Channel temperature measurements of InxAl1−xN/GaN high electron mobility transistors on Si(111) using optical spectroscopy

• Published in: Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2015-09, Vol.33 (5)
• Main Authors: Kyaw, Lwin Min, Bera, Lakshmi Kanta, Bhat, Thirumaleshwara N., Liu, Yi, Tan, Hui Ru, Dolmanan, Surani Bin, Chor, Eng Fong, Tripathy, Sudhiranjan
• Format: Article
• Language: English
• ISSN: 2166-2746; 2166-2754
• DOI: 10.1116/1.4927366

The temperature profiles of InxAl1−xN/GaN high electron mobility transistors (HEMTs) were investigated using nondestructive optical spectroscopic techniques. In this study, HEMT structures were epitaxially grown on a Si(111) substrate with a diameter of 200 mm. In particular, the channel temperature underneath the gate was able to be accurately probed by using a RuOx-based semitransparent Schottky contact in the ultraviolet photoluminescence (PL) and visible Raman excitation modes. A maximum channel temperature as high as ∼475 K was probed near the gate edge using the PL technique at a power dissipation of ∼11.6 W/mm, thus leading to a minimum thermal conductance of about 64.7 Wm−1K−1 in such a HEMT structure. Furthermore, the temperature profiles at the GaN buffer and AlN/Si(111) interface were determined using micro-Raman measurements.