A microwave Schottky-barrier varistor using gallium arsenide for low series resistance

Microwave communications systems require varistors for downconversion, limiting and detection. This paper describes the development of a device being manufactured for these uses in the common carrier bands at 4, 6, and 11 GHz. The barrier-forming metals are titanium and silver on n-type epitaxial gallium arsenide. Means of characterization and control of the required doping profile in the 0.5 µm-thick epitaxy will be discussed. Plated gold contacts overlaying deposited silicon dioxide are used with a miniature cartridge encapsulation.