Planar doped barrier transferred electron oscillator

Abstract

A transferred electron semiconductor device in the form of an oscillator, for example, is fabricated by a molecular beam epitaxy growth process wherein a plurality of semiconductor layers are sequentially grown on a planar substrate. A pair of ohmic contacts are formed on the outer surface of the substrate and the uppermost layer with the resulting structure including two distinct intermediate semiconductor regions, the first being a drift region adapted to exhibit a differential negative resistance due to the transferred electron effect, and the second being a planar doped barrier region for accelerating electrons into the upper valley and injecting them into the drift region. By the use of a planar doped barrier a more uniform electric field is obtained along with a controlled lower barrier height whereby the transfer of electrons to the upper conduction band satellite valley can be made to occur over much shorter times and distances thus extending the upper frequency range of operation.