Dramatic improvements in AlGaN/GaN HEMT device isolation characteristics after UV-Ozone pretreatment

• Published in: Journal of the Electrochemical Society 2004, Vol.151 (12), p.G915-G918
• Main Authors: MOSER, N, FITCH, R. C, PEARTON, S. J, CRESPO, A, GILLESPIE, J. K, JESSEN, G. H, VIA, G. D, LUO, B, REN, F, GILA, B. P, ABERNATHY, C. R
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Electronics; Exact sciences and technology; Iii-v semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1803561

The effect of UV-ozone pretreatment of AlGaN/GaN high electron mobility transistor (HEMT) surfaces prior to SiNx passivation is reported. Without pretreatment, breakdown voltages dropped from 60 V (the test maximum) to ~5 V, and interdevice isolation current increased from 10-9 to 10-6 A following plasma-enhanced chemical vapor deposition SiNx passivation. With pretreatment, breakdown voltages dropped from 60 to ~58 V, and interdevice isolation current increased from 10-9 to ~10-8 A following SiNx passivation. Transmission electron microscopy and X-ray photoelectron spectroscopy measurements showed the formation of a 15-25 A thick GaO layer as a result of the UV-Ozone treatment. HEMT device results showed that UV-ozone pretreatment does not degrade the ability of the SiNs to provide effective surface passivation and reduce current collapse.