Reliable, High Temperature Stable Schottk Contacts to GaAs Based on LaB6 Diffusion Barriers

The thermal stability of Au-LaB6 Schottky-diodes on n-GaAs has been investigated using I/V-measurements and XPS-analysis. The e-beam evaporated contact systems exhibit good electrical properties. It could be shown that the ideality factor and the barrier height improves after a certain annealing step and remains almost stable even after prolonged operation at 400°C. This demonstrates the suitability of lanthanum hexaboride to be used as a high temperature stable diffusion barrier in Au-LaB6 Schottky contacts to GaAs.