Reliability aspects of thermally stable LaB/sub 6/-Au Schottky contacts to GaAs

A systematic investigation of the reliability and the possible degradation mechanisms of Au-LaB/sub 6/ Schottky contacts to GaAs is presented. Due to a relatively large barrier height ( approximately=0.9 eV) LaB/sub 6/ Schottky contacts are particularly interesting for low leakage current device operation, even at elevated temperatures. The high thermal stability enables sophisticated fabrication processes in connection with ion implantation. The dependence of the contact reliability on certain annealing and processing techniques during device fabrication is demonstrated. Accelerated lifetime tests, in combination with electrical measurements and X-ray photoelectron spectroscopy (XPS) sputter profiling, have been performed, indicating that optimized technological parameters yield reliable contacts with good electrical characteristics.<
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