200406875 玖、發明說明： 【發明所屬之技術領域】 本發明係關於接合晶片或晶圓、各種電路基板等的在基 材表面具有金屬接合部的被接合物彼此間的接合方法及裝 置。 【先前技術】 作為接合具有金屬接合部的被接合物彼此間的接合方 法，迄今以來已知有利用超音波的接合方法。但是，習知 之超音波接合中，若形成於接合面的表面的氧化膜及有機 物層、污染層為較厚層者、或為牢固黏接者時，要藉由施 加超音波充分破壞或除去此等有相當的困難，事實上無法 進行可靠度高的超音波接合。另外，在此種狀況下，若要 強制接合，而提高超音波的強度（例如，增大振幅）、或長 時間施加時，會對作為被接合物的晶片及形成於此的凸塊 造成損傷，從而使得接合製品的可靠度大幅下降。另外， 長時間的施加將招致接合的生產節拍時間增加，而並不理 想。因此，在習知之方法中，超音波的強度增大及施加時 間的增加為困難而並不理想者，若因為如此而若維持低強 度、短時間施加的話，便無法進行可靠度高的超音波接合。 另一方面，與上述超音波接合不同，作為接合具有接合 部的被接合物彼此間的接合方法，日本特許第2 7 9 1 4 2 9號 公報揭示有在接合矽晶圓的接合'面彼此間時，接合前先在 溫室的真空中照射惰性氣體離子束或惰性氣體高速原子束 以進行濺射蝕刻的矽晶圓的接合方法。該接合方法中，在 312/發明說明書(補件)92-12/921263 09 200406875 砍晶圓的接合面上 飛散，並以被活性 由原子間的高結合 可不需要接合用的 接觸，即可以常溫 但是，該接合方 在真空中，必須在 此，從藉由上述電 保持指定的真空狀 一部分構成於可保 密封機構變得規模 價。另外，為了分 驟，若將此等在不 持指定的真空狀態 被接合物搬送至接 得困難，同時，會 方法中，因為未進 而獲得良好的接合 力，因此可能對半 物半導體造成損傷 關於藉由如上述 洗淨而予以接合的 如上述的接合面的 且，在大氣中進行 的氧化物或有機物等 化的原子形成表面， 力而接合。因此，在 加熱，而僅僅使被活 或接近此的低溫進行 法中，被姓刻的接合 維持表面活性化的狀 子束的表面洗淨至接 態，尤其是必須將接 持為指定的真空度的 大，造成裝置全體的 別依上述電子束的表 同的處所進行，則需 ，或在保持該真空的 合處所的機構，不僅 招致裝置全體的大型 行高溫加熱，因此為 面積，有必要施加3 0 導體電路上的類似凸 〇 的依電子束照射的濺 方法，最近，開始探 表面活性化的對於接 被接合物的金屬接合 將因上述電子束而 其表面彼此間係藉 該方法中，基本上 性化的表面彼此間 接合。 面彼此間的接合， 態下才能進行。因 合為止，必須始終 合用的機構的至少 處理室内，因此其 大型化、且變得高 面洗淨與接合的步 要在兩個處所間保 狀態下從洗淨處將 實際的裝置設計變 化。另外，本接合 擊潰接合面的凹凸 0 MPa程度的高加壓 塊及光元件的化合 射蝕刻進行表面 究最大限度確保依 合的有利點，並 部彼此間的接合的 312/發明說明書(補件)92-12/92126309 6 200406875 可行性。若表面活性化後，可在大氣中進行接合的 在真空中等進行接合的情況比較，可大幅簡略化接 及裝置。 【發明内容】 在此，本發明等考慮到前述習知存在的超音波接 題點，著重於最近所開始檢討的依如上述的表面活 接合技術，經過刻意檢討、試驗的結果，藉由很好 入上述兩技術及加熱，發現可解決上述習知超音波 問題點，從而完成可以習知之銲接熔點以下的溫度 屬接合的本發明。 也就是說，本發明之目的在於，提供一種利用超 接合方法及裝置，其可使超音波的強度降低及施加 短，可進行不會對被接合物及接合部造成損傷的所 音波接合，同時，接合的生產節拍時間也可縮短， 可減低接合所要求的超音波能的容量，以使裝置全 型化、成本降低成為可能。另外，提供一種接合方 置，其即使在依接合面的表面活性化的低溫接合， 加超音波，仍可以無對凸塊等造成損傷之虞的低加 行接合。 為了達成上述目的，本發明之接合方法，其特徵 將具有金屬接合部的被接合物彼此間接合於基材的 時，藉由能量波洗淨兩被接合物的上述金屬接合部 後，在大氣中以超音波接合金屬接合部彼此間。金 部的表面的藉由能量波的洗淨，可在大氣壓下進行 312/發明說明書(補件)92-12/921263 09 話，與 合步驟 合的問 性化的 地組合 接合的 進行金 音波的 時間縮 需的超 並且， 體的小 法及裝 藉由施 壓力進 為：在 表面上 的表面 屬接合 ，也可 7 200406875 在減壓條件下進行。 接合用的超音波施加條件，為了可抑制對金屬接合部的 損傷（尤其是裂縫的產生），最好為如下的較佳條件。也就 是說，設定施加之超音波的振幅未滿3 // m。較好為2 // m 以下。最好為1 μ m以下。 另外，因減小如上述的超音波的振幅以使施加超音波強 度降低而引起的接合性能的降低，可利用提高所施加的超 音波的頻率來彌補。作為超音波的頻率較好為40kHz以 上，最好為60kHz以上。 另外，及由施加超音波，與依習知的表面活性化的低溫 下的加壓接合比較，可大幅降低接合荷重。為了抑制對金 屬接合部的損傷而達成良好的接合，最好將接合荷重設定 為150MPa以下。 作為金屬接合部的表面洗淨用的能量波，最好為電漿， 其中，最好為在氬氣環境下的電漿。 上述接合可在常溫下進行，但是因為藉由加熱的一併利 用，可助長顆粒的擴散，因此，更為容易擊潰接合界面的 凹凸而達成平坦化，從而可獲得良好的接合狀態。作為加 熱溫度較好為1 8 0 °C以下，而最好為1 5 0 °C以下。也就是 說，因為習知一般的低溫金屬接合係為銲接接合，其銲接 熔點在1 8 3 °C的程度，因此，本發明可進行較此還低溫的 接合，亦即，可進行1 8 0 °C以下而最好為1 5 0 °C以下的接合。 在依上述能量波的洗淨中，在金屬接合部的被接合的全 表面最好蝕刻1 n m以上的深度。藉由可蝕刻如此之深度以 8 312/發明說明書(補件)92-12/92126309 200406875 上的能量波照射，可獲得在大氣中接合金屬接合部彼此間 所需要的表面性狀態。 本發明之超音波接合，尤其是為接合表面由Au、Cu、Al、 I η、S η的任一者所組成的金屬接合部彼此間的情況為佳。 例如，作為相互接合的金屬接合部的組合，可為Au、Cu、 A 1、I η、S η的任一的同種金屬彼此間、或任意的2個異種 金屬彼此間、或一方為Au而另一方為Cu、Al、In、Sn的 任一者的組合。其中，在Au彼此間的組合情況，常溫下也 可確實接合。但是，即便在A u彼此間的接合以外的情況（例 如，A u / C u、A u / A 1等的接合等），仍可在常溫或接近此的 低溫下進行接合。另外，在由特定的金屬、例如由Au來組 成至少一邊的金屬接合部的情況，可由Au來構成形成金 屬接合部的電極等的全體，但也可由Au來僅僅構成表面。 由Au來構成表面用的形態並無特別的限定，可採用藉由濺 鍍或蒸鍍等來形成鍍金的形態或Au薄膜的形態。另外，若 將接合表面限定於Au，藉由表面活性化，使得即使在大氣 中仍可以常溫進行接合，在依常溫接合的接合基礎上，即 便藉由施加超音波減去約一半的加壓力，仍可擊潰界面的 凹凸而獲得良好的接合。習知，需要3 0 0 Μ P a程度的加壓 力，但是，表面活性化後藉由施加超音波，可降低為約 1 5 0 Μ P a 程度。 上述金屬接合部彼此間的接合時，最好將金屬接合部間 的間隙變動設定在最大4 // m以下。若間隙變動設為4 // m 以下，以適宜的接合荷重、例如3 0 0 Μ P a程度（最好為 9 312/發明說明書(補件)92-12/92126309 200406875 1 5 0 Μ P a以下）的接合荷重，可抑制在金屬接合部彼此間的 接合所需要的間隙變動以下。另外，金屬接合部彼此間的 接合時，最好將被接合物間的平行度調整在4 // m以内。藉 由如此之平行度調整，可較小地抑制上述間隙變動，同時， 可由金屬接合部彼此間進行密接的面接觸，可更為容易進 行低溫接合。 另外，金屬接合部彼此間的接合時，最好將至少一邊的 金屬接合部的接合前的表面粗糙度（尤其是表面的起伏）設 定在3 0 0 n m以下，以便使表面彼此間能良好密接。藉由設 定如此之表面粗糙度，可進行更為密接地接合。 最好將金屬接合部的接合後的表面粗糙度設定在1 0 n m 以下。藉由將接合後的界面壓潰為表面粗糙度1 0 n m以下， 使得接合面積增大，而可成為低電阻且分配強度也良好的 接合。 另外，以上述相同的目的，將至少一邊的金屬接合部的 表面硬度設定在維氏硬度H v 1 2 0以下，最好係藉由退火將 硬度降低為1 0 0以下。例如，表面硬度Η ν最好為3 0〜7 0 的範圍内（例如，平均Η ν為5 0 )。利用設為如此之低硬度， 於施加接合荷重時適當使金屬接合部的表面變形，而可更 為密接地接合。 本發明之接合裝置，係為將具有金屬接合部的被接合物 彼此間接合於基材的表面的裝置，其特徵為：具備洗淨機 構，係將能量波照射於各被接合物的上述金屬接合部的表 面；及接合機構，在大氣中以超音波接合從上述機構取出 10 312/發明說明書(補件)92-12/921263 09 200406875 的被接合物的金屬接合部彼此間。在該接合裝置中，也可 將上述洗淨機構形成於在大氣壓下將能量波照射於金屬接 合部的表面的機構上，也可形成為在減壓條件下將能量波 照射於金屬接合部的表面的機構。 為了將接合用的超音波施加條件設為最佳條件，上述接 合機構，為了減少損傷，最好為可施加振幅未滿3 // m、較 好為2 // m以下，而最好為1 // m以下的超音波的機構。另 外，接合機構藉由構成為可施加頻率為4 0 k Η z以上，最好 為6 0 k Η ζ以上的超音波的機構，而可減小振幅而增加能 量，因此此構成較為理想。又，接合機構最好構成為可以 1 5 OMPa以下的接合荷重進行接合的機構。 在該接合裝置中，上述洗淨機構最好由電漿照射機構所 組成，其中，最好為由氬氣電漿照射機構所構成。 上述接合機構具有加熱機構，最好構成為以較銲接熔點 低的1 8 0 °C以下而最好為1 5 0 °C以下的溫度而可超音波接 合金屬接合部彼此間的機構。 上述洗淨機構，為進行在大氣中接合金屬接合部彼此間 所需要的表面蝕刻，最好構成為可在金屬接合部的被接合 的全表面餘刻1 n m以上的深度的能量以上照射能量波的機 構。 另外，被接合之兩金屬接合部的表面金屬種的組合，如 上述，可為A u、C u、A 1、I η、S η的任一的同種金屬彼此間、 或任意的2個異種金屬彼此間、或一方為Au而另一方為 C u、A 1、I η、S η的任一者的組合。其中，在A u彼此間的 11 312/發明說明書(補件)92-12/921263 09 200406875 組合的情況，接合最為容易。 另外，上述接合機構最好具備將金屬接合部彼此間的接 合時的間隙的變動設定在最大4 // m以下的機構。另外，上 述接合機構最好具備將金屬接合部彼此間的接合時的被接 合物間的平行度調整在4 // m以内的機構。另外，最好將至 少一邊的金屬接合部的接合前的表面粗糙度設定在3 0 0 n m 以下。另外，最好將至少一邊的金屬接合部的接合後的表 面粗糙度設定在1 0 n m以下。又，將至少一邊的金屬接合部 的表面硬度設定在維氏硬度H v 1 2 0以下，最好為1 0 0以下。 本發明還提供藉由上述接合方法所製作的接合體。也就 是說，本發明之接合體，係為在基材的表面具有金屬接合 部的被接合物彼此間的接合體，其特徵為：藉由能量波洗 淨兩被接合物的上述金屬接合部的表面後，在大氣中藉由 超音波接合金屬接合部彼此間來製成。 上述接合體中，可由半導體來構成被接合之被接合物的 至少一邊的被接合物。 在如上述的本發明之接合方法及裝置中，在減壓條件下 或大氣壓下將能量波照射於被接合物的金屬接合部的表 面，在大氣中超音波接合藉由餘刻洗淨表面而被活性化的 金屬接合部彼此間。因為事先藉由能量波照射除去表面的 氧化膜、有機物層、污染層，因此，可以低強度的超音波 在短時間内進行所需的接合。據此，可進行不會施加損傷 於被接合物或接合部的良好的超音波接合，同時，超音波 接合所需時間短，接合步驟全體的生產節拍時間亦可縮 12 312/發明說明書(補件)92-12/921263 09 200406875 短。另外，因為超音波施加機構的容量也小，因此可達成 裝置全體的小型化、低成本化。又，因為可在大氣中進行 接合，因此用於接合的大規模的真空裝置及其所需要的密 封裝置等變得沒有必要，從該點看，也可大幅簡略步驟全 體、裝置全體，而可使成本降低。另外，因為可在低溫或 接近此的溫度進行接合，因此用於加熱之裝置負擔也減小。 因為事先藉由能量波照射除去表面的氧化膜、有機物 層、污染層，因此，可進行習知所無法進行的異種金屬彼 此間的接合，例如，可進行金/銅或金/紹的超音波接合， 可大幅擴大超音波接备的適用範圍。 另外，因為是在依事先的能量波照射的接合面的表面活 性化後，藉由施加超音波的接合，即使在常溫接合，仍可 大幅減低接合荷重。接合表面為金的情況，除藉由表面活 性化即便在大氣中也可以常溫進行接合外，在依該常溫接 合之接合中，藉由施加超音波即使降低約一半的加壓力， 仍可擊潰界面的凹凸而形成良好的接合。 又，尤其是本發明中，藉由依事先的能量波照射的洗淨 與超音波接合的組合，以大幅緩和接合條件。在習知之超 音波接合中，必須要施加振幅為3 // in以上的超音波^但是 在振幅為3 // m以上進行接合雖可大大增加接合性，但也有 造成損傷之虞。本發明中，藉由依能量波洗淨的接合面的 表面活性化，其污染層變得極薄，因此可降低振幅。因此， 不會因施加超音波而造成損傷（例如，裂縫的產生）。另外， 因振幅降低使得超音波強度也降低，由此雖有降低接合性 13 312/發明說明書(補件)92-12/921263 09 200406875 之虞，但即使因為損傷降低而使振幅降低，但可藉由提高 頻率，尤其是提高頻率為40kHz以上，最好為60kHz以上， 即可充分維持對接合性的貢獻度。總之，因為可以想像接 合機構藉由高頻振動重複進行著金屬本身的膨脹收縮，因 此幾乎不需要增大振幅。 另外，因為藉由施加超音波，增大在接合界面的應力， 因此容易擊潰界面的凹凸，結果可創造出與變柔軟相同的 效果。其結果與僅施加壓力的情況相比較，可以低荷重進 行接合。相對於習知至少需要3 0 0 Μ P a的接合荷重，只要 1 5 0 Μ P a以下的接合荷重即可。 又，藉由進行在適宜溫度下的加熱的併用、對金屬接合 部的間隙變動的抑制、平行度的調整等，可更^容易地進 行指定的超音波接合。 如此，根據本發明之接合方法及裝置，可進行不會被施 加損傷之所需超音波接合，亦可達成超音波接合時間的縮 短、進而達成接合步驟全體的生產節拍時間的縮短，同時， 可縮小超音波能容量，因此可實現裝置全體的小型化、低 成本。另外，可進行習知所無法進行超音波接合的異種金 屬，例如，金/銅或金/铭的組合的接合。 另外，藉由事先的能量波洗淨，可大幅降低施加超音波 的強度，藉由將施加條件最佳化，即便為易受損傷的被接 合物，仍不會產生損傷，從而可以高生產效率進行良好的 接合。 又，與習知之依表面活性化的低溫接合相比較，藉由施 14 312/發明說明書(補件)92-12/92126309 200406875 加超音波，可大幅減低接合荷重，即便對無法將大的荷重 施加於類似半導體電路上的凸塊或光元件者，仍可進行接 合0 【實施方式】 以下，參照圖式說明本發明之較佳實施形態。 圖1顯示本發明之一實施形態之接合裝置1。在基材的 表面具有金屬接合部2或3的被接合物4或5，首先，在 藉由真空泵6所減壓而為指定的真空度的處理室7内，藉 由從作為依能量波的洗淨機構的電漿照射機構8所照射的 電漿9，藉由蝕刻金屬接合部2或3的表面而被洗淨（洗淨 步驟）。本實施形態中，可為藉由泵1 0在處理室7内供給 氬氣的構成，而可成為在氬氣環境下且在指定的減壓條件 下可照射電漿的構成。又，本實施形態中，係在指定的減 壓條件下照射電漿，但也可在大氣壓下照射電漿。被洗淨 的被接合物4或5係從處理室7内取出，依接合步驟（接合 裝置部1 1 )，金屬接合部2、3彼此間在大氣中進行超音波 接合。 