Fabrication and Characterization of Al.25Ga.75N/GaN High Electron Mobility Transistors with Indium Tin Oxide Gate
劉秉承、廖豐標
E-mail: [email protected]
ABSTRACT
AlGaN/GaN HEMTs are attractive devices for high power switching applications because of their high electron mobility and high breakdown characteristics. In this paper, we fabricate photo transistor by using ITO instead of gate metal. Therefore, the
characteristics of the transparent by using ITO, the light source could through the interface of AlGaN/GaN and then obtained the electron-hole pair which has the duality of photodetector and transistor for HEMT. The light signals were be amplified by the photo-transistor instead of a conventional photodetector, and when the conventional photodetector is used, an amplifier is required to increase resolution. We characterized and compared HEMTs with ITO gates when not shining on light and shining on light. We characterized and compared HEMTs with ITO gate and Ni/Au gate as well. The results will be presented in the thesis. HFETs having ITO gates with a gate-with of 25 μm and a gate-length of 1 μm demonstrated the largest source-drain current (Ids) of 13.8 mA, and the largest transconductance of 113.6 mS/mm at a gate voltage of 0 V under without light.
Keywords : ITO gate fingers ; AlGaN/GaN HEMT ; Optical control of microwave devices ; Transparent-gate HEMT Table of Contents
封面內頁 簽名頁 博碩士論文電子檔案上網授權書．．．．．．．．．．．．．．．．．．．．．．．．iii 中文摘要．．
．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．iv 英文摘要．．．．．．．．．．．．．．．．
．．．．．．．．．．．．．．．．．．v 誌謝．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．
．．．．vi 目錄．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．vii 圖目錄．．．．．．
．．．．．．．．．．．．．．．．．．．．．．．．．．．．．x 表目錄．．．．．．．．．．．．．．．．．．．．
．．．．．．．．．．．．．．．xii 第一章序論．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．
．．1 1.1研究動機．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．1 1.2論文架構．．．．．．
．．．．．．．．．．．．．．．．．．．．．．．．．．．4 第二章氮化鋁鎵/氮化鎵高電子遷移率電晶體工作原理．．
．．．．．．．．．．．．．5 2.1氮化鋁鎵/氮化鎵高電子遷移率場效電晶體工作原理與介紹 ．．．．．．．．．．．5 2.2氮化鋁鎵/氮化鎵極化效應與表面效應．．．．．．．．．．．．．．．．．．．．10 2.3氮化鋁鎵/氮化鎵對於光的吸 收．．．．．．．．．．．．．．．．．．．．．．．14 2.4閘極蕭特基接觸原理 ．．．．．．．．．．．．．．．．．
．．．．．．．．．．17 2.5歐姆接觸原理 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．22 2.6傳輸 線模型理論 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．29 2.7銦錫氧化物薄膜理論 ．．．．．．．
．．．．．．．．．．．．．．．．．．．．32 第三章 元件製作與測試實驗 ．．．．．．．．．．．．．．．．．．．
．．．．． 40 3.1元件製作 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． 40 3.2平台隔離製作 ．
．．．．．．．．．．．．．．．．．．．．．．．．．．．．．41 3.3歐姆接觸測試製程與量測 ．．．．．．．．．．
．．．．．．．．．．．．．．．43 3.4 ITO退火參數測試．．．．．．．．．．．．．．．．．．．．．．．．．．．
． 50 3.4.1 ITO穿透率量測與分析 ．．．．．．．．．．．．．．．．．．．．．．．．．53 3.4.2 ITO電阻率之量測與分 析 ．．．．．．．．．．．．．．．．．．．．．．．．58 3.5閘極蕭特基接觸測試製程 ．．．．．．．．．．．．．．
．．．．．．．．．．．61 3.6氮化鋁鎵/氮化鎵高電子遷移率場效電晶體製程．．．．．．．．．．．．．．．．65 3.6.1 平台製作（Mesa Isolation)．．．．．．．．．．．．．．．．．．．．． 65 3.6.2汲極跟源極歐姆接觸（Drain and Source Ohmic Contact）．．．．．．． 67 3.6.3 閘極蕭特基接觸（Gate Schottky Contact）．．．．．．．．．．．．．．69 第 四章氮化鋁鎵/氮化鎵高電子遷移率場效電晶體電性量測結果．．．．．．．．．．．71 4.1在沒照光下，傳統以鎳/金為 閘極與以ITO為閘極之HEMT量測與比較．．．．．．．71 4.2 以ITO為閘極之HEMT在照光與無照光情況下量測與比較
．．．．．．．．．．．．75 4.3 以ITO薄膜所製之蕭特基二極體照光之特性．．．．．．．．79 第五章 結論 ．．．．
．．．．．．．．．．．．．．．．．．．82 參考文獻．．．．．．．．．．．．．．．．．．．．．．．．．84 REFERENCES
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