Electrical properties of Au/GaAs Schottky contacts fabricated by electron-beam (EB) evaporation were characterized by current-voltage (I-V), capacitance-voltage (C-V) and photoresponse (PR) measurements. Resistance-heated (RH) evaporation and sputter (SP) deposition techniques were also used as references. For n-GaAs substrates, the barrier height became lower in order of RH, EB and SP, and vice versa for p-type substrates. Photoyield as well as depletion-layer width were also compared among the deposition techniques. We intepreted that the poor diode characteristics in EB as well as SP diodes were attributed by donor-type defects introduced on the GaAs surface during the metal deposition.
We manufactured an equipment for inverse photoemission spectroscopy (IPES) which directly gives the information on unfilled density of state of a surface. We estimated the calculated resolution of this equipment at 1.1 eV, whereas experimental resolution of about 1.3 eV was obtained from a Au spectrum. From this value, manufactured equipment seems to approximately satisfy the condition of design. Therefore, manufactured IPES are considered to be useful method for the investigation of the surface.