Characterization of the junction capacitance in metal-semiconductor interface states

摘要

In this study, the Cu/p-Si Schottky contacts were fabricated in the condensed matter physics Research Laboratory of Physics Department of Yuzuncu Yil University. The contacts were named as diode 1, diode 2, diode 3 and diode 4 diodes. The current-voltage (I-V), capacitance voltage (C-V) and capacitance-frequency (C-f) measurements of the samples were carried out in the same laboratory mentioned above in the dark and ambient temperature. The values of the ideality factor (n) and barrier height were calculated by using forward bias I-V characteristics. To check the accuracy of the calculated values the calculations were repeated by using Cheung's Functions. In addition, the values of the series resistance were also estimated by using Cheungs' Functions. The situation that the values of the ideality factor (n) were determined as to be greater than 1 was attributed interface layer and interface states. From the C-f plots, the capacitance values decrease with increasing frequency was observed. At the low frequencies, high capacitance values observed from C-f plots point out excess capacitance resulted from interface states. On the other hand, at the high frequencies, low capacitance values observed from C-f plots can be attributed the interface states cannot follow ac signals at high frequencies.