Near Room-Temperature Liquid-Phase Deposition of Barium-doped TiO_2 on n-GaN and Its Application to AlGaN/GaN MOSHEMTs

摘要

Barium-doped TiO_2 films deposited on GaN layers at low temperature through a simple liquid-phase deposition method is investigated. The use as a gate dielectric in AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistors (MOSHEMTs) is also demonstrated. The electrical characteristics of the metal-oxide-semiconductor (MOS) structure on n-doped GaN show that the leakage current density is about 5.09 × 10~(-9) A/cm~2 at 1 MV/cm, and the breakdown field is more than 13 MV/cm. The maximum drain current density of the AlGaN/GaN MOSHEMTs is higher than that of HEMTs, in which a wider gate voltage swing, a lower sub-threshold swing (112mV/dec), and a higher I_(ON)/I_(OFF) ratio (4.5×10~5) are obtained.