Electronic properties of InAs(1 0 0) surface in relation to native oxide chemistry modified by X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) has been used extensively to characterize the surface chemistry of oxide-terminated III-V semiconductors. Herein, we show that during the continuous, uninterrupted acquisition of the photoelectron spectra of native oxide-terminated (1 0 0) indium arsenide (InAs) significant changes in both the surface chemical and electronic properties occur. Arsenic (As) oxidation states were reduced during the measurement, the initial native oxide chemical inhomogeneity with depth was significantly diminished, and the initial InAs band bending decreased by over a hundred meV. We find that the changes in the oxide overlayer chemistry are due to oxygen desorption induced by X-ray exposure in vacuum and a redistribution of coordinated oxygen atoms among different As oxidation bonding units. The evolution of the oxide overlayer is hypothesized to either reduce interface bond distortion, interface defects and donor-like state density or annihilate positive charges in the native oxide and interface electric fields, consistent with the observed decrease in the InAs surface band bending. Thus, our results show that the surface electronic properties of InAs are intimately coupled to the native oxide chemistry.

Duke Scholars

Author Charles Parker  

Author Jeffrey Glass Electrical and Computer Engineering

Author April S. Brown Electrical and Computer Engineering