Silicon Substrate Engineered High-Voltage High-Temperature GaN-DHFETs

• Published in: IEEE transactions on electron devices Vol. 60; no. 7; pp. 2217 - 2223
• Main Authors: Srivastava, P., Das, J., Mertens, R. P., Borghs, G.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-07-2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AlGaN/GaN/AlGaN; Applied sciences; breakdown voltage; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; double-heterostructure FETs (DHFETs); Electronics; Exact sciences and technology; Gallium nitride; Hall measurement; III-V semiconductor materials; Leakage currents; local Si substrate removal; Materials science; metal-organic chemical vapor deposition (MOCVD); Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Substrates; Temperature; Temperature measurement; Transistors; Ternary compound; Binary compound; High temperature; AlGaN/GaN/AlGaN; Gallium nitride; Degradation; Low voltage; Microelectronic fabrication; Disruptive voltage; breakdown voltage; double-heterostructure FETs (DHFETs); Silicon; local Si substrate removal; metal-organic chemical vapor deposition (MOCVD); Hall measurement; Cost lowering; Thermal conduction; Damaging; Aluminium nitride; Electrical conduction; Buffer system; Chemical vapor deposition; MOCVD; III-V compound; Temperature coefficient; High voltage; Parasitic resistance; Leakage current; Heterojunction field effect transistor; Room temperature; On off effect
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2013.2263253

Low-cost GaN-on-Si-based transistors are targeted to function at high ambient temperatures. With this perspective, it is aimed to evaluate the high-temperature (HT) capabilities of GaN-on-Si double-heterostructure field-effect transistors. It is highlighted that HT device operation degrades both ON and OFF states that are directly related to the increase in the on-resistance and the decrease in device breakdown voltage; 2-DEG mobility drops with increasing temperature and is responsible for ON-state degradation. Regarding the OFF-state operation, it is observed that at low-voltage operation and with increasing temperature, there is an increase in the OFF-state leakage current because of thermal-assisted electrical conduction across the III-N layers and various interfaces. The main breakdown limiting mechanism at any temperature is, however, buffer leakage along the AlN/Si interface. Because this parasitic conduction, a negative temperature coefficient of breakdown voltage of approximately -1 V/°C is observed. For devices after Si removal, the leakage across the AlN/Si interface is interrupted and therefore HT OFF-state characteristics show high potential to be used at high operating voltage. A breakdown voltage as high as ~1800V is observed after Si removal compared with ~500 V with Si at 150°C.