Improvements of electrical and thermal characteristics for AlGaN/GaN HEMT grown by metal-organic chemical vapor deposition on silicon-on-insulator (SOI) substrate

AlGaN/GaN high electron mobility transistors (HEMTs) heterostructures are grown by metal-organic chemical vapor deposition on silicon-on-insulator (SOI) substrate and high-resistivity silicon (HR-Si) simultaneously to investigate the influence of substrate types on electrical and thermal characteristics. The AlGaN/GaN HEMT epitaxial structure grown on SOI achieved high electron mobility (1900 +/- 19 cm(2) (V s)(-1)) and high two-dimensional electron gas carrier concentration (9.1 +/- 0.1 x 10(12) cm(-2)). The GaN HEMT metal-insulator-semiconductor gate device fabricated on the structure grown on the SOI substrate exhibits higher saturation current and improved buffer breakdown voltage compared with devices fabricated on HR-Si substrate. In particular, SOI substrate helps to improve the thermal-sensitive strain of the GaN-based heterostructure and reduced defect density in the epitaxy, thereby improve the temperature-dependent on-resistance (R (ON)) and the dynamic R (ON) of the device.