標題: | 銻化物高電子遷移率電晶體研究 Studies of Sb-based High Electron Mobility Transistors |
作者: | 李孟穎 Li, Meng-Ying 李建平 Lee, Chien-Ping 電子研究所 |
關鍵字: | 銻化物;三五族;高電子遷移率電晶體;砷化鎵;糾結效應;軟性崩潰電壓;Sb;III-V;HEMT;GaAs;Kink effect;soft-breakdown |
公開日期: | 2010 |
摘要: | 這篇論文主要是研究銻(Sb)化物材料的高電子遷移率電晶體元件(HEMT)的
開發。由於銻化物材料和砷化鎵(GaAs)基板之間的晶格差異很大,所以在使用分
子束磊晶系統(MBE)的過程需要透過變晶成長的方式進行磊晶。藉由實驗我們成
功成長出高電子遷移率的試片(22700cm2V-1s-1)。此外,對於閘極長度為2um 的
電晶體,傳導率(transconductance)為730mS/mm。對於閘極長度為50nm 的電晶
體,其截止頻率(ft)和最大震盪頻率(fmax)分別為50GHz 和5GHz。
除此之外,由於銻化物材料本身的能帶間隙非常的小,因此元件在操作的過
程很容易就產生碰撞游離,造成糾結效應(Kink effect)。本研究也展示了透過主動區的結構調整,可以加大能帶間隙,進而提高糾結效應所造成的軟性崩潰電壓(soft-breakdown voltage)。 This thesis focuses on the development of Sb-based High Electron Mobility Transistor (HEMT). In this work, because of the large lattice mismatch, the Sb-based HEMT is grown on semi-insulating GaAs substrate by using metamorphic MBE growth. The best electron mobility we obtained is 22700cm2V-1s-1 by experiments. In addition, the fabricated device showed the maximum transconductance is 730mS/mm at a high drain bias Vd=1.6V for a 2um gate length device. The cut-off frequency (ft) is 50GHz and the maximum oscillation frequency (fmax) is 5GHz for a 50nm gate length device. Furthermore, due to the narrow band gap of Sb-based material, the device would generate impact ionization easily and cause the kink effect. This work also demonstrates the adjustment of the channel structure to enlarge the soft-breakdown voltage resulting from kink effect. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079811504 http://hdl.handle.net/11536/46687 |
顯示於類別: | 畢業論文 |