Monte Carlo study of self-heating effect in GaN/AlGaN HEMTs on sapphire, SiC and Si substrates

• Published in: Physica status solidi. C Vol. 2; no. 7; pp. 2696 - 2699
• Main Authors: Fujishiro, H. I., Mikami, N., Hatakenaka, M.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2005; WILEY‐VCH Verlag
• Subjects: 02.70.Uu; 71.30.+h; 72.80.Ey; 73.40.Kp; 73.61.Ey; 85.30.Tv
• ISSN: 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200461342

A mechanism of self‐heating in GaN/AlGaN HEMT and an influence of lattice‐temperature rise on device performance are investigated theoretically. A novel simulation technique is applied, where a local temperature‐dependent carrier transport is calculated by employing a Monte Carlo (MC) particle technique in combination with a heat flow calculation. The devices on substrates of three different materials, i.e., sapphire, silicon carbide (SiC), and silicon (Si) are studied and compared. The heat generation concentrates on a drain side of area under a gate, which is mainly coming from intra‐valley scatterings of electrons in Γ1 and U valleys under a high electric field. It is suggested that the SiC and the Si substrates are of great advantage to reduction of the self‐heating effect on device performance because of their higher thermal conductivities, in comparison with the sapphire substrate. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)