利用快速熱熔磊晶法及表面鈍化製作金屬－鍺－金屬光偵測器

Metal-Ge-Metal Photodetector Fabricated by Rapid-Melting-Growth Method with Surface Passivation

曾治國(Chih-Kuo Tseng) ； 吳庭孝(Ting-Hsiao Wu) ； 洪偉誠(Wei-Cheng Hung) ； 田仲達(Jhong-Da Tian) ； 那允中(Neil Na) ； 李明昌(Ming-Chang Lee)

《科儀新知》 190期 (2012/10) Pp. 48-54

https://doi.org/10.29662/IT.201210.0007

摘要

幾十年來，矽半導體產業擴展迅速，由於先進的CMOS製程技術、矽材料性能穩定以及材料成本相對較低，因此矽基光電子學在近期得到相當多的關注。關鍵應用之一是高速光偵測器於光通訊或光連接產業。然而，光通訊所使用的紅外線波長對於矽而言是透明的，應結合其他材料並整合在矽光電元件來偵測紅外光信號。鍺是一種長波長吸收的理想材料。同時，鍺元件的製作過程與CMOS製程相容，表示它具有量產的能力。鍺基光偵測器製作於於矽基板上已經被許多研究團隊所研究。最關鍵的問題是如何克服矽與鍺在磊晶過程當中晶格不匹配的問題。在這篇論文中，我們提出低熱預算的快速熱熔磊晶方法（rapid melting growth）來成長高品質的金屬－單晶鍺－金屬光偵測器於矽基板上，同時藉由適當的金屬接觸及鍺的表面鈍化使得元件的暗電流顯著減少三個數量級。

並列摘要

Over decades, silicon semiconductor industry grew rapidly due to the advancement of CMOS fabrication technology, as well as the relatively low cost and good material stability. Recently, silicon-based optoelectronics that is capable of being integrated with modern IC receives a lot of attention. One of the key applications is high-speed photodetector for telecommunication and optical interconnect. However, Si is transparent at infrared wavelengths that are usually used in optical communication. Other materials should be used in adjunction with Si substrate to detect infrared signals. Ge is an ideal material for long wavelength absorption; moreover, Ge process is CMOS process-compatible, indicating the possibility of mass production. Ge-based photodetectors on silicon substrate have been studied by several research groups. One of the key issues is the difficulty in epitaxy growth of Ge on silicon due to lattice mismatch (4%). In this paper, we apply rapid melting growth method to grow high-quality single-crystal metal-semiconductor-metal Ge photodetectors on oxide with low thermal budget. By carefully selecting the metal contact and Ge passivation, the device dark current is significantly reduced by three orders of magnitude compared to the state-of-art literature data.