Nonlinear source resistance in high-voltage microwave AlGaN/GaN HFETs

• Published in: IEEE transactions on microwave theory and techniques Vol. 54; no. 5; pp. 2061 - 2067
• Main Authors: Trew, R.J., Yueying Liu, Bilbro, L., Weiwei Kuang, Vetury, R., Shealy, J.B.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AlGaN/GaN heterostructure field-effect transistors (HFETs); Aluminum gallium nitride; Amplifiers; Applied sciences; Circuit properties; Devices; Drains; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; FETs; Gallium nitride; GaN; HEMTs; large-signal operation; Microwave and submillimeter wave devices, electron transfer devices; Microwave devices; Microwaves; MODFETs; nonlinear source resistance; Nonlinearity; Power generation; Radio frequencies; Radio frequency; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Simulation; Transistors; Voltage; Wide band gap semiconductors; Performance evaluation; Microwave field effect transistors; Output power; AlGaN/GaN heterostructure field-effect transistors (HFETs); Large signal behavior; nonlinear source resistance; large-signal operation; Amplifier; Field effect transistor; Space charge limited conduction; High power; High voltage; Direct current; GaN; Linearity; Drain voltage; Heterojunction field effect transistor; Wide band gap semiconductors; Simulator; Electrical characteristic
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2006.873627

Wide bandgap semiconductors are used to fabricate field-effect transistors with significantly improved RF output power compared to GaAs- and InP-based devices. Nitride-based heterostructure field-effect transistors can be biased at high drain voltages, up to and exceeding 100 V, which results in high RF output power. However, the operation of these devices at high drain bias introduces physical phenomena within the device that affect both dc and RF performance. In this study, the existence of a nonlinear source resistance due to space-charge limited current conditions is demonstrated and verified. Inclusion of the nonlinear source resistance in a physics-based device simulator produces excellent agreement between simulated and measured data. The nonlinear source resistance degrades RF performance and limits amplifier linearity.