又，上述被接合物4如係由晶片構成，被接合物5如係 由基板構成。但是，在此，晶片係指例如I C晶片、半導體 晶片、光元件、表面安裝零件、晶圓等無關種類及大小而 與基板接合側的全部形態者。在該被接合物4上作為金屬 接合部2形成有如凸塊。另外，基板係指例如樹脂基板、 玻璃基板、薄膜基板、晶片、晶圓等無關種類及大小而與 晶片接合側的全部形態者。作為本發明之具代表性的態 15 312/發明說明書(補件)92-12/92126309 200406875 樣，可舉出被接合之被接合物的至少一者係由半導體所構 成的態樣。 上述被洗淨之被接合物4、5，從具有處理室7的洗淨機 構至接合裝置部1 1的接合機構，係以適當的搬送機構進行 搬送。在接合裝置部1 1，例如在指定的待機部1 2載置有 上述被洗淨之被接合物4、5。被接合物4係於反轉機構1 3 的頭部1 4，以不觸及洗淨面的方式藉由吸附等予以保持， 在上下反轉後，以金屬接合部2面向下的形態藉由吸附等 保持在設於搭接頭1 5下部的搭接具1 6上。被接合物5係 從待機部1 2進行移載，例如，以金屬接合部3面向上的形 態藉由吸附等保持在搭接台1 7上。本實施形態中，搭接具 16内建有作為加熱機構的加熱器18，成為在大氣中、在常 溫下的接合、加熱下的接合的任一情況均可接合的構成。 搭接頭1 5係形成為可控制介由搭接具1 6，將被接合物 4向下方頂壓，對被接合物5施加指定的接合荷重的狀態。 本實施形態中，搭接頭1 5係形成為可上下方向（Z方向）移 動及位置定位的狀態。於該搭接頭1 5或搭接具1 6設有超 音波施加機構1 9，本實施形態中，藉由施加超音波振動於 被接合物4側、尤其是其金屬接合部2，即可在與被接合 物5的金屬接合部3之間進行超音波接合。 另外，保持上述被接合物5的搭接台1 7，在本實施形態 中，係形成為藉由依設於下部的位置調整台2 0的X、Y方 向的水平方向位置控制、0方向的旋轉方向位置控制、及 X軸、Y軸周圍的傾斜調整控制，可進行與被接合物4之間 16 312/發明說明書(補件)92-12/921263 09 200406875 的相對位置定位及平行度調整的構成，成為可將 部彼此間的接合時的間隙變動抑制在最小限度的 相對位置定位及平行度調整，係藉由可進退插入 物4、5之間的認識機構、例如2視野的認識機構 2視野照相機），讀取附設於被接合物4、5或此 機構的認識標記（省略圖示），基於所讀取的資訊 行位置或角度的必要修正來實施。2視野的認識米 可進行X、Y方向的位置調整，根據情況也可進行 位置調整。該相對位置定位及平行度調整，在本 中，只要是在搭接台1 7側進行，但也可在搭接耳 接具1 6側進行，也可在兩側進行。在兩側進行的 據必要在搭接頭1 5側不只進行升降控制，還可進 制及/或平行移動控制，而在搭接台1 7側也可進 制、平行移動控制及升降控制，此等控制形態根 作任意的組合。 使用如上述的接合裝置，依如下動作實施本發 方法。首先，在成為指定的真空度的處理室7内 電漿洗淨作為被接合物4的晶片4的金屬接合部 凸塊），及作為被接合物5的基板5的金屬接合部 電極），將表面活性化。在電漿洗淨中，為進行超 而充分除去表面異物層以使表面活性化，因此最 接合部的被接合全表面以可钮刻1 n m以上的方式 漿照射強度、時間。若以一例表示，為由1 0 0 V、 漿洗淨機構照射5秒鐘的Ar電漿的水準。 312/發明說明書(補件)92-12/921263 09 金屬接合 構成。該 於被接合 2 1 (例如， 等的保持 ，藉由進 I構21係 Z方向的 實施形態 員1 5或搭 情況，根 行旋轉控 行旋轉控 據必要可 明之接合 ，由 A r 2 (例如， 3 (例如， 音波接合 好在金屬 來設定電 5 0W的電 17 200406875 被表面洗淨之晶片4及基板5，暫時放置於待機部1 2， 晶片4被上下反轉後保持於搭接具1 6上，而基板5未被反 轉地保持於搭接台1 7上。對向保持之晶片4及基板5，係 基於由2視野的認識機構2 1所讀取的資訊，以進入指定的 精度内的方式進行位置對準，以平行度也進入指定的精度 内的方式進行調整。尤其是關於平行度，為達成良好的超 音波接合，最好將兩被接合物間的平行度設為4 v m以下， 並且，調整金屬接合部間的間隙的變動最大為4 // m以下。 從該狀態降下搭接具1 6，施加指定的接合荷重，根據必 要藉由加熱器1 8進行加熱，利用藉由超音波施加機構1 9 所施加的超音波振動，在大氣中超音波接合晶片4的金屬 接合部2 (凸塊）及基板5的金屬接合部3。 在習知之超音波接合中，如上所述，若接合面表面的氧 化膜及有機物層、污染層為較厚層、或為.牢固黏接時，事 實上無法進行超音波接合。但是，在如上述的本發明之超 音波接合中，在接合前施加能量波，本實施形態中施加依 Ar電漿的表面洗淨，於接合面表面施以超音波接合所必要 的餘刻，充分除去如上述的異物層或使被分解的表面充分 活性化，因此，可以較習知低的超音波施加強度（例如，較 習知小的振幅），且以較習知短的時間進行所需的超音波接 合。因此，不需要為用於接合而勉強地提高超音波施加強 度或增加施加時間，還可除去施加損傷於晶片及凸塊之 虞，從而可確保接合品質。另外，因為可縮短超音波接合 時間，也可縮短接合步驟全體的生產節拍時間，可大幅提 18 312/發明說明書(補件)92-12/92126309 200406875 升生產效率。又，因為超音波施加強度可小，因而可縮小 超音波能量容量，可使超音波施加機構1 9小型化及廉價。 因此，可實現裝置全體的小型化及低成本化。 在該超音波接合中，如上所述，若將至少一邊的金屬接 合部的接合前的表面粗糙度設定在3 0 0 n m以下，或是，將 至少一邊的金屬接合部的接合後的表面粗糙度設定在 1 0 n m以下，或是，將至少一邊的金屬接合部的表面硬度設 定在維氏硬度H v 1 2 0以下，或是，接合時併用加熱的手段 側相當有效。藉由加熱可降低表面的硬度，或使接合時之 表面上的原子的移動活性化，從而可更為容易進行所需的 超音波接合。 尤其是藉由加熱的併用的效果很大，期可獲得依加熱的 效果與依能量波洗淨的效果兩方的相乘效果。尤其是加熱 至1 5 0 °C時，可獲得極大的效果。尤其是以較習知的銲接 熔點低的溫度進行接合，與習知的銲接接合相比較維持低 溫接合的特徵，可發揮依能量波洗淨的效果。但是，加熱 溫度可以在不會對裝置產生過大的負擔的方式，且不會因 加熱而於金屬接合部產生不利的方式，適當設定為例如 1 8 0 °C以下，最好為1 5 0 °C以下的溫度（例如，如上述，為 1 5 0 °C附近的溫度或其以下的溫度）。 另外，本發明之在能量波洗淨後在大氣中進行超音波接 合的方法中，如後述之實施例所示，尤其是金屬接合部的 表面均由Au組成的情況，可以較低的超音波施加強度、較 短的施加時間進行所需的超音波接合。但是，本發明之接 19 312/發明說明書(補件)92_ 12/92126309 200406875 合方法中，為於事先進行能量波洗淨，並不限於A u / A u接 合，可進行上述各種金屬的任意組合，例如，可成為A u / C u 或A u / A 1的超音波接合，若如上述併用加熱的手段，有關 此等異種金屬彼此間的超音波接合也可更為容易地進行。 為確認如上述的本發明的作用、效果，在進行A u / A u的 金屬接合部的超音波接合時，針對無事先的電漿洗淨而進 行超音波接合的情況，與有進行電漿洗淨後進行超音波接 合的情況，還加上加熱之效果確認，進行了試驗。電漿洗 淨係進行1次可蝕刻作為金屬接合部的凸塊表面1 n m的深 度的能量處理。作為一例，以1 0 0 V、5 0 W的電漿機構進行 5秒鐘的A r電漿洗淨。評價係於接合體重複加上-6 5 °C〜 + 1 5 0 °C間的溫度變動，進行測定針對此時的凸塊接合的良 品率（％)的熱衝擊試驗。其結果可獲得圖2所示的特性。 如圖2所示，在無事先的電漿洗淨而依常溫進行超音波 接合的情況，即使在熱衝擊週期數少的階段，也只能獲得 低良品率，但是，藉由事先進行電漿洗淨（2次的照射）， 一直到熱衝擊週期數多的階段為止均可獲得高良品率。另 外，為確認加熱的效果，在無事先的電漿洗淨而使接合時 的溫度為1 5 0 °C進行超音波接合時，一直到熱衝擊週期數 多的階段為止均可獲得高良品率。在該圖2所示結果中， 加熱之效果表現得較藉由事先進行電漿洗淨更高，但是， 這是因為在1 5 0 °C的較高溫度下進行的試驗，因此可以認 為加熱效果係依賴於溫度，但在較1 5 0 °C低溫的條件下進 行試驗的情況，也有出現事先電漿洗淨的效果較高的情 20 312/發明說明書(補件)92-12/92126309 200406875 況。在進行事先電漿洗淨與加熱兩方的情況，進行1次電 漿洗淨的情況與進行2次電漿洗淨的情況的雙方，均可獲 得極高的效果，因此可以知道上述二者之併用為最佳形態。 另外，在進行A u / A u接合的情況，與習知之僅僅進行超 音波接合的情況比較，為了確認在本發明之進行事先電漿 洗淨時，可降低超音波的施加強度的情況，進行求得施加 超音波的振幅（// m)與接合品的分布強度（g /凸塊）的關係 的模型試驗。結果如圖3所 的超音波施加為對象，尤其 果，而使用在現在普通使用 者。在該模型試驗的條件中 振幅的超音波比較，本發明 加超音波降低為4 // m，仍可 以確認事先電漿洗淨可對施 的作用。可減小超音波的振 傷也減少，另外，作為超音 價者，而可貢獻裝置全體的 接合所必要的超音波能量也 時間也可縮短，可縮短接合 合步驟全體的生產節拍時間 Au彼此間的情況，表面不存 況，即使不以減壓電漿強制 漿機構的氧氣電漿將有機物 接合。 示，該模型試驗係以較大振幅 是為了確認事先電漿洗淨的效 的晶片上形成較大型的凸塊 ，與習知之施加1 0 # in程度的 之方法中，可確認到即便將施 獲得相同的接合強度，因而可 加超音波強度的降低貢獻較大 幅，即意味著晶片及凸塊的損 波施加機構也可成為小型且廉 小型化、低成本。另外，可知 可為較小，因而，超音波施加 所需要的時間，進而可貢獻接 的縮短。又，在金屬接合部為 在氧化而僅為有機物。該情 進行蝕刻，亦可利用大氣壓電 除去，仍可進行其後的超音波 21 312/發明說明書(補件)92-12/921263 09 200406875 又，隨著近年來的急速發展，金屬接合部（凸塊）的間隙 極小的被微細間距化的晶片、亦即習知為進行超音波接合 有必要施加3 // m以上的振幅的超音波，藉由本發明之方法 可進行上述相同的模型試驗。針對試驗結果，圖4顯示與 接合品的分布強度（g /凸塊）的關係。藉由進行事先電漿洗 淨，可知以未滿3 // m的超音波振幅可獲得優良的效果。 即，在3 // m的振幅時，在凸塊内進入有微小的裂縫，但在 2 // m的振幅時，則完全未進入有裂縫。另外，在1 // m的 振幅也可進行接合。 另外，在該模型試驗中，圖5顯示測定在不施加超音波 於凸塊（材質：A u、硬度：6 0 H v、初期表面粗糙度：3 0 0 n m ) 的情況的凸塊的崩潰量與接合荷重的結果。如圖5所示， 在習知之常溫結合中，為達成良好的接合（凸塊崩潰量：1 μ m以上、接合後的表面粗糙度：1 0 n m以下），需要施加 3 0 0 Μ P a的接合荷重，但是利用施加超音波，以一半的 1 5 0 Μ P a的接合荷重即可獲得相同的效果。 又，圖6顯示本發明之方法之振幅1 // m之超音波施加 時之接合後的良品率與施加超音波的頻率的關係。如圖6 所示，利用頻率為4 0 k Η z以上，尤其是6 0 k Η z以上，即便 為振幅1 // Π1之超音波’仍可獲得極為優良的效果。 如此，尤其是通過上述的模型試驗可知，在習知之超音 波接合中，需要有3 0 0 MPa或此以上的接合荷重，但在本發 明之方法中，可成功以1 50MPa的接合荷重進行接合。 (產業上之可利用性） 22 312/發明說明書(補件)92-12/92126309 200406875 本發明之接合裝置及方法，可適用具有金屬接合部的被 接合物彼此間的任何超音波接合，尤其是適合於至少一邊 的被接合物為半導體的情況的超音波接合。 【圖式簡單說明】 圖1為本發明之一實施形態之接合裝置的概略構成圖。 圖2為熱衝擊試驗週期與良品率的關係圖。 圖3為模型試驗之超音波振幅與分布強度的關係圖。 圖4為另一模型試驗之超音波振幅與分布強度（相對值） 的關係圖。 圖5為模型試驗之接合荷重與凸塊崩潰量的關係圖。 圖6為振幅1 // m之超音波施加試驗之頻率與良品率（相 對值）的關係圖。 (元件符號說明） 1 接合裝置 2 金屬接合部 3 金屬接合部 4 被接合物（晶片） 5 被接合物（基板） 6 真空泵 7 處理室 8 電漿照射機構 9 電漿 10 A r氣體供給泵 11 接合裝置部 23 312/發明說明書(補件)92-12/92126309 200406875 12 待 機 部 13 反 轉 機 構 14 反 轉 機 構 的 頭 部 15 搭 接 頭 16 搭 接 具 17 搭 接 台 18 作 為 加 熱 機 構 的加熱器 19 超 音 波 施 加 機 構 20 位 置 調 整 台 21 2 視 野 的 認 識 機構 312/發明說明書(補件)92-12/92126309200406875 (ii) Description of the invention: [Technical field to which the invention belongs] The present invention relates to a method and a device for bonding wafers, wafers, various circuit substrates, and the like to be bonded with a metal bonded portion on a surface of a substrate. [Prior Art] Conventionally, a bonding method using ultrasonic waves has been known as a bonding method for bonding objects to be bonded having metal bonding portions. However, in the conventional ultrasonic bonding, if the oxide film and the organic layer, the contaminated layer formed on the surface of the bonding surface are thicker, or the adhesive layer is firmly adhered, it must be sufficiently destroyed or removed by applying ultrasonic waves. There are considerable difficulties, and in fact, highly reliable ultrasonic bonding cannot be performed. In addition, in such a situation, if the bonding is forced, and the intensity of the ultrasonic wave is increased (for example, the amplitude is increased), or if it is applied for a long time, the wafer as the bonded object and the bump formed thereon will be damaged. Therefore, the reliability of the joined product is greatly reduced. In addition, prolonged