Development of III-nitride transistors: heterojunction bipolar transistors and field-effect transistors

III-nitride;Heterojunction;Bipolar transistor;Field-effect transistor;Fabrication process

Lee, Yi-Che ; Shen, Shyh-Chiang Electrical and Computer Engineering Dupuis, Russell D. Yoder, Paul Douglas Doolittle, William Alan Jiang, Zhigang ; Shen, Shyh-Chiang

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: III-nitride;    Heterojunction;    Bipolar transistor;    Field-effect transistor;    Fabrication process;   

Others  :  https://smartech.gatech.edu/bitstream/1853/53472/1/LEE-DISSERTATION-2015.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

The fabrication processes development for on III-nitride (III-N) heterojunction bipolar transistors (HBTs), heterojunction field-effect transistors (HFETs) and metal-insulator-semiconductor field-effect transistors (MISFETs) were performed. D.c, microwave and quasi-static I-V and C-V measurements were carried out to characterize the fabricated III-N transistors and diodes. The GaN/InGaN direct-growth HBTs (DG-HBTs) grown on free-standing GaN (FS-GaN) substrates demonstrated a high current gain (hfe) > 110, high current density (JC) > 141 kA/cm2, and high power density (Pdc) > 3 MW/cm2. The first III-N DG-HBT showing fT > 8 GHz and fmax > 1.3 GHz were also demonstrated on sapphire substrates. Recessed-gate AlGaN/AlN/GaN HFETs demonstrated Vth = 0 V with 0.17 V deviation across the sample. Baliga's figure of merit is 240 MW/cm2 was achieved. Current collapse was eliminated and the dynamic on-resistance was reduced by 67% after using a remote-oxygen-plasma treatment. Normally-off recessed-gate AlGaN/AlN/GaN MISFETs with Vth = 0.9 V were also fabricated with the remote-oxygen-plasma treatment. Low leakage current (< 1 pA/mm), high on-off ratio (> 2.2E11) are achieved. These achievements suggest that high-performance III-N transistors are very promising for high-power switching and microwave amplification. Findings concerning remaining process issues and implications for future research are also discussed.