Realization of a resonant tunneling permeable base transistor with optimized overgrown GaAs interfaces

A resonant tunneling permeable base transistor has been realized experimentally by overgrowing a tungsten grating placed in direct vicinity to a double barrier heterostructure. In this way, we can directly modulate the tunneling current via an embedded gate. Since the quality of the overgrown interface is critical, special attention is paid to this issue, and the effect of different wet etchants prior to overgrowth is studied both by electrical measurements and by the use of an atomic force microscope. A clear dependence of the electrical properties and the crystal quality on the etchants used is found. This is a key result for the realization of our resonant tunneling device.