Measurement and modulation of atomic interdiffusion at Au–Al/GaAs(110) interfaces

Atomic layers of Al at Au‐GaAs(110) interfaces have been used to measure the absolute motion of metal and semiconductor atoms at their intimate contact. This new technique reveals both Au indiffusion and nonstoichiometric outdiffusion during the initial stages of Schottky barrier formation. The Al ’’interlayers’’ at Au–GaAs interfaces also modulate the relative Ga to As diffusion into Au by over an order of magnitude. This new phenomenon at compound semiconductor–metal interfaces reveals a systematic relationship between the local atomic bonding and the extended chemical structure of the interface.