摘 要 通道摻雜異質接面場效應電晶體具有高電流推動能力，以及元件功率特性及效能。由於此高電流推動能力及熱穩定性，因此廣泛地應用在微波功率元件及高速元件上。 然而閘極漏電流經常限制了通道摻雜異質接面場效應電晶體元件的功率特性，由其在高輸入功率時。先我們利用鐠金屬來加入鈦/金金屬閘極的製作，來改良元件之閘極漏電流，進而改善整體元件功率特性及效能。 為了要大幅度增加功率元件的崩潰特性，多數製程採用雙重曝光暨雙重閘極蝕刻來改善元件崩潰電壓之特性，我們利用電子束微影設備來開發單次直寫微影技術配合乾蝕刻及溼蝕刻的雙重掘入技術來改善銦砷化磷-銦砷化鎵通道摻雜場效應電晶體的輸出功率特性。 最後，我們利用埋入式鉑金屬技術來製作增強及空乏型深次微米T型閘極異質結構鋁砷化鎵-銦砷化鎵電晶體，進行一系列元件直流，高頻，以及功率方面之研究。接著我們完成增強及空乏型反相器及差動式放大器電路。 ABSTRACT Doped-channel heterostructure field-effect transistors (DCFETs) with a high current density and superior microwave power performance was developed and characterized. Due to its excellent current driving capability and thermal stability, it has been widely investigated for microwave power devices and high-speed devices. However, gate leakage current always limits the power performance of DCFETs devices especially under a high input power swing. We interested in improving the Schottky gate performance by inserting a thin praseodymium (Pr) metal layer on the bottom of conventional Ti/Au gate in AlGaAs/InGaAs DCFET fabrication. We suppress the gate leakage current and enhance microwave power performance by Pr metal gate deposition. In chapter 3, we use the single exposure e-beam direct writing method plus the selective wet and dry etchings to fabricate double-recessed DCFETs (DR-DCFETs) and to improve device power performance. The 0.2 µm gate length InGaP/InGaAs DR-DCFET was developed and characterized. In chapter 4, we fabricated enhancement/depletion-mode AlGaAs/InGaAs sub-micron T-shape gate HEMTs by buried-Pt technique. The 0.2 µm gate length E-mode and D-mode AlGaAs/InGaAs HEMTs were developed and characterized. The dc, rf, and microwave power performance of the device will be presented. Furthermore, the E/D-Mode circuit was demonstrated, including inverter and differential amplifier.
