Depletion Capacitance and Diffusion Potential of Gallium Phosphide Schottky‐Barrier Diodes

摘要

The diffusion potential VBO and the intercept V0 of the 1/C2 vs bias plots for n‐type GaP‐metal Schottky‐Barrier diodes have been measured. Photoresponse measurements indicate that VBO is not sensitive to the thickness δ of the interfacial separation between the GaP and the metal; V0 is observed to increase rapidly with δ. The 1/C2 plots are linear in all cases, with slopes independent of V0. The values for the donor density ND, calculated in the usual way from slopes of the 1/C2 plots, seem to agree within experimental error with ND calculated from the resistivity of the GaP. Several models are proposed for the metal‐interfacial‐layer‐semiconductor system in order to explain this behavior. The GaP‐metal diodes are shown to be best characterized by a model which includes a bias‐dependent charge in surface states at the semiconductor surface.