Investigation of electrical characteristics of (aAl-TiW+PtSi)/n-Si Schottky diodes depending on frequency and illumination

In this study, (Al-TiW+PtSi)/n-Si Schottky diodes were fabricated by a magnetrons sputtering method and their current-voltage (I-V) and admittance-voltage (C-V, G/w-V) measurements were carried out in dark and under illumination. The values of saturation current (Io), zero-bias barrier height (Bo), ideality factor (n) and series resistance (Rs) are found equal to 4,2x10-10A, 0,755 eV, 1,24 and 896 in the dark and to 7,47x10-10A, 0,740 eV, 1,18 and 419,7 W under illumination, respectively. In addition to this, the break down voltage of the (Al-TiW+PtSi)/n-Si Schottky is found to be near 21 V. The illumination process causes shift the capacitance-voltage (C-V) and conductance-voltage (G / -V) curves toward reverse bias about 150 mV and increases with increasing illumination level. This behavior can be explained by the built-up of fixed charge between metal and semiconductor attributed to changes in the number of interface states (Nss) due to the illumination process. In addition to these, the series resistance (Rs) of diodes can significantly alter the capacitance-voltage (C-V) and conductance-voltage (G/-V) characteristics and decrease with increasing illumination level. I-V characteristics have not ideal behavior and ideality factor (n) is controlled by the Nss in equilibrium with the semiconductor.