Suppression of short-channel effects in normally-off GaN MOSFETs with deep recessed-gate structures

Abstract

We have demonstrated the suppression of short-channel effects (SCEs) in normally-off GaN metal-oxide-semiconductor field-effect transistors (MOSFETs) with deep recessed-gate structures. TCAD simulation results show that the electric field concentration is effectively reduced at the recessed edge of MOSFETs with deeper recessed-gate structures. To demonstrate suppression of SCEs, MOSFET gate structures with recess depths ranging from 45 to 165 nm were fabricated and evaluated. Experimental results show that deeper recessed-gate structures are highly effective for suppressing drain-induced barrier lowering and improving subthreshold swing and threshold voltage roll-off.