application will result in increased joint production cycle times, which is undesirable. Therefore, in the conventional method, it is not ideal to increase the intensity of the ultrasonic wave and increase the application time. If this is the case, if it is maintained at a low intensity and applied for a short time, a highly reliable ultrasonic wave cannot be performed. Join. On the other hand, unlike the above-mentioned ultrasonic bonding, Japanese Patent No. 2 7 9 1 4 2 9 discloses a bonding method of bonding silicon substrates to each other as a bonding method for bonding objects to be bonded having a bonding portion. At the same time, a method of bonding a silicon wafer by irradiating an inert gas ion beam or an inert gas high-speed atomic beam in a vacuum in a greenhouse to perform sputter etching before bonding. In this bonding method, 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875 scatters the bonding surface of the diced wafer, and is activated by the high bonding between atoms. The bonding contact is not required, that is, normal temperature can be used. However, the joining side is in a vacuum, and it is necessary here that a portion of the vacuum state specified by the above-mentioned electric holding is constituted in the sealable mechanism, and the scale becomes expensive. In addition, in order to step, if it is difficult to transport these objects to the joint without holding the specified vacuum state, at the same time, because the method does not further obtain a good bonding force, it may cause damage to the semi-conductor semiconductor. The atoms on the joint surface as described above that are joined by washing as described above and equalized by oxides or organic substances in the atmosphere form a surface and are joined by force. Therefore, in the low temperature process in which heating is performed only to be activated or close to this, the surface of the bundle of state-knotted bonds maintained by surface bonding is washed to the connected state, and in particular, the specified vacuum must be maintained. The larger the size of the entire device, which is different from the above-mentioned electron beam, needs to be maintained, or the mechanism of the combined space that maintains the vacuum, not only causes the large rows of the entire device to be heated at high temperature, so for the area, it is necessary to apply The electron beam irradiation method similar to convex 0 on a conductor circuit. Recently, the surface activation of a metal bond to an object to be joined will be caused by the above-mentioned electron beam. The substantially textured surfaces are bonded to each other. The joining of the faces can only be performed in a state. Since it is necessary to always use at least the processing room of a common mechanism, the size of the structure must be increased, and the steps of washing and joining must be changed from the washing place to the actual equipment design. In addition, this joint breaks the unevenness of the joint surface with a high-pressure block of about 0 MPa and the combined radio-etching of the optical element is performed on the surface to ensure the favorable points of compliance to the maximum. ) 92-12 / 92126309 6 200406875 feasibility. When the surface is activated, the bonding can be performed in the atmosphere, and the bonding can be greatly simplified compared to the case where the bonding is performed in a vacuum or the like. [Summary of the Invention] Here, the present invention and the like take into account the conventional ultrasonic problems, and focus on the surface living bonding technology as described above, which has been recently reviewed. Taking into account the above two technologies and heating, it was found that the conventional ultrasonic problems can be solved, and the present invention which can be joined at a temperature below the conventional welding melting point is completed. That is, it is an object of the present invention to provide a method and a device for using super-bonding, which can reduce the strength and short application of ultrasonic waves, and can perform sono-wave bonding without damaging the bonded object and the joint, and at the same time, In addition, the production cycle time of the joint can be shortened, and the capacity of the ultrasonic energy required for the joint can be reduced, so that the device can be made full and the cost can be reduced. In addition, there is provided a bonding method capable of performing low-pressure bonding without causing damage to bumps or the like even when ultrasonic bonding is performed at a low-temperature bonding activated by the surface of the bonding surface. In order to achieve the above object, the joining method of the present invention is characterized in that when joining objects having metal joints to each other to a base material, the metal joints of the two joints are washed by energy waves, and then are exposed to the atmosphere. The medium-to-sonic ultrasonic bonding metal joints are between each other. The surface of the gold part can be cleaned by energy waves and can be performed at atmospheric pressure 312 / Invention Specification (Supplement) 92-12 / 921263 09. The golden sound waves can be combined in a combination with a step-by-step solution. The time reduction required is more than that, and the method and installation of the body are performed by applying pressure: the surface on the surface is joined, and it can also be performed under reduced pressure. The conditions for applying ultrasonic waves for joining are preferably the following conditions in order to prevent damage to the metal joint (especially the occurrence of cracks). That is, the amplitude of the applied ultrasonic wave is set to be less than 3 // m. It is preferably 2 // m or less. It is preferably 1 μm or less. In addition, the decrease in the bonding performance caused by reducing the amplitude of the ultrasonic waves as described above to reduce the intensity of the applied ultrasonic waves can be compensated by increasing the frequency of the applied ultrasonic waves. The frequency of the ultrasonic wave is preferably 40 kHz or more, and more preferably 60 kHz or more. In addition, the application of ultrasonic waves can significantly reduce the bonding load compared with conventional low-temperature pressure bonding with surface activation. In order to suppress damage to the metal joint and achieve a good joint, it is preferable to set the joint load to 150 MPa or less. The energy wave for cleaning the surface of the metal joint is preferably a plasma, and particularly, a plasma in an argon atmosphere. The above-mentioned bonding can be performed at normal temperature. However, the combined use of heating can promote the diffusion of particles. Therefore, it is easier