BARRIER HEIGHT OF INP SCHOTTKY DIODES PREPARED BY MEANS OF UV OXIDATION

Schottky diodes of Au/oxide/InP are fabricated by means of UV oxidation and evaluated by means of current-voltage (I-V) and capacitance-voltage (C-V) measurements. Their barrier heights are estimated from the I-V curve at room temperature, the 1/C2-V plot and the Richardson plot. Remarkable apparent improvement of the I-V characteristics is achieved with the use of UV oxidation. However, there is a discrepancy among the barrier heights calculated from the three characteristics. It is revealed that these results are caused by the reduction in the saturation current due to electron tunneling through the UV oxide layer. On the basis of a tunneling model, the relationship between the tunneling probability and the thickness of the oxide is discussed.