ELECTROCHEMICALLY FABRICATED HIGH-BARRIER SCHOTTKY CONTACTS ON N-INP AND THEIR APPLICATION FOR METAL-SEMICONDUCTOR-METAL PHOTODETECTORS

The results of a study of electrochemically fabricated Pt/n-InP Schott ky contacts and the feasibility of the process for InP-based metal-sem iconductor-metal photodetectors are reported in the present paper. The electrochemical process yields a significant improvement of Schottky- barrier properties. This is mainly attributed to two advantages of the process: first, the in situ etching of the semiconductor surface just prior to Schottky contact formation and second, the damage-free metal lization. The ideality factor and barrier height obtained for the Pt/n -InP Schottky contacts are 1.03 and 0.65 eV; respectively A damage-fre e Pt/InP interface is revealed by the deep-level transient spectroscop y spectrum. The x-ray photoelectron spectroscopy sputter-profile of th e electrochemically fabricated Pt/InP is presented. The metal-semicond uctor-metal photodetector structures of an active area of n-InP, 100 x 100 mu m fabricated by the same process, show a dark current df 10 nA and a capacitance of 0.65 pF at a 5 V bias.