AlGaN/GaN metal oxide semiconductor high electron mobility transistor using liquid-phase deposited strontium titanate

Abstract: SrTiO3 thin films were deposited on AlGaN/GaN wafer by a simple, low-temperature liquid-phase deposition (LPD) method, and applied as the gate dielectric in metal oxide semiconductor high electron mobility transistor (MOSHEMT). X-ray diffraction and electrical characteristics were measured to investigate the film phase and leakage current. AlGaN/GaN MOSHEMTs with 20nm-thick SrTiO3 as the gate dielectric were also fabricated. Compared with its counterpart HEMT, MOSHEMT shows lower leakage current and larger breakdown voltage. The suppressed gate leakage current improves both I on/I off ratio and subthreshold slope. Larger maximum drain current density could be achieved with higher V on in the MOSHEMT. Flatter transconductance and wider gate voltage swing of the MOSHEMT demonstrate better device linearity. The lower low-frequency noise is obtained due to the lower surface states. [Copyright &y& Elsevier]