Effect of oxygen plasma treatment on the electrical characteristics of Pt/n-type Si Schottky diodes

Abstract

The electrical properties of Pt/n-type Si Schottky diodes fabricated from n-type Si wafers subjected to an oxygen (O2) plasma treatment were investigated as a function of the power of the O2 plasma. The Pt/n-type Si Schottky diode with an O2 plasma treatment at a power of 100 W showed better rectifying characteristics with increasing barrier height and decreasing ideality factor compared to the conventional Pt/n-type Si Schottky diodes. This could be attributed to an improvement in the interface homogeneity associated with damage-free surface smoothing driven by the O2 plasma treatment at a power of 100 W. On the other hand, with increasing power of the O2 plasma for powers above 150 W, the barrier height decreased and the leakage current increased, indicating degradation of the device performance. The degradation in the rectifying properties after the O2 plasma treatment at a higher plasma power in excess of 150 W could be associated with increases in the series resistance and the interface state density caused by plasma-induced damage to the Si surface.