Study of Al/Pd₂Si contacts on Si

An electrical and structural characterization of the Al/Pd2Si thin‐film system on n‐type Si was performed with the use of Schottky barrier contacts and subsequent heat‐treatment cycles. Contact barrier energy φBn, as extracted from current–voltage and capacitance–voltage measurements, decreased initially from about 0.71 eV, characteristic of the Pd2Si interface, to a value of 0.65 eV. Auger electron spectroscopy analysis indicates the observed decrease in φBn corresponds to the decomposition of the Pd2Si layer. A drastic alteration of the diode morphology accompanied the decrease in φBn. Successive heat treatments at higher temperatures and longer times produced little subsequent change in the structural form of the surface, but yielded an increase in φBn to a value greater than 0.81 eV. Additional data indicated that Al may enter the n‐type Si as a compensating impurity during prolonged heat treatments.