to break the unevenness of the bonding interface to achieve flattening, and a good bonding state can be obtained. The heating temperature is preferably 180 ° C or lower, and more preferably 150 ° C or lower. That is, since the conventional low-temperature metal bonding system is a welding joint, and its welding melting point is about 1 3 3 ° C, the present invention can perform a lower temperature bonding, that is, 1 8 0 Joints below 150 ° C and preferably below 150 ° C. In the cleaning by the energy wave described above, it is preferable that the entire surface of the metal joint portion to be joined is etched to a depth of 1 n m or more. By irradiating such a depth with the energy wave at 8 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875, it is possible to obtain a surface state required for joining metal joints to each other in the atmosphere. The ultrasonic bonding of the present invention is particularly preferably a case where metal bonding portions whose bonding surfaces consist of any one of Au, Cu, Al, I η, and S η are between each other. For example, as a combination of mutually joined metal joints, any one of Au, Cu, A 1, I η, and S η may be the same type of metal, or any two different types of metal may be one of Au, The other is a combination of any one of Cu, Al, In, and Sn. Among them, when Au is combined with each other, it can be surely joined at normal temperature. However, even in the case where Au is not bonded to each other (for example, bonding of Au / Cu, Au / A1, etc.), bonding can be performed at normal temperature or a low temperature close to this. In addition, in the case where a metal junction including at least one side is made of a specific metal, for example, Au, the entire electrode or the like forming the metal junction may be formed by Au, but only the surface may be formed by Au. The form of the surface made of Au is not particularly limited, and a gold-plated form or an Au thin film form can be adopted by sputtering, vapor deposition, or the like. In addition, if the bonding surface is limited to Au and the surface is activated, the bonding can be performed at normal temperature even in the atmosphere. On the basis of the bonding at normal temperature, even if the ultrasonic pressure is reduced by about half, The unevenness of the interface can still be crushed to obtain a good joint. Conventionally, a pressure of about 300 MPa is required. However, after surface activation, ultrasonic waves can be applied to reduce the pressure to about 150 MPa. When joining the metal joints to each other, it is preferable to set the gap variation between the metal joints to a maximum of 4 // m or less. If the gap variation is set to 4 // m or less, with a suitable joining load, for example, about 3 0 0 Μ P a (preferably 9 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875 1 5 0 Μ P a The joining load below) can suppress the fluctuation of the gap required for joining between the metal joining portions. In addition, when joining metal joints, it is best to adjust the parallelism between the objects to be joined within 4 // m. By adjusting the parallelism in this way, the above-mentioned gap variation can be suppressed to a small extent. At the same time, the metal joints can be brought into close surface contact with each other, and low-temperature bonding can be performed more easily. In addition, when joining metal joints, it is preferable to set the surface roughness (especially the surface undulations) of the metal joints on at least one side before joining to 300 nm or less, so that the surfaces can adhere to each other well. . By setting such a surface roughness, more dense bonding can be performed. It is desirable to set the surface roughness after joining of the metal joint to 10 n m or less. By crushing the interface after bonding to a surface roughness of 10 nm or less, the bonding area is increased, and a low-resistance and good distribution strength bond can be obtained. In addition, for the same purpose as described above, the surface hardness of the metal joint portion on at least one side is set to be less than Vickers hardness H v 120, and it is preferable to reduce the hardness to 100 or less by annealing. For example, the surface hardness Η ν is preferably in the range of 30 to 70 (for example, the average Η ν is 50). With such a low hardness, the surface of the metal joint portion is appropriately deformed when a bonding load is applied, and the bonding can be performed more closely. The bonding device of the present invention is a device for bonding objects to be joined having metal joints to the surface of a base material, and is characterized in that it includes a cleaning mechanism and irradiates energy waves onto the metals of each object to be joined. The surface of the joint; and a joint mechanism that ultrasonically joins the metal joints of the object to be joined 10 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875 to each other by ultrasonic bonding in the atmosphere. In this bonding apparatus, the above-mentioned cleaning mechanism may be formed on a mechanism that irradiates an energy wave on the surface of the metal bonding portion under atmospheric pressure, or may be formed to irradiate the energy wave on the metal bonding portion under reduced pressure. Surface body. In order to optimize the application conditions of the ultrasonic wave for joining, it is preferable that the joining mechanism has an amplitude of less than 3 // m, preferably 2 // m or less, and more preferably 1 in order to reduce damage. // Ultrasonic mechanism below m. In addition, since the joining mechanism is configured to be capable of applying an ultrasonic wave having a frequency of 40 k Η z or more, and preferably 60 k Η ζ or more, it can reduce the amplitude and increase the energy, so this configuration is preferable. The joining mechanism is preferably configured as a mechanism capable of joining at a joining load of 15 OMPa or less. In this bonding apparatus, it is preferable that the cleaning mechanism is composed of a plasma irradiation mechanism, and among them, an argon plasma irradiation mechanism is preferable. The above-mentioned joining mechanism has a heating mechanism, and is preferably constituted as a mechanism capable of ultrasonically joining metal joining portions with each other at a temperature of 180 ° C or lower, and more preferably 150 ° C or lower, which is lower than the welding melting point. The above-mentioned cleaning mechanism is preferably configured to irradiate energy waves at a depth of 1 nm or more on the entire surface of the metal joint to be joined in order to perform surface etching required to join the metal joints in the atmosphere. Agency. In addition, as described above, the combination of the surface metal species