本研究發現以低溫電化學方式，能夠進行銅與矽晶圓直接鍵合。透過 低溫環境，降低溫度對擴散的影響，探討電場驅動擴散反應。 晶圓鍵合技術一般需要極度光滑之試片表面與非常高溫的熱處理，本 實驗發現以電化學法能夠產生直接鍵合，不須經過拋光與退火等程序，且 其鍵合強度極高。研究中發現更勝於銅抗拉強度之鍵合，使二試片分離時 部分銅片破裂並殘留於矽晶表面。 除了表面鍵合外，本論文也將探討電場引導的擴散現象。一般而 言，-70℃之環境下，上不可能出現明顯及快速的擴散現象，但實驗中僅以 30分鐘的實驗時間，產生了深達數微米的銅離子擴散現象。;Wafer bonding technology generally require high-temperature heat treatment or extremely smooth surface condition. However, in our recent research, a strong bonding phenomenon between copper and silicon wafer was discovered in a liquid-nitrogen submerged device, with aid from external electric field. Minimum surface roughness and high-temperature heat treatment are not required in such bonding technique. Furthermore, if the copper-silicon interface was separated by force, a thin layer of copper on silicon wafer can be visible to the naked eyes. Indicate the bonding strength is stronger than the tensile stress of copper, therefore leaving a thin layer after been split apart. In addition, this thesis will also discuss the abnormally rapid diffusion of positively charged copper ions in silicon crystal at -70℃. Generally, diffusion is extremely temperature sensitive. Yet in our bonding experiment, rapid diffusion of copper ions can be observed by SIMS. We suggest that external electric field can provide the kinetic energy, which is normally provided by temperature, to ions in order to surpass activation energy.
