Permeable Base Transistors with Schottky and junction Gates

Permeable base transistors (PBT) with metal gates and pn-junction gates have been fabricated with conventional device technology. Measurement results compared with simulations are presented. Although the structures are not optimised, cutoff frequencies of 5.3 GHz for the PBT´s with pn-junctions are reached. The PBT´s with Schottky gates reach 7 GHz, however, with a lower breakdown voltage. A simple measure to increase the cutoff frequency with a factor two is proposed.