We report the design and fabrication of an InP MESFET with excellent I-V characteristics. We measured a record high transconductance of 110 mS/mm for a 1-Am gate length direct-Schottky-contact InP MESFET, where the InP surface was not passivated or treated prior to the deposition of the gate contact. Microwave measurements show an fmaxof 11.6 GHz for this typical nominal l-μm gate length device. A p-type planar doped layer was inserted between the buried n-type channel and the device surface at 18 nm from the gate metal. This planar layer enhances the Schottky barrier height and device performance.
Bibliographical noteFunding Information:
Manuscript received October 30, 1990; revised February 12, 1991. This work was supported in part by RADC, Solid State Electronics, Hanscom AFB, MA, NSF Equipment under Grant ECS-8806244, and the University of Minnesota Microelectronics and Sciences Center. The authors are with the Department of Electrical Engineering, University of Minnesota, Minneapolis, MN 55455. IEEE Log Number 9100354.