利用有機金屬化學氣相沉積法探討使用鎵/銻介面處理對於成長銻化鎵薄膜於砷化鎵基板之影響

Abstract

近年來，由於半導體製程微縮，傳統的金氧半場效電晶體在製程微縮下將面臨閘極漏電流的問題。為了解決這個問題，必須引入新材料以及新的電晶體架構。基於銻化物的穿隧式場效電晶體將是未來的解決方案之一，但由於銻化物與常用砷化鎵基板之間存在著極大晶格不匹配，於是如何克服材料間晶格不匹配產生之應力及缺陷便成為極為重要的課題。 在本研究中，探討直接成長銻化鎵於砷化鎵基板，其銻化鎵/砷化鎵介面處理參數對於銻化鎵初期成長之影響，透過三甲基鎵介面流量、時間以及三甲基銻介面流量、時間之參數調變，取得銻化鎵初始成長之垂直、側向成長速率比。本研究中發現使用三甲基銻介面處理能夠有效地降低表面能以利於側向成長銻化鎵薄膜，以利減少晶體缺陷形成，透過最佳化三甲基銻界面處理，我們可以在75nm的厚度內達到1.7nm的RMS表面粗糙度及XRD rocking curve 半高寬為371 arcsec 的高品質銻化鎵薄膜。

In recent years, due to scaling down of the semiconductor manufacturing process, traditional MOSFET will meet the problem of gate leakage current. In order to solve this problem, it is needed to introduce new materials and new device structures. Antimonide based tunneling FET may be one of the solution in the future. However, lattice mismatch between antimonide and commercial GaAs wafer is too large, it is very important to overcome the strain and defects that produced due to lattice mismatch. In this study, direct growth of GaSb on GaAs substrate has been investigated. Effects of GaSb/GaAs interfacial treatment parameters on the GaSb initial growth mode has been discussed in this work. By modulating TMGa flux and flow time, TMSb flux and flow time, we got the information of the vertical/lateral growth ratio of GaSb island. We discovered that when we use TMSb as interfacial treatment, it effectively lowers the surface free energy and promotes lateral growth mode of GaSb growth. By optimizing TMSb interfacial treatment, we can get 75 nm high quality GaSb thin film with surface roughness 1.7 nm and FWHM of XRD rocking curve is 371 arcsec.