Study of submicron InP transferred electron devices

Abstract

We have performed an experimental and numerical investigation of near-micron, and a numerical investigation of submicron sized InP transferred electron devices (TEDs) having alloyed metal cathode ‘‘current-limiting’’ contacts. A drift and diffusion analysis utilizing a modified Schottky barrier for the cathode contact was used to model the dc characteristics of near-micron structures, while a Boltzmann transport equation moments analysis with a cathode mobility model was implemented in order to simulate the ac and dc results in general. Our theoretical study emphasized the length effect for submicron structures. A generalized ‘‘different areas rule’’ for short devices was compared with the results of our numerical analysis. Submicron InP TEDs were studied and simulated numerically in the near millimeter wave region (100–250 GHz). The static velocity-field, v(E), characteristics showed a large deviation from long device behavior (≳1.0 μm) as the device length decreased into the submicron region. The upper limit for the transit-time frequency was predicted numerically to be about 230 GHz for a 0.2-μm InP TED. The interrelated controlling parameters: device length, bias, boundary conditions, doping density, were investigated in the numerical analysis and utilized to set design rules.