Study of Schottky barrier formation in InP(110) by photoreflectance

摘要

The effects of using different p-InP(110) surfaces (air exposed,metal covered, and annealed) on the surface Fermi level position arestudied by photoreflectance (PR). Measurements are performed on the(110) atomic clean surface under ultrahigh vacuum conditions in amolecular beam epitaxy chamber. The built-in electric field, which isassociated with the barrier height, at the surface and/or metal/InPinterface is evaluated from the Franz-Keldysh oscillations exhibited inthe PR spectra. Schottky barrier heights of 0.21±0.02 eV for anatomically clean surface, 0.47±0.03 eV for an air exposedsurface, and 0.82±0.05 eV for a surface annealed at 350° C arefound. In addition, the Schottky barrier heights for the Ag/p-InP(110)and Au/InP(110) interfaces are found to be almost identical(0.43±0.04 eV and 0.47±0.03 eV, respectively), while forAl/p-InP(110) the barrier height is 0.60±0.04 eV