Title :
High voltage operation in class B GaAs X-band power MESFETs
Author :
Sriram, S. ; Clarke, R.C. ; Messham, R.L. ; Smith, T.J. ; Driver, M.C.
Author_Institution :
Westinghouse Sci. & Technol. Center, Pittsburgh, PA, USA
Abstract :
Surface trapping effects are shown to affect adversely the RF power performance of high-voltage GaAs MESFETs and a model is presented to explain them. It is shown that the adverse effects of surface trapping can be minimized by: (1) including an undoped layer near the surface, (2) reducing the distance between the gate and n+ ledge, and (3) making the gate recess narrower than the gate. Devices fabricated with such a structure showed excellent RF power performance at 10 GHz: P0=678 mW/mm, G A=6.8 dB, and ηPA=51.1% at a drain-bias voltage of 12 V. The design of devices to minimize surface-trapping effects is also expected to lead to self-passivating devices that will be inherently more reliable and show less 1/f noise. The high-voltage, high-efficiency devices described here will be applicable in airborne phased array radar systems where power supply requirements and heat dissipation problems limit system performance
Keywords :
III-V semiconductors; Schottky gate field effect transistors; gallium arsenide; power transistors; semiconductor device models; solid-state microwave devices; 10 GHz; 12 V; 51.1 percent; 6.8 dB; GaAs; RF power performance; SHF; X-band; class B; drain-bias voltage; gate recess narrower; high voltage operation; high-efficiency devices; less 1/f noise; minimize surface-trapping effects; model; power MESFETs; self-passivating devices; semiconductors; surface trapping; undoped layer; Airborne radar; Gallium arsenide; MESFETs; Phased arrays; Power supplies; Power system reliability; Radio frequency; System performance; Time of arrival estimation; Voltage;
Conference_Titel :
High Speed Semiconductor Devices and Circuits, 1989. Proceedings., IEEE/Cornell Conference on Advanced Concepts in
Conference_Location :
Ithaca, NY
DOI :
10.1109/CORNEL.1989.79838
