SrSnO₃Field-Effect Transistors with Recessed Gate Electrodes

Fabrication of gate-recessed SrSnO3 (SSO) metal-semiconductor field-effect transistors (MESFETs) with Ni Schottky gates is reported on bi-layer epitaxial SSO films with a thin heavily-doped cap layer. Devices with 0.5-μm gate length showed enhancement-mode behavior with a saturation drain current, IDSAT , of 33 mA/mm and peak transconductance, gm,max , of 65 mS/mm. The gm,max value is a roughly × improvement over control devices fabricated on single-layer films. Gate-recessed SSO MESFETs with Pt Schottky gates were also explored on the bi-layer films. Devices with 1-μm gate length displayed IDSAT =133 mA/mm and gm,max =73 mS/mm, after thermal annealing.