絕緣層上鍺晶圓製程及其特性

Abstract

本論文中，我們經由晶圓鍵結結合氫離子佈植技術，成功地將鍺薄膜層轉移至一有50奈米二氧化矽覆蓋的矽晶圓上，並且做出絕緣層上鍺之結構。因為鍺擁有高的載子遷移率且具有吸收紅外光的能力，使其成為在高速光偵測器應用上的最佳選擇。為了減少鍺層的表面粗糙度進而降低暗電流，第二階段的氣氛退火（10％氫氣與90％的氮氣）為可行的方法之一。 因為玻璃基板可以達到降低成本的目標且可使用於背面入射的應用上，所以玻璃基板是一個好的代替品來取代覆蓋二氧化矽的矽晶圓。當蝕刻鍺層的表面時，我們可以得到較低的暗電流並且提升可見光下的光響應。若在玻璃上覆鍺的結構上做選擇性的蝕刻，便可達到在同一晶片上在未蝕刻的部分來偵測紅外光而蝕刻的部分偵測可見光的好處。此外，當歐姆接觸從鋁轉換成銦錫氧化物，則此結構便可運用在太陽能電池的技術發展上。 再來，塑膠膜亦可以結合晶圓鍵結與氫離子佈植技術達成鍺薄膜轉移，製造出塑膠膜上覆鍺之結構，並且做出塑膠膜上覆鍺-金氧半-光偵測器。可撓性電子元件將具有相當的潛力於應用在可攜式與可捲曲式的顯示器，感測器/促動器，生醫元件與射頻識別晶片…等的運用上。

In this thesis, the thin film germanium layer is transferred successfully to another silicon wafer capped with about 50 nm SiO2 by direct wafer bonding and hydrogen-induced layer transfer and formed the germanium-on-insulator (GOI) structure. The high mobility of germanium and the ability of germanium to absorb in the infrared make it a promising candidate in high-speed photodetector application. To reduce the surface roughness of germanium layer for decreasing the dark current, the second annealing in forming gas (i.e. H2 10%) is one of the workable methods. Because the glass substrate can reach the goal of low cost and could be used for back incident application, the glass substrate is a good substitute for silicon wafer capped with SiO2. Etching the surface of germanium layer could decrease the dark current and increase the responsivity under the visible light exposure. The selectively etching on germanium-on-glass (GOG) structure can achieve visible light and infrared detection on the same chip with the unetched part for infrared detection and the etched part for visible light detection. Furthermore, the ohmic contact is exchanged from aluminum to indium-tin-oxide (ITO) to apply on the GOG substrate for back incident application. This germanium-on-ITO glass structure could be used for solar cell technology. Afterward the polyimide substrate is combined with the techniques direct wafer bonding and hydrogen-induced layer transfer to fabricate the germanium-on- polyimide (GOP) structure and GOP MOS photodetector for the potential application in flexible electronics. That is feasible for its applications in portable and roll-able display, sensors/actuators, medical devices and RF identification.