錫銀銅銲錫薄膜於電遷移效應下之研究

Abstract

本論文使用不同長度之錫銀銅銲錫薄膜結構的邊緣移動技術來計算錫銀銅銲錫薄膜受電致遷移之參數，試片結構經圖案化後銅/鈦結構，經由迴銲和拋光形成Blech結構，之後利用focus ions beam（FIB）切割成不同長度，後續再利用掃瞄式電子顯微鏡與原子力顯微鏡觀察不同長度之錫銀銅銲錫薄膜Blech結構在通電前後的之變化，經計算可得到該電流密度下與溫度下之門檻長度。這些數值代表錫銀銅銲錫在該電流密度與溫度下不會經由電遷移效應之破壞的最短長度。

Critical length of lead-free solder has not been measure because it is very difficult to prepare short solder stripe. In this study, By employing focus ion beam, solder stripes of various lengths, including 5, 10, 15, 20, 30, 100, and 200 μm, can be fabricated. Length dependent electromigration behavior was observed, which implies that there may be back stress under current stressing. We can determine the critical length under testing condition under 2~4×104 A/cm2 at 100-150℃, the critical product is 20~30 A/cm and critical length is 10~15 μm