Soft X-ray photoemission characterization of the H2S exposed surface of p-InP

Synchrotron radiation soft x-ray photoemission spectroscopy was used to characterize the surface chemistry of p-InP before and after exposure to H2S gas at ambient temperature. The effect of the H2S dosing was determined by in situ photoemission measurements which were acquired after each gas exposure in order to observe changes in the valence band electronic structure as well as changes in the In 4d, P 2p, and S2p core lines. The results were used to correlate the surface chemistry to the electronic properties. These measurements indicate that the H2S exposure type converts the p-type InP surface to an n-type surface and that the magnitude of the band bending is 0.6 eV resulting in a homojunction interface.