Semiconductor functional device and electronic circuit provided with the

Abstract

A semiconductor functional device includes a semi-insulating semiconductor substrate; a resonant tunneling structure which includes, on the substrate, an n-type collector layer, an epitaxial multilayer structure including a double barrier structure constituted of a plurality of barrier layers holding a well layer therebetween, and an n-type emitter layer; an emitter electrode formed on the emitter layer; and a collector electrode formed on the collector layer. An undoped semiconductor barrier layer is interposed between the semi-insulating semiconductor substrate and the collector layer. With respect to a width of the emitter electrode, a thickness and an impurity concentration of the collector layer are selected such that the collector layer is pinched off when a potential difference generated between the emitter layer and the collector layer is equal to a valley voltage of I-V characteristics of the resonant tunneling structure constituted between the emitter layer and the collector layer while electrons travel from the emitter electrode toward the collector electrode through the emitter layer, the epitaxial multilayer structure and the collector layer. Consequently, the I-V characteristics have a single peak so as to satisfactorily suppress an increase in current if an applied voltage is higher than the valley voltage. Moreover, it is possible to achieve an electronic circuit provided with the semiconductor functional device having a large design margin and a large fabrication tolerance.