Embedded-Ge source and drain in InGaAs/GaAs dual channel MESFET

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• 作者：Shang-Chao Hung ; Qiuping Luan ; Hau-Yu Lin ; Shuguang Li ; Shoou-Jinn Chang
• 关键词：III&ndash ; V ; InGaAs MESFET ; Heterostructure ; Embedded-Ge S/D
• 刊名：Current Applied Physics
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：13
• 期：8
• 页码：1577-1580
• 全文大小：1377 K

文摘

We report the first demonstration of n-type III-V metal-semiconductor field-effect transistors (nMESFETs) with IV group material hetero-junction source and drain (S/D) technology. A selective epitaxial growth of germanium (Ge) in the recessed gallium arsenide (GaAs) S/D regions is successfully developed using ultra-high vacuum chemical vapor deposition (UHVCVD) system. The dual channel structure includes an additional 10-nm higher mobility n-In_0.2Ga_0.8As layer on n-GaAs channel and is introduced to further improve the device performance. The n-MESFET, combining embedded-Ge S/D with In_0.2Ga_0.8As/GaAs channel, exhibits good transfer properties with a drain current on/off ratio of approximately 10³. Due to the small barrier height of Ti/In_0.2Ga_0.8As Schottky contact, a lattice-matched wide bandgap In_0.49Ga_0.51P dielectric layer is also integrated into the device architecture to build a higher electron Schottky barrier height (SBH) for gate leakage current reduction. The Ti/In_0.49Ga_0.51P/n-In_0.2Ga_0.8As Schottky diode shows a comparable leakage level to Ti/n-GaAs with 2?¡Á?10^?2?A/cm² at a gate voltage of??2.0?V.