device 200 descends from the upper part of the substrate holder 60 moved to the substrate processing position, as shown by a two-dot chain line, covers the periphery of the substrate holder 60 with the cup 202, and performs processing while rotating the substrate holder 60 in this state. Cleaning is performed by spraying and supplying a cleaning liquid (for example, pure water) from the liquid supply unit 201 to the plating target surface W1 of the substrate W. The cleaning liquid after cleaning the plating target surface W1 is drained from the processing liquid storage recess 203 on the outer periphery of the cup 202 through the drain pipe 205. When the cleaning is completed, the cleaning apparatus 200 moves up, the substrate transport robot 313 described below takes out the substrate W held in the substrate holder 60, and mounts the next unprocessed substrate W on the substrate holder 60. Then, the substrate holder 60 and the shaft 61 are pivoted downward about the rotation driving means 70 to move the substrate holder 60 to the substrate plating position shown by the solid line in FIG. After the mounting, the plating process is performed in the same process as described above.
[0039]
By the way, in the plating apparatus 1, if the chemical liquid supplied by the processing liquid supply means 201 is a chemical liquid for pre-processing, the cleaning apparatus 200 can be changed to a substrate pre-processing apparatus. If the processing liquid supplied by the processing liquid supply unit 201 is a plurality of types of cleaning liquids and other types of chemical liquids, a single processing liquid supply unit 201 can perform a plurality of types of processing. For example, first, pre-processing is performed on the plating target surface W1 of the unprocessed substrate W at the substrate processing position of the plating apparatus 1, then plating is performed at the substrate plating position, and cleaning processing or the like is performed again at the substrate processing position. Post-processing can be performed. That is, the cleaning apparatus 200 can be configured as a substrate processing apparatus that performs pre-processing and post-processing.
[0040]
FIG. 4 is a schematic plan view of a plating mechanism 300 having the plating apparatus 1. As shown in the figure, the plating processing mechanism 300 has a total of six plating apparatuses 1 installed on each of the three right and left sides of the substrate transport apparatus 310, and houses the substrate W near one end of the substrate transport apparatus 310. Three cassette tables 330 for mounting cassettes, an aligner 350 for aligning the orientation flats and notches of the substrate W in a predetermined direction, and a spin drier 370 for rotating the substrate W after plating at a high speed and drying it. It is configured. The substrate transfer device 310 is configured such that a substrate transfer robot 313 moves on a rail 311, and the substrate transfer robot 313 moves a substrate W between the various devices by an arm 315.
[0041]
A series of electroplating processes performed by the plating mechanism 300 configured as described above will be described. First, one substrate W is taken out from the cassette mounted on the cassette table 330 by the substrate transfer robot 313, and is placed on the aligner 350, and the orientation flat, the notch, etc. To the predetermined direction. Next, the substrate W whose direction has been adjusted by the aligner 350 is transferred by the substrate transfer robot 313 to any one of the plating apparatuses 1 for which the plating process has been completed. Then, the plating apparatus 1 to which the substrate W has been transported performs the plating process (including the pretreatment and the cleaning process) on the substrate W by the above-described method. Next, the substrate W that has been subjected to the pretreatment, the plating treatment, and the cleaning treatment in the plating apparatus 1 is transferred to the spin dryer 370 by the substrate transfer robot 313 and spin-dried (drained) by the high-speed rotation of the spin dryer 370. The substrate is transferred to the cassette of the cassette table 330 by the substrate transfer robot 313. It goes without saying that the number and arrangement position of the plating apparatus 1 and other apparatuses can be arbitrarily changed.
[0042]
It goes without saying that the metal to be plated by each plating apparatus 1 can be arbitrarily changed. For example, by changing the metal to be plated by each plating apparatus 1, nickel plating, copper plating, and solder plating are sequentially performed on the surface of the substrate W, and bumps and the like by multilayer plating composed of nickel-copper-solder are formed by a series of operations. Can be formed. In addition to the Ni-Cu-solder, Cu-Au-solder, Cu-Ni-Solder, Cu-Ni-Au, Cu-Sn, Cu-Pd, and Cu-Ni-Pd-Au , Cu-Ni-Pd, Ni-solder, Ni-Au and the like. The solder may be either a high melting point solder or a eutectic solder. Alternatively, a bump formed by multi-layer plating of Sn-Ag or a bump formed by multi-layer plating of Sn-Ag-Cu may be formed and annealed to form an alloy thereof. Thus, unlike the conventional Sn-Pb solder, it is free of Pb and can solve environmental problems caused by α rays.
[0043]
FIG. 5 is a schematic configuration diagram of a plating apparatus 1-2 according to another embodiment of the present invention. In this figure, the same parts as those of the plating apparatus 1 shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The difference between the plating apparatus 1-2 and the plating apparatus 1 is that an insoluble mesh-shaped anode is used as the anode 31-2, and the end of the pipe 87 on the plating tank 10 side is a back surface of the anode 31-2. And a nozzle 88 is attached to each end of the pipe 87 branched into a plurality of portions, and the plating solution Q supplied into the plating tank 10 by the circulation pump P is supplied from the back side of the anode 31-2 to the anode 31-. This is the point that the injection is performed toward 2. With such a configuration, the plating solution Q can be supplied more uniformly to the plating target surface W1 of the substrate W as compared with the case where the plating solution Q is supplied from the lower surface of the plating tank 10. In addition to the function of rotating the substrate, the in-plane uniformity of the plating film thickness on the surface to be plated W1 of the substrate W can be further enhanced.