of the two metal joints to be joined may be any one of the same metals of Au, Cu, A1, Iη, and Sη, or any two different species. The metals, or a combination of Au, and Cu, A 1, I η, and S η on one side or the other side. Among them, in the case of the combination of 11 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875 between Au, the joining is the easiest. In addition, it is preferable that the above-mentioned joining mechanism includes a mechanism for setting a variation in a gap at the time of joining metal joining portions to a maximum of 4 // m or less. In addition, it is preferable that the above-mentioned joining mechanism includes a mechanism for adjusting the parallelism between the to-be-joined materials when the metal joining portions are joined to each other within 4 // m. In addition, it is preferable to set the surface roughness before joining of at least one metal joint to 300 nm or less. In addition, it is preferable to set the surface roughness after joining of the metal joining portion on at least one side to 10 nm or less. In addition, the surface hardness of the metal joint portion on at least one side is set to a Vickers hardness H v 12 or less, preferably 100 or less. The present invention also provides a bonded body produced by the above bonding method. That is, the bonded body of the present invention is a bonded body between objects to be joined having metal joints on the surface of the substrate, and is characterized in that the metal joints of the two joints are cleaned by energy waves. After the surface is formed, the metal joints are ultrasonically bonded to each other in the atmosphere. In the above-mentioned bonded body, a semiconductor can be used to form a bonded object on at least one side of the bonded object. In the bonding method and device of the present invention as described above, the surface of the metal bonding portion of the object to be bonded is irradiated with energy waves under reduced pressure or atmospheric pressure, and the ultrasonic bonding is performed by washing the surface in the atmosphere. Activated metal joints are between each other. Since the surface oxide film, organic layer, and contaminated layer are removed by irradiation with energy waves in advance, low-intensity ultrasonic waves can be used to perform the required bonding in a short time. As a result, it is possible to perform a good ultrasonic bonding without applying damage to the object or the joint. At the same time, the ultrasonic bonding time is short, and the production cycle time of the entire bonding step can be shortened by 12 312 / Invention Specification (Supplementary Pieces) 92-12 / 921263 09 200406875 short. In addition, since the capacity of the ultrasonic application mechanism is also small, the size and cost of the entire device can be reduced. In addition, since bonding can be performed in the atmosphere, a large-scale vacuum device for bonding and a required sealing device and the like are unnecessary. From this point of view, the entire steps and the entire device can be greatly simplified. Reduce costs. In addition, since bonding can be performed at or near a low temperature, the burden on a device for heating is also reduced. Because the surface oxide film, organic matter layer, and contamination layer are removed by energy wave irradiation in advance, it is possible to bond dissimilar metals that cannot be conventionally known. For example, gold / copper or gold / sauer ultrasound can be performed. Bonding can greatly expand the application range of ultrasonic equipment. In addition, since the surface of the bonding surface irradiated with energy waves beforehand is activated, the bonding by applying ultrasonic waves can significantly reduce the bonding load even at normal temperature bonding. When the bonding surface is gold, in addition to surface activation, the bonding can be performed at normal temperature even in the atmosphere. In bonding at this normal temperature, the interface can be broken even if the applied pressure is reduced by about half by applying ultrasonic waves. The unevenness of the formed good joints. In addition, in the present invention, the combination of washing and ultrasonic bonding by prior energy wave irradiation can significantly reduce the bonding conditions. In the conventional ultrasonic bonding, it is necessary to apply ultrasonic waves with an amplitude of 3 // in or more ^. However, bonding with an amplitude of 3 // m or more can greatly increase the bonding property, but it may cause damage. In the present invention, since the surface of the joint surface cleaned by the energy wave is activated, the contamination layer becomes extremely thin, so that the amplitude can be reduced. Therefore, no damage is caused by the application of ultrasonic waves (for example, the occurrence of cracks). In addition, the ultrasonic intensity is also reduced due to the decrease in amplitude, which may reduce the jointability 13 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875, but even if the amplitude is reduced due to the reduction in damage, it may By increasing the frequency, particularly by increasing the frequency to 40 kHz or more, and preferably 60 kHz or more, the contribution to the bondability can be sufficiently maintained. In short, since it can be imagined that the coupling mechanism repeats the expansion and contraction of the metal itself by high-frequency vibration, there is almost no need to increase the amplitude. In addition, since the stress at the bonding interface is increased by applying an ultrasonic wave, it is easy to break the unevenness of the interface, and as a result, the same effect as that of softening can be created. As a result, compared with a case where only pressure is applied, joining can be performed at a low load. Compared with the conventional need of at least a joint load of 300 MPa, as long as a joint load of 150 MPa or less. In addition, the combination of heating at a suitable temperature, suppression of gap fluctuations in metal joints, adjustment of parallelism, and the like make it possible to more easily perform specified ultrasonic bonding. Thus, according to the bonding method and device of the present invention, it is possible to perform ultrasonic bonding which is not required to be damaged, and to shorten the ultrasonic bonding time, and further shorten the production cycle time of the entire bonding step. Since the ultrasonic energy capacity is reduced, the entire device can be miniaturized and low cost. In addition, it is also possible to perform dissimilar metals such as gold / copper or a combination of gold / inscription which cannot be ultrasonically bonded. In addition, the intensity of the applied ultrasonic waves can be greatly reduced by cleaning the energy wave