Analysis of parallel Schottky contacts by differential internal photoemission spectroscopy

Abstract

A differential analysis of internal photoemission spectroscopy has been developed for the study of nonuniformity in a Schottky contact. The analysis is capable of revealing the presence of a high-low parallel contact in a spectroscopic manner. It has been applied to a discrete parallel contact consisting of Pd2Si and NiSi as well as a nonuniform contact of Pd on Si in the as-deposited state. The nonuniformity in the latter case is due to the existence of high barrier regions (0.86 eV) in parallel to those of Pd 2Si (0.74 eV) and it disappears after a subsequent annealing at 250 or 450°C.