[0044]
Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications may be made within the scope of the claims and the technical idea described in the specification and the drawings. It is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and effects of the present invention are exhibited. For example, in the above embodiment, the case where the anode 31 is installed and the electrolytic plating is performed by applying a current between the anode 31 and the substrate W has been described. However, the present invention is also applied to the electroless plating in which the anode 31 and the intermediate mask 40 are not installed. Can be applied.
[0045]
In the above-described embodiment, the substrate holder 60 and the shaft 61 are driven to rotate during plating. However, in some cases, the plating may be performed while the substrate holder 60 and the shaft 61 are stationary. In this case, if the shaft 61 is provided with a bearing on the side wall of the plating tank 10 and the side wall of the overflow tank 20, the shaft 61 does not rotate, so that no particles are generated by sliding rotation. Particles may be generated at the time of attachment / detachment from the side wall, and in order to prevent this, it is effective to make the portion where the shaft 61 penetrates the side wall of the plating tank 10 and the side wall of the overflow tank 20 non-contact. is there.
[0046]
In the above embodiment, the swing means 95 for swinging the substrate holder 60 and the shaft 61 is provided in order to install the substrate W held in the substrate holder 60 in the plating tank 10 or to remove the substrate W from the plating tank 10. By providing a configuration in which the portion of the coupling 63 can be separated without providing the swinging means 95, only the portion of the substrate holder 60 and the shaft 61 is separated from the portion of the coupling 63, and It may be configured to be taken out or to be mounted on the plating tank 10.
[0047]
In the above-described embodiment, the space above the notch groove 11 in which the shaft 61 is inserted is opened and closed by pulling out the liquid flow prevention body 15 in the upward direction. However, the shaft is moved by moving the liquid flow prevention body 15 in the horizontal direction. The space above the notch groove 11 in which the 61 is inserted may be opened and closed.
[0048]
Further, in the above-described embodiment, the shaft W attached to the substrate holder 60 holding the substrate W protrudes outside from the side wall of the plating tank 10, and the substrate W is rotated by attaching the rotation driving unit 70 to the protruded shaft 61. The structure for rotating the substrate W may be any of various other structures. In other words, any structure can be used as long as the surface to be plated W1 of the substrate W immersed in the plating solution Q can be rotated in the upright state. The rotation driving means having such a structure may be used.
[0049]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to eliminate unevenness in flow velocity and current density of a plating solution which causes non-uniformity of plating, uniformity of plating film thickness is improved, and high-speed plating is performed. It becomes possible to do.
[0050]
Further, according to the present invention, generation of particles can be reliably prevented even in a structure in which a shaft attached to a substrate holder for holding a substrate projects outside from a side wall of a plating tank.
[0051]
Further, according to the present invention, it is possible to perform plating and pre-treatment of plating and / or post-treatment of plating while holding the substrate in the substrate holder, so that the plating apparatus and the pre-processing apparatus and / or the post-processing apparatus can be used. It is not necessary to provide them separately, so that not only the size of the device can be reduced, but also the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a plating apparatus 1 according to an embodiment of the present invention.
2 (a) is a side view of a main part of a cutout groove 11 viewed from outside a plating tank 10, FIG. 2 (b) is a plan view of FIG. 2 (a), and FIG. 2 (c). FIG. 4 is a side view of a main part showing a state where a liquid flow prevention body 15 is removed.
FIG. 3 is an enlarged sectional view of a main part showing the vicinity of a portion where a shaft 61 protrudes outside from a side wall of a plating tank 10.
FIG. 4 is a schematic plan view of a plating mechanism 300 including the plating apparatus 1.
FIG. 5 is a schematic configuration diagram of a plating apparatus 1-2 according to another embodiment of the present invention.
[Explanation of symbols]
1 Plating equipment
W substrate
W1 Plated surface
Q Plating solution
10 Plating tank
11 Notch groove
14 Guide groove
15 Liquid flow prevention body
17 recess
20 overflow tank
30 Anode holder
31 Anode
40 Intermediate mask
41 Central hole
50 paddles
60 substrate holder
61 shaft
63 coupling
65 Plating solution scattering prevention member
70 Rotation driving means
80 Plating solution circulation means
81, 83, 87 piping
85 reservoir tank
P circulation pump
89 constant temperature unit
91 Filter
95 Rocking means
100 gap
200 Cleaning equipment (substrate processing equipment)
201 Processing liquid supply means
202 cups
203 Processing liquid storage recess
205 drain tube
300 plating mechanism
310 substrate transfer device
311 rail
313 Substrate transfer robot
315 arm
330 cassette table
350 Aligner
370 Spin dryer
1-2 Plating equipment
31-2 Anode
88 nozzles

