FABRICATION AND CHARACTERIZATION OF Au/MO/n-Si (MO: ZnO, In2O3, Al2O3) SCHOTTKY DIODES GROWN BY RF MAGNETRON SPUTTERING

In this study, for investigating the effects of ZnO, In2O3 and Al2O3 interfacial layer, three types of Schottky diodes were fabricated by radio frequency (RF) magnetron sputtering method on the identical n-Si substrate with the same rectifier and ohmic contacts. The main diode parameters of them were determined from the current-voltage (I-V) characteristics at room temperature and compared in detail. The analysis of I-V plot showed a non-ideal diode behavior according to the thermionic emission technique due to the existence of interfacestates, interfacial layer, and series resistance. The measured values of I-V for all samples were utilized to compute the ideality factor (n), barrier height (Phi(b)), series resistance (R-s) and interface state density (N-ss) values. The values of n and Phi(b) of Au/ZnO/n-Si (SD1), Au/In2O3/n-Si (SD2) and Au/Al2O3/n-Si (SD3) Schottky diodes were calculated to be 2.05-0.707 eV, 2.19-0.675 eV and 1.23-0.773 eV, respectively. The lowest values of ideality factor, series resistance and density of interfacial states were obtained in Au/Al2O3/n-Si Schottky diode. These results show that the used the Al2O3 interlayer used in the Au/n-Si interface improves the performance of the metal-semiconductor diode rather than other metal oxides.