High breakdown voltage AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistor with TiO2/SiN gate insulator

We report the fabrication of an AlGaN/GaN high-electron-mobility transistor (HEMT) with a high breakdown voltage by employing a metal-insulator-semi conductor (MIS) gate structure using TiO2/SiN insulators. We employed the TiO2/SiN gate insulator for the first time in a multilayered insulator structure MIS-HEMT. The gate leakage current was significantly reduced by employing the MIS structure, and the breakdown voltage characteristics of the fabricated MIS-HEMTs were 1.1 kV with an on-resistance of 15 m Omega cm(2) for a gate-drain length of L-gd = 28 gm. The current collapse in the TiO2/SiN MIS-HEMT has been improved by employing a thin SiN film under the TiO2 insulator. AlGaN/GaN MIS-HEMTs are promising not only for high-speed applications but also for high-power switching applications.