Effect of gamma radiation on current-voltage characteristics in Au/SnO2/n-Si/Au schottky diodes

In this thesis, an Au/SnO2/n-Si Schottky structure was obtained by growing the tin oxide (SnO2) layer between metal-semiconductor by sputtering method. The currentvoltage (I-V) measurements of the Schottky diode structure were taken before and after radiation. The produced diode was exposed to 10 kGy 60 Co gamma rays. Diode parameters such as pre- and post-radiation saturation current (I0), ideality factor (n), barrier height (ΦB), series resistance (Rs) and interface state density (NSS) were calculated using thermionic emission theory. The calculated parameters I0, n, ΦB were calculated as 2.33x10-6 A, 3.49, 0.627 eV at 0 kGy, and 2.70x10-7 A, 2.45 and 0.683 eV at 10 kGy, respectively. It was observed that the barrier height increased while the ideality factor decreased after radiation. The series resistance was calculated using the Cheung and Norde methods. By Norde method, Rs and ΦB values were found as 1.37 kΩ and 0.641 eV at 0 kGy, 2.20 kΩ and 0.686 eV at 10 kGy, respectively. It was observed that the series resistance value increased after radiation. The interfacial state density (NSS) before and after radiation was determined in the EC-ESS energy range. These values for 0 kGy before irradiation were observed to decrease from 4.14x1012 cm-2 eV-1 at EC-0.498 eV, to 7.56x1011 cm- 2 eV-1 at EC-0.606 eV after irradiation, NSS values decreased from 2.84x1012 cm-2 eV- 1 at EC-0.496 eV and 4.10x1011 cm-2 eV-1 at EC-0.610 eV at 10 kGy.