in advance, and by optimizing the application conditions, even if it is a susceptible to-be-joined object, no damage will occur, and high production efficiency can be achieved. Make good joints. In addition, compared with the conventional low-temperature bonding based on surface activation, by applying 14 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875 and adding ultrasonic waves, the bonding load can be greatly reduced, even if a large load cannot be applied. A bump or an optical element applied to a similar semiconductor circuit can still be bonded. [Embodiment] Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a bonding apparatus 1 according to an embodiment of the present invention. The to-be-joined object 4 or 5 having the metal joints 2 or 3 on the surface of the substrate is firstly subjected to the energy wave in the processing chamber 7 decompressed by the vacuum pump 6 to a predetermined degree of vacuum. The plasma 9 irradiated by the plasma irradiation means 8 of the cleaning mechanism is washed by etching the surface of the metal joint 2 or 3 (cleaning step). In this embodiment, a configuration in which argon gas is supplied by the pump 10 in the processing chamber 7 can be adopted, and a configuration in which plasma can be irradiated under an argon atmosphere and a predetermined reduced pressure condition can be used. In this embodiment, the plasma is irradiated under a predetermined reduced-pressure condition, but the plasma may be irradiated under atmospheric pressure. The cleaned objects 4 or 5 are taken out of the processing chamber 7, and the metal bonding portions 2 and 3 are ultrasonically bonded to each other in the atmosphere according to the bonding step (the bonding device portion 1 1). The object to be bonded 4 is formed of a wafer, and the object 5 is formed of a substrate. Here, the wafer refers to, for example, an IC wafer, a semiconductor wafer, an optical element, a surface-mounted component, a wafer, and the like, all of which are on the substrate-joining side regardless of the type and size. The to-be-joined object 4 is formed as a metal joint 2 as a bump. The substrate refers to, for example, a resin substrate, a glass substrate, a thin-film substrate, a wafer, a wafer, and the like, all of which are bonded to the wafer regardless of the type and size. 15 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875, which is a representative aspect of the present invention, includes a state in which at least one of the joined objects is a semiconductor. The objects to be bonded 4 and 5 to be cleaned are transferred from the cleaning mechanism having the processing chamber 7 to the bonding mechanism of the bonding device section 11 by an appropriate transfer mechanism. The above-mentioned washed objects 4 and 5 are placed on the bonding device section 11 and, for example, a designated standby section 12. The to-be-joined object 4 is attached to the head 14 of the reversing mechanism 1 3 and is held by suction or the like so as not to touch the cleaning surface. After being reversed up and down, the metal joint 2 faces downward and is adsorbed. Wait to be held on the lapping tool 16 provided on the lower part of the lapping joint 15. The to-be-joined object 5 is transferred from the standby portion 12 and is held on the bonding table 17 by suction or the like with the metal joint portion 3 facing upward, for example. In the present embodiment, the bonding tool 16 has a heater 18 built in as a heating mechanism, and has a configuration in which bonding can be performed in the atmosphere, at normal temperature, or under heating. The lap joint 15 is formed to control the state in which the to-be-joined object 4 is pressed downward through the lap joint 16 to apply a specified joining load to the to-be-joined object 5. In this embodiment, the lap joint 15 is formed in a state where it can be moved in the vertical direction (Z direction) and positioned. An ultrasonic wave applying mechanism 19 is provided on the lap joint 15 or the lap joint 16. In this embodiment, ultrasonic vibration may be applied to the object 4 side, especially the metal joint 2 thereof. Ultrasonic bonding is performed with the metal joint 3 of the object 5. In addition, in the present embodiment, the bonding stage 17 holding the object to be joined 5 is formed by horizontal position control in the X and Y directions and rotation in the 0 direction according to the position adjustment table 20 disposed at the lower portion. Direction and position control, and tilt adjustment control around the X-axis and Y-axis, can perform relative position positioning and parallelism adjustment with the object 4 16 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875 The structure is a relative position positioning and parallelism adjustment that can minimize gap fluctuations when the parts are joined to each other, and is a recognition mechanism that can advance and retreat between the inserts 4 and 5, for example, a two-view recognition mechanism 2 Field-of-view camera), read the recognition mark (not shown) attached to the object 4, 5 or this mechanism, and implement it based on the necessary correction of the position or angle of the read information line. 2 Field of View Meters You can adjust the position in the X and Y directions. You can also adjust the position according to the situation. The relative position positioning and parallelism adjustment are performed in the present embodiment as long as they are performed on the side of the lap joint 17, but may be performed on the side of the lap joint 16 or on both sides. It is necessary to perform not only the lifting control, but also the binary and / or parallel movement control on the 15 side of the joint, and the binary and parallel movement control and the lifting control on the 17 side of the joint. These control patterns are arbitrarily combined. Using the above-mentioned bonding device, the present method is implemented as follows. First, in a processing chamber 7 having a predetermined degree of vacuum, the metal bonding portion bumps of the wafer 4 serving as the bonded object 4 and the metal bonding portion electrodes of the substrate 5 serving as the bonded object 5 are plasma-washed. Surface activation. In the plasma cleaning, the surface foreign matter layer is sufficiently removed to perform surface activation in order to carry out ultrafiltration. Therefore, the entire surface to be joined of the most joined portion can be engraved with an intensity or time of 1 nm or more. As an example, it is the level of an Ar plasma irradiated by a 100 V, slurry washing mechanism for 5 seconds. 