Claims

In a plating method of electrolytically or electrolessly plating the surface to be plated of the substrate by immersing the substrate in a plating solution,
A plating method characterized by performing electrolytic or electroless plating while rotating a substrate to be plated of a substrate immersed in a plating solution while standing upside down.

In a plating method of subjecting a surface to be plated of a substrate to electrolytic or electroless plating by immersing the substrate in a plating solution of a plating tank,
By making the portion of the shaft attached to the substrate holder holding the substrate protruding outside from the side wall of the plating tank out of contact with the side wall of the plating tank, generation of particles due to contact and generation of crystals of the plating solution are prevented. A plating method characterized in that:

The plating method according to claim 2, wherein
A plating method characterized by circulating a plating solution leaked from a gap generated by a non-contact between a side wall of a plating tank and a shaft in the plating tank.

The plating method according to claim 2 or 3, wherein
A plating method, wherein a plating solution overflows from a plating tank and the overflowing plating solution is circulated to the plating tank.

In a plating apparatus that performs electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank,
A plating apparatus, comprising: a rotation drive unit that rotates with a surface to be plated of a substrate immersed in a plating solution standing upright.

In a plating apparatus that performs electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank,
A plating characterized in that a shaft of a substrate holder for holding a substrate immersed in a plating solution with its surface to be plated standing upright is projected outside from a side wall of a plating tank in a non-contact state with the side wall. apparatus.

The plating apparatus according to claim 6,
A plating solution circulating means for circulating a plating solution leaked from a gap between a side wall of the plating tank and a shaft into the plating tank;

The plating apparatus according to claim 6,
A plating apparatus, wherein the shaft is provided with a rotation driving means for rotating and driving the shaft and the substrate holder outside the plating tank.

The plating apparatus according to claim 6,
A plating apparatus, wherein a notch groove for raising the shaft is provided in the plating tank, and a liquid flow prevention member for blocking an upper portion of the shaft inserted into the notch groove is detachably attached.

The plating apparatus according to claim 6,
A portion of the shaft protruding outward from the side wall of the plating bath is provided with a plating solution scattering prevention member for preventing a plating solution leaking from a gap between the side wall of the plating bath and the shaft from scattering due to rotation of the shaft. Plating equipment.

The plating apparatus according to claim 6,
A plating apparatus, further comprising a swinging means for swinging the substrate holder and the shaft until the surface of the substrate holder holding the substrate is pulled up from the plating solution and becomes horizontal.

In a plating apparatus that performs electrolytic or electroless plating of a surface to be plated of a substrate by immersing the substrate in a plating solution of a plating tank,
By rocking the substrate holder holding the substrate and the shaft attached to the substrate holder, a substrate plating position where the substrate held in the substrate holder is immersed in a plating solution, and the substrate held in the substrate holder is subjected to pretreatment and Swing means for moving to a substrate processing position for post-processing is provided, and a substrate processing apparatus for performing pre-processing and / or post-processing of the substrate is installed near the substrate holder moved to the substrate processing position. And plating equipment.

The plating apparatus according to claim 12, wherein
The substrate plating position is a position where the substrate to be plated is immersed in a plating solution with the surface to be plated standing upright,
The substrate processing position is a position where the surface to be plated of the substrate is pulled up from the plating solution and is horizontal.

The plating apparatus according to claim 12 or 13,
A plating apparatus, wherein a rotation drive unit for rotating the shaft and the substrate holder is attached to the shaft.