Demonstration of a Depletion-Mode SrSnO3 n-Channel MESFET

The demonstration of SrSnO3 metal-semiconductor field effect transistors (MESFETs) is reported. The device layer structure consists a 28-nm-thick n-type SrSnO3 film on top of an 11-nm-thick undoped SrSnO3 film grown by hybrid molecular beam epitaxy on a (110) GdScO3 substrate. The MESFETs utilize a Pt Schottky gate electrode and diffused Sc Ohmic contacts. A Schottky barrier height of 1.55 eV was extracted for Pt on SrSnO3 using capacitance-voltage measurements. Devices with a gate length of 3 mu m and source-drain spacing of 9 mu m had a drive current of 36 mA/mm at V-GS = +1 V and V-DS = +3.5 V, and a peak extrinsic (intrinsic) transconductance of 17 mS/mm (35 mS/mm).