Effect of hydrogenation on the properties of metal-GaAs Schottky barrier contacts

The effect of hydrogenation (incorporation of atomic hydrogen) on the prope rties of n-GaAs and the characteristics of Au-GaAs Schottky barrier contact s (the ideality factor of the current-voltage characteristic n, the barrier height phi(b), and the reverse voltage V-r at a current of 10 mu A) has be en investigated. The n-GaAs surface was bare (A-type samples) or was protec ted by an ultrathin (similar to 50 Angstrom) layer of SiO2 (B-type samples) during hydrogenation. It was shown that there was an optimal hydrogenation regime for the A-type samples (temperature range 150-250 degrees C and dur ation 5 min), for which n and V-r reached their minimum and maximum values, respectively. For the B-type samples, n and V-r improve starting from mini mal durations and temperatures of hydrogenation and remain constant or even improve over the entire investigated range of temperatures (100-400 degree s C) and durations (1-50 min). The donor impurity passivation processes are roughly the same for the A- and B-type samples. (C) 1998 American Institut e of Physics. [S1063-7826(98)01211-3].