Probing island growth and coalescence at metal-semiconductor interfaces

Synchrotron-radiation photoemission spectroscopy of Xe atoms physisorbed on metal-semiconductor interfaces at different stages of interface formation allowed us to detect the presence of metal islands, determine the local work function of the islands and of the semiconductor surface between the islands, gauge the coverage dependence of the island size, and measure the coalescence coverage. This technique is a nondestructive, nonperturbative local probe of nucleation and growth with high spatial resolution and unparalleled surface sensitivity. We present detailed results for Yb-Hg1-xCdxTe(110) and preliminary results for K-GaAs(110).