氮化鎵材料的寬能隙、高臨界電場、高電子飽和速度和高導熱係數 材料特性使其在高速及高頻元件領域內成為相當熱門的研究主題。其中， 由氮化鋁銦作為阻障層的氮化鋁銦/氮化鎵異質接面場效電晶體由於晶格 匹配，無應力問題，且其自發性極化產生相當高的二維電子氣濃度，使 其在非常適合用於高頻元件。然而其漏電流特性使之不易達到如氮化鋁 鎵/氮化鎵元件可以達到的高壓特性。

本篇論文透過改變閘極蝕刻深度和沉積氧化鋁絕緣層，形成金屬— 絕緣層—半導體高電子遷移率電晶體，藉此提高其崩潰電壓。並維持其 高頻特性。透過元件製程並量測，雖然由於氧化鋁絕緣層沉積後，在金 屬—絕緣體接面和絕緣體—半導體接面之間產生的缺陷，以及閘極蝕刻 深度未最佳化，導致元件的直流特性不佳，但實驗結果仍證明沉積氧化 鋁絕緣層能有效的提高元件的崩潰電壓，其中最好的元件表現提升了
62.5%，而高頻的部分則可達到 f max = 4.38GHz 和 f T = 1.95GHz。若進
一步最佳化蝕刻深度並在氧化鋁絕緣層沉積後進行退火減少缺陷，可預 期元件表現能更為提升。

Research in high power and high frequency devices on Gallium-Nitride- based High Electron Mobility Transistor(HEMT) has become more and more popular due to their outstanding material characteristics which including wide bandgap, high critical electric field, high electron saturation velocity, and high thermal conductivity. Among them, owing to the high density of two-dimension electron gas only depending on the spontaneous polarization without strain introduced by lattice match, the InAlN/GaN Heterojunction Field Effect Transistor using InAlN as barrier layer is suitable for high frequency applications. However, the high leakage current and low breakdown of InAlN/GaN device is still an issue for achieving high power performance.

In this thesis, MIS-HEMT using Al2O3 as the insulator layer with different
gate recess depths was investigated to increase the breakdown voltage while
maintaining good high frequency performance. The defects and traps generated at
the Metal-Insulator interface and Insulator-Semiconductor interface and the non-
optimized gate recess depth could be responsible to the relatively poor DC
performance of the transistors. However, the result still shows that using Al2O3 as
insulator layer can improve the breakdown voltage up to 62.5%. In addition,
device achieves frequency performance with f_max=4.38GHz and
f_T = 1.95GHz. With optimizing the depth of gate recess and annealing device after the deposition of Al2O3 insulator layer, the improvement of performance can be expected.

摘要----------------------------------------------------------------------------------------------------------------------------i
ABSTRACT --------------------------------------------------------------------------------------ii
誌謝--------------------------------------------------------------------------------------------------------------------------iii
目錄--------------------------------------------------------------------------------------------------------------------------iv
圖表目錄 -----------------------------------------------------------------------------------------------------------------vii
表格目錄 ------------------------------------------------------------------------------------------------------------------ix
第一章 緒論 --------------------------------------------------------------------------------------------------------------1
1.1 研究背景與動機----------------------------------------------------------------------------------------------1
1.2 論文架構 ---------------------------------------------------------------------------------------------------------2
1.3 本章結論 ---------------------------------------------------------------------------------------------------------2
第二章 氮化鋁銦與異質接面電晶體------------------------------------------------------------------------3
2.1 材料特性 ---------------------------------------------------------------------------------------------------------3
2.1.1 寬能隙材料 ----------------------------------------------------------------------------------------------3
2.1.2 電子遷移率及電子飽和速度 -------------------------------------------------------------------3
2.1.3 導通電阻及崩潰電壓-------------------------------------------------------------------------------4
2.2 氮化鋁銦/氮化鎵異質接面場效電晶體 ----------------------------------------------------------5
2.2.1 元件結構 --------------------------------------------------------------------------------------------------5
2.2.2 阻障層材料 ----------------------------------------------------------------------------------------------6
2.2.3 氮化鋁隔層 ----------------------------------------------------------------------------------------------9
2.2.4 緩衝層 ------------------------------------------------------------------------------------------------------9
2.3 高頻氮化鋁銦/氮化鎵異質接面場效電晶體-------------------------------------------------10
2.3.1 元件截止頻率-----------------------------------------------------------------------------------------10
2.3.2 短通道效應 --------------------------------------------------------------------------------------------11
2.4 本章結論 -------------------------------------------------------------------------------------------------------15
第三章 元件設計及製程介紹----------------------------------------------------------------------------------16
3.1 氮化鋁銦/氮化鎵高電子遷移率電晶體元件設計-----------------------------------------16
3.2 黃光微影製程------------------------------------------------------------------------------------------------17
3.3 元件製程 -------------------------------------------------------------------------------------------------------18
3.3.1 隔離平臺製作-----------------------------------------------------------------------------------------18
3.3.2 歐姆接觸 ------------------------------------------------------------------------------------------------19
3.3.3 閘極掘入 ------------------------------------------------------------------------------------------------21
3.3.4 氧化鋁絕緣層製作及接觸窗口製作 ------------------------------------------------------21
3.3.5 蕭特基閘極及襯墊金屬層製作--------------------------------------------------------------22
3.3.6 鈍化層製作及接觸窗口製作------------------------------------------------------------------23
3.3.7 接線金屬製作-----------------------------------------------------------------------------------------24
3.3.8 實際元件 ------------------------------------------------------------------------------------------------25
3.4 量測方式 -------------------------------------------------------------------------------------------------------26
3.4.1 傳輸線量測方法-------------------------------------------------------------------------------------26
3.4.2 外部參數去嵌入萃取 -----------------------------------------------------------------------------27
3.5 本章結論 -------------------------------------------------------------------------------------------------------29
第四章 量測結果與討論 -----------------------------------------------------------------------------------------31
4.1 量測結果 -------------------------------------------------------------------------------------------------------31
4.1.1 元件量測結果—直流 -----------------------------------------------------------------------------33
4.1.2 元件量測結果—高頻 -----------------------------------------------------------------------------49
4.2 討論 — 關於氧化鋁絕緣層--------------------------------------------------------------------------52
4.3 本章結論 -------------------------------------------------------------------------------------------------------54
第五章 總結及未來工作 -----------------------------------------------------------------------------------------55
5.1 總結 ---------------------------------------------------------------------------------------------------------------55
5.2 未來工作 -------------------------------------------------------------------------------------------------------55
參考文獻------------------------------------------------------------------------------------------------------------------57

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