312 / Description of the Invention (Supplement) 92-12 / 921263 09 Metal joint structure. In the case of being held 2 1 (for example, the maintenance of the etc., through the implementation of the structure 21 in the Z direction of the structural member 15 or the situation, the root rotation control and rotation control must be clearly connected by A r 2 ( For example, 3 (for example, the sonic bonding is set in metal to set the electric power of 5 0W 17 200406875 the wafer 4 and the substrate 5 that have been cleaned on the surface are temporarily placed in the standby section 12 and the wafer 4 is turned upside down and kept in the overlap The substrate 16 is held on the bonding table 17 without being reversed. The wafer 4 and the substrate 5 held oppositely are based on information read by the recognition mechanism 21 of the 2 field of vision to enter. Position alignment within the specified accuracy, and adjust so that the parallelism also enters the specified accuracy. Especially with regard to parallelism, in order to achieve good ultrasonic bonding, it is best to parallelize the two objects to be joined. It is set to 4 vm or less, and the maximum variation of the gap between the metal joints is adjusted to 4 // m or less. From this state, the bonding tool 16 is lowered, a specified bonding load is applied, and a heater 18 is used as necessary Heating using ultrasonic applicator 1 9 The applied ultrasonic vibrations ultrasonically bond the metal bonding portion 2 (bump) of the wafer 4 and the metal bonding portion 3 of the substrate 5 in the atmosphere. In the conventional ultrasonic bonding, as described above, if the surface of the bonding surface is The oxide film, organic layer, and pollution layer are thicker layers, or When firmly bonded, it is virtually impossible to perform ultrasonic bonding. However, in the ultrasonic bonding of the present invention as described above, energy waves are applied before bonding, and in this embodiment, the surface cleaning by Ar plasma is applied, and the necessary time required for ultrasonic bonding is applied to the surface of the bonding surface. The foreign body layer as described above is sufficiently removed or the surface to be decomposed is sufficiently activated, so that the ultrasonic wave can be applied at a lower intensity (for example, a smaller amplitude than conventional) and can be performed in a shorter time than conventional. The required ultrasonic bonding. Therefore, it is not necessary to forcefully increase the ultrasonic application strength or increase the application time for bonding, and it is also possible to remove the risk of damage to the wafer and bumps from application, thereby ensuring bonding quality. In addition, because the ultrasonic bonding time can be shortened, and the production cycle time of the entire bonding step can be shortened, the production efficiency of 18 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875 liters can be greatly improved. In addition, since the ultrasonic application intensity can be small, the ultrasonic energy capacity can be reduced, and the ultrasonic application mechanism 19 can be miniaturized and inexpensive. Therefore, miniaturization and cost reduction of the entire device can be achieved. In this ultrasonic bonding, as described above, if the surface roughness before joining of at least one metal joint is set to 300 nm or less, or the surface after joining of at least one metal joint is rough The degree is set to 10 nm or less, or the surface hardness of the metal joint portion on at least one side is set to Vickers hardness H v 120 or lower, or the side by heating is effective when joining. Heating can reduce the hardness of the surface or activate the movement of atoms on the surface during bonding, making it easier to perform the required ultrasonic bonding. In particular, the combined effect of heating is great, and it is expected that a multiplicative effect of the effect of heating and the effect of washing by energy waves can be obtained. Especially when heated to 150 ° C, great results can be obtained. In particular, the bonding is performed at a temperature lower than that of the conventional welding, and the low-temperature bonding is maintained compared to the conventional welding, and the effect of cleaning by energy waves is exhibited. However, the heating temperature can be set such that it does not cause an excessive load on the device and does not cause adverse effects on the metal joints due to heating. For example, the heating temperature is appropriately set to 180 ° C or less, and preferably 150 ° Temperature below C (for example, as described above, it is a temperature near 150 ° C or below). In addition, according to the method of the present invention for performing ultrasonic bonding in the atmosphere after washing with energy waves, as shown in the embodiment described later, particularly when the surfaces of the metal bonding portions are all composed of Au, the ultrasonic waves can be lower. The strength of the application and the short application time make the required ultrasonic bonding. However, in the connection method of the invention 19 312 / Invention Specification (Supplement) 92_ 12/92126309 200406875, in order to perform energy wave cleaning in advance, it is not limited to A u / A u bonding, and any of the above metals can be performed. The combination can be, for example, ultrasonic bonding of Au / Cu or Au / A1. If the heating means is used in combination as described above, the ultrasonic bonding of these dissimilar metals can be performed more easily. In order to confirm the operation and effect of the present invention as described above, when performing ultrasonic bonding of metal joints of Au / Au, when ultrasonic bonding is performed without prior plasma cleaning, plasma is performed with or without plasma. In the case of ultrasonic bonding after washing, the effect of heating was confirmed, and tests were performed. Plasma cleaning is an energy treatment that can etch the bump surface as a metal joint to a depth of 1 nm once. As an example, an A r plasma cleaning was performed in a plasma mechanism of 100 V and 50 W for 5 seconds. The evaluation was performed on a bonded body by repeatedly adding a temperature variation between -65 ° C to + 150 ° C, and a thermal shock test was performed to measure the yield (%) of the bump bonding at this time. As a result, the characteristics shown in FIG. 2 can be obtained. As shown in FIG. 2, in the case of performing ultrasonic bonding at normal temperature without prior plasma cleaning, even in a stage with a small number of thermal shock cycles, only a low yield can be obtained. However, by performing plasma in advance Washing (2 irradiations) can achieve high yields up to the stage with many thermal shock cycles. In addition, in order to confirm the effect of heating, high-yield rates can be obtained up to the stage with a large number of thermal shock cycles when ultrasonic bonding is performed without prior plasma cleaning and the temperature during bonding is 150 ° C. . In the result shown in FIG. 2, the effect of heating is higher than that by performing plasma washing in advance. However, this is because the test was performed at a relatively high temperature of 150 ° C. The effect depends on the temperature. However, when the test is performed at a temperature lower than 150 ° C, there may be a case where the effect of prior plasma cleaning is higher. 