本論文主要針對在矽(111)基板上進行氮化鋁鎵/氮化鎵高電子遷移率電晶體製作與研究，希望藉由改變氮化鎵表面層的厚度及鎂離子摻雜濃度，研究不同氮化鎵表面層在元件的直流電特性和動態電流崩塌效應。 為了觀察三種不同p型氮化鎵磊晶表面層的氮化鋁鎵/氮化鎵高電子遷移率電晶體的電特性差異，實驗採用相同鎂離子活化條件和相同的元件製程步驟，鎂離子活化條件為氮氣環境下700°C 15分鐘。元件閘極漏電流，在增加氮化鎵表面層厚度後可下降約一個數量級，不過受到氮化鎵表面層極化的影響，元件會有相對低的汲極電流。藉由蕭特基閘極的分析，在增加氮化鎵表面層厚度後，元件觀察到相對高的蕭特基能障。 在元件脈衝電流測量下，比較不同的靜止點偏壓條件(quiescent point)，觀察元件開啟後的電流狀態，發現較厚的氮化鎵表面層的元件在動態電阻/穩態電阻比值有較優異的表現。 ;In this paper, we focus on the fabrication and research of p-GaN cap in AlGaN/GaN high electron mobility transistors (HEMTs) on silicon (111) substrates. By changing the thickness and Magnesium ion doping concentration of GaN cap layer, DC characteristics and dynamic current collapse effect of devices are investigated. In order to observe the electrical properties of AlGaN/GaN HEMTs in three different p-type GaN epitaxial cap layers, the same Mg ion activation conditions and the same process were used. The activation conditions are annealing in a N2 ambient at 700 ° C for 15 minutes before device fabrication. The gate leakage current can be reduced by about one order after increasing the thickness of the GaN cap layer, but device shows a relatively low drain current. With the analysis of the Schottky gate, the device shows a relatively high Schottky barrier height after increasing the thickness of the GaN cap layer. Devices were measured with the pulse IV measurement under different quiescent bias points, the on-state current was compared. Device with the thicker GaN cap layer had better Ron,stresss/Ron,no stress ratio.
