研究生: |
高璿皓 |
---|---|
論文名稱: |
高電流密度氮化銦/氮化鋁電晶體 High Current Density InN/AlN MISHFETs |
指導教授: |
徐碩鴻
柳克強 |
口試委員: | |
學位類別: |
碩士 Master |
系所名稱: |
原子科學院 - 工程與系統科學系 Department of Engineering and System Science |
論文出版年: | 2007 |
畢業學年度: | 95 |
語文別: | 中文 |
論文頁數: | 56 |
中文關鍵詞: | 氮化銦/氮化鋁電晶體 |
外文關鍵詞: | InN/AlN MISHFETs |
相關次數: | 點閱:2 下載:0 |
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此論文驗證了,氮化銦/氮化鋁 MIS異質介面電晶體,有明顯的電流調變和夾止電流效應。 此元件的高品質氮化銦(26 nm)/ 氮化鋁(100 nm)是使用電漿輔助分子磊晶技術而成,長在(111)的矽基板上。
此元件在閘極長度為5-□m下,有著極高的電流密度,其電流密度可大於530 mA/mm。元件的夾止電壓的量測值在 –7伏左右,而此對應的汲極漏電流小於10 □A/mm。如此高濃度的電流密度極有可能是因為氮化銦和氮化鋁之間很大的自發性極化所造成如此高的片電流密度所致。
以三族氮化合物來做作異質結構場效電晶體在高頻、高功率微波領域上一直是當今熱門的研究課題。異質結構場效電晶體大多以GaN和GaAs為主。而近幾年的研究中,氮化銦(InN)已廣泛地被注意到,且相當被看好。研究資料顯示當此材料作元件模擬中,其截止頻率可望達到THz,是未來極有可能發展成為操作在THz的元件[1]。但在目前的研究文獻中,僅僅侷限在理論推導,尚未有實際元件的完成及其量測結果。
以材料特性來說,InN比起GaN及GaAs來說,具有更高的電子遷移率(Electron Saturation),漂移速度(Drift Velocity)、峰值電子漂移速度(Peak Overshoot Drift Velocity) [1]。其二維電子氣片電子濃度(Sheet Carrier Concentration)可達到1.01x1014 cm-2以上[2]。這較傳統AlGaN/GaN系列異質結構的二維電子氣濃度高出一個數量級,且也較一般傳統結構的AlGaAs/GaAs高兩個數量級。如此高的二維電子氣平板電子濃度使得InN系列的高速場效電晶體能夠在輸出大電流工作,並且使其有機會可操作在THz。接著電性與材料特性簡介分述如下。
Abstract
InN/AlN metal-insulator-semiconductor heterojunction field-effect transistors with a gate-modulated drain current and a clear pinch-off characteristic have been demonstrated. The devices were fabricated using high-quality InN (26 nm)/AlN (100 nm) epifilms grown by plasma-assisted molecular-beam epitaxy on Si (111) substrates. The devices exhibited a current density higher than ~530 mA/mm with a 5-□m gate length. The pinch-off voltage was at ~ –7 V with an associated drain leakage current less than 10 □A/mm. The observed high current density may be attributed to the high sheet carrier density due to the large spontaneous polarization difference between InN and AlN.
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