20 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875. Extremely high results can be obtained both in the case of prior plasma washing and heating, in the case of one plasma washing and in the case of two plasma washings, so it can be known that The combination is the best form. In addition, in the case of performing Au / Au bonding, as compared with the conventional case where only ultrasonic bonding is performed, in order to confirm that the intensity of ultrasonic application can be reduced when performing plasma cleaning in advance in the present invention, A model test to determine the relationship between the amplitude (// m) of the applied ultrasonic wave and the distribution strength (g / bump) of the bonded product. The result is shown in Fig. 3, especially for the application of ultrasound, and it is used by ordinary users now. In the conditions of this model test, the amplitude of the ultrasonic wave is compared, and the ultrasonic wave of the present invention is reduced to 4 // m, and it can still be confirmed that the effect of plasma washing on the application can be confirmed. Ultrasonic vibration can be reduced. In addition, as a pricer, it can also contribute to the ultrasonic energy necessary for the entire joining of the device. The time can also be shortened, which can shorten the production cycle time of the entire joining process. Occasionally, there is no condition on the surface, even if the organic matter is not joined by the oxygen plasma of the decompression plasma forced pulp mechanism. As shown in the model test, larger bumps are formed on the wafer to confirm the effect of plasma cleaning in advance. In the conventional method of applying a degree of 10 #in, it can be confirmed that The same bonding strength is obtained, so that the reduction of the ultrasonic intensity can be added to a larger extent, which means that the loss applying mechanism of the wafer and the bump can also be made small, inexpensive, and low cost. In addition, it can be seen that it can be made small, so that the time required for the application of the ultrasonic wave can further reduce the connection time. In addition, the metal joint is oxidized and is only organic. In this case, etching can also be performed using atmospheric piezoelectricity, and subsequent ultrasonic waves can be performed. 21 312 / Invention Specification (Supplement) 92-12 / 921263 09 200406875 In addition, with the rapid development in recent years, metal joints ( (Bumps) with extremely small gaps and finely spaced wafers, that is, it is conventionally necessary to apply ultrasonic waves having an amplitude of 3 // m or more for ultrasonic bonding. The method of the present invention can perform the same model test described above. Fig. 4 shows the relationship between the test results and the distribution strength (g / bump) of the bonded product. By performing plasma cleaning in advance, it can be seen that excellent effects can be obtained with ultrasonic amplitudes less than 3 // m. That is, at an amplitude of 3 // m, there is a slight crack in the bump, but at an amplitude of 2 // m, there is no crack at all. In addition, joining can be performed at an amplitude of 1 // m. In addition, in this model test, FIG. 5 shows the measurement of the collapse of the bumps when no ultrasonic waves were applied to the bumps (material: Au, hardness: 60 H v, initial surface roughness: 300 nm). The result of the amount and joint load. As shown in FIG. 5, in the conventional room temperature bonding, in order to achieve a good bonding (bump collapse amount: 1 μm or more, surface roughness after bonding: 10 nm or less), 3 0 Μ Pa The joint load is 50%, but the same effect can be obtained with half of the joint load of 150 MPa by applying ultrasonic waves. Fig. 6 shows the relationship between the yield after bonding and the frequency at which the ultrasonic wave is applied when an ultrasonic wave having an amplitude of 1 // m is applied in the method of the present invention. As shown in Fig. 6, using a frequency of 40 k Η z or more, especially 60 k Η z or more, even a supersonic wave having an amplitude of 1 // Π1 can still obtain extremely excellent results. In this way, especially through the above-mentioned model test, it is known that in the conventional ultrasonic bonding, a bonding load of 300 MPa or more is required, but in the method of the present invention, the bonding can be successfully performed with a bonding load of 150 MPa. . (Industrial availability) 22 312 / Invention Specification (Supplement) 92-12 / 92126309 200406875 The bonding device and method of the present invention can be applied to any ultrasonic bonding between objects to be bonded having metal bonding portions, especially This is an ultrasonic bonding suitable for a case where at least one of the objects to be bonded is a semiconductor. [Brief Description of the Drawings] FIG. 1 is a schematic configuration diagram of a bonding apparatus according to an embodiment of the present invention. Figure 2 shows the relationship between the thermal shock test cycle and the yield. Fig. 3 is a diagram showing the relationship between the ultrasonic amplitude and the distribution intensity of the model test. Figure 4 is a graph showing the relationship between the ultrasonic amplitude and the distribution intensity (relative value) of another model test. Fig. 5 is a graph showing the relationship between the joint load and the bump collapse amount in a model test. Figure 6 is a graph showing the relationship between the frequency and the yield (relative value) of the ultrasonic application test with an amplitude of 1 // m. (Description of element symbols) 1 Bonding device 2 Metal bonding portion 3 Metal bonding portion 4 Bonded object (wafer) 5 Bonded object (substrate) 6 Vacuum pump 7 Processing chamber 8 Plasma irradiation mechanism 9 Plasma 10 A r gas supply pump 11 Joint device part 23 312 / Invention specification (Supplement) 92-12 / 92126309 200406875 12 Standby part 13 Reversing mechanism 14 Head of reversing mechanism 15 Lap joint 16 Lap tool 17 Lap table 18 Heating as heating mechanism Device 19 Ultrasound application mechanism 20 Position adjustment table 21 2 Field of view recognition mechanism 312 / Invention manual (Supplement) 92-12 / 92126309