Static simulation of pseudomorphic heterostructure FETs at medium/high temperatures

Abstract

The drain current in a pseudomorphic heterostructure FET (P-HFET) has a negative temperature dependence which is correctly predicted when the electron transport through the barriers is taken into account. In order to compare simulation with experimental results, the static output characteristics on a long gate P-HFET have been measured over the temperature range 260-380 K. Hall mobility measurements at different temperatures and gate bias are included in the simulations. The static characteristics are simulated using a thermlonic field emission model that calculates the current across the Al0.3Ga0.7As/In0.3Ga0.7As heterojunction, where the effective band discontinuity is controlled by means of a parameter called effective length, l(ef). In this paper the use of l(ef) as a fitting parameter for the static characteristic curves is investigated.