Enhancement Mode Ga2O3 Field Effect Transistor with Local Thinning Channel Layer

Abstract

β−Ga2O3 field−effect transistors (FETs) were fabricated with and without local thinning to change the threshold voltage. A 220 nm Ga2O3 layer was mechanically exfoliated from a Cr−doped gallium oxide single crystal. Approximately 45 nm Ga2O3 was etched by inductively coupled plasma to form the local thinning. The threshold voltage of the device with etched local thinning increased from −3 V to +7 V compared to the unetched device. The effect of the local thinning was analyzed by device simulation, confirming that the local thinning structure is an effective method to enable enhancement−mode Ga2O3 FETs.

β-Ga2O3 MOSFETs electrical characteristic study of various etching depths grown on sapphire substrate by MOCVD

“…Regarding the above methods, Ga 2 O 3 epilayers grown on native substrate generally demonstrated low breakdown voltages. Elsewhere, mechanically exfoliated Cr-doped Ga 2 O 3 substrates were utilized and transferred onto SiO 2 /Si substrate and then locally thinned to obtain E-mode MOSFETs [ 18 ]. Even though I D was very low it is not feasible to mass-produce devices using exfoliation methods.…”