Geometric Magnetoresistance (GMR) as a Tool for Characterizing InP Transferred Electron Devices

The GMR technique has been used to evaluate contact properties in completed InP transferred electron devices. Devices made on the same layer but with different contacts, Sn dot, Ag/Sn and Ag, have respectively displayed more enhanced Schottky barrier behaviour in their I-V characteristics and in GMR measurements as a function of bias, ¿(V). At room temperature a model involving a low height barrier, series resistance and a resistance in parallel with the barrier has been fitted to the measured I-V of an Ag/Sn contact device and the results used to correct the asymmetrical ¿(V) to give the bulk mobility variation.