Detailed analysis of quasi-ohmic contacts to high resistive GaAs:Cr structures

Proper choice of a contact material leads to the reduction of leakage current, an increase of X-ray penetration coefficient when so-called transparent contacts are used, and an increase of the Signal-to-Noise ratio. This work is dedicated to the investigation of quasi-ohmic contact behaviour in the "Me-GaAs:Cr-Me" system. AuGe contact was made by means of electron-beam deposition as a metallization layer (Me) to form the "Me-GaAs:Cr-Me" system. Chromium compensated GaAs samples of different thicknesses in the range of 250–1000 μm were tested. The investigation was carried out under various temperature conditions. The results of current-voltage dependence measurement give an overview of the current transport model in such structures and allow us to calculate the concentration of deep-level impurities.