博士 / 國立臺灣大學 / 光電工程學研究所 / 103 / In this thesis, we present an enhancement-mode AlGaN/GaN fin-shaped metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMT), fabricated by combining gate recess process and fin-shape structure, featuring double-layer oxides composed of photo-enhanced-chemical (PEC) oxidation and plasma-enhanced atomic layer deposition (PE-ALD) oxide, which was shown to support threshold voltage (Vth) with a linear slope of 0.36 V/nm and -0.32 V/μm2, respectively, scaled with recess depth and device area. The proposed device exhibited Vth = 1.2V, current on/off ratio of 10^8, and cutoff frequency of unity current gain/power gain (fT/fmax) = 9/36GHz at gate length/width = 250/360nm. These observations can be ascribed to the combination effects of (a) interfacial negative space charge of 3.2 μC/cm2 in the gate-recessed device to partially compensate the polarization charges, and (b) side-wall passivation to preserve the high mobility channel.
| Identifer | oai:union.ndltd.org:TW/103NTU05124131 |
| Date | January 2015 |
| Creators | Po-Chun Yeh, 葉伯淳 |
| Contributors | 彭隆瀚 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 133 |
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