LAUSR

This letter demonstrates an integration process of in situ Cl^- doped Al₂O₃ and gate recess technique to fabricate the enhancement mode AlGaN/GaN MOSHEMTs. The Cl^- doped Al₂O₃ thin film is deposited by the ultrasonic spray pyrolysis deposition and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The relative permittivity of Cl^- doped Al₂O₃ is higher than the pure Al₂O₃ and the output current is enhanced. The threshold voltage of the enhancement mode AlGaN/GaN MOSHEMT with the Cl^- doped Al₂O₃ gate dielectric layer rose from 0.2 to 1.3 V. Furthermore, the breakdown voltage of present enhancement mode AlGaN/GaN MOSHEMT reached 650 V. It was also found that the MOSHEMT with Cl^- doped Al₂O₃ has higher gate leakage than that with pure Al₂O₃. The thermal stability of threshold voltage and current collapse phenomenon is described in this letter.