GaAs(110) -Al INTERFACES FORMED AT LOW TEMPERATURE

Abstract
We report the first characterization of Al layers deposited on low temperature (100°K) cleaved GaAs(110). The surface mobility of Al is considerably reduced as the temperature is lowered, in agreement with estimates of Al hopping frequency at the surface of GaAs(110). Reduction in mobility leads to more homogeneous Al layers. Changes in the atomic geometry of the interface are detected with LEED. A preliminary analysis of the LEED data suggests that the GaAs(110) surface is unrelaxed by Al. Contact potential difference measurements of the evolution of the work function vs. Al coverage indicate the formation of an Al-surface dipole which is much larger than at room temperature