PHOTOLUMINESCENCE CHARACTERIZATION OF STRUCTURES OBTAINED BY MULTIPOLAR PLASMA OXIDATION OF INP

The dependence on bias of the photoluminescence (PL) intensity of Schottky diodes and oxidized structures obtained by multipolar plasma oxidation of n-InP was compared. For the oxidized structures, the calculated PL intensity curve remained well below the experimental results. This fact is attributed to a limited swing of the surface Fermi level of the semiconductor. The flat band voltage was also deduced from PL measurements, and the corresponding barrier height phi(B) = 0.4 eV is in good agreement with the value inferred from current-voltage results for the Schottky diode. For the oxidized structures there was a difference in phi(B) deduced using the two methods. The presence of the thin oxide layer must at least be considered to explain these different apparent barrier heights.