Investigation of the effect of dielectric thin films on si photodetector device performance

This work contains the investigation of dielectric films effect on photoresponse and dark current in Silicon-based photodetectors. Computer-aided models were created using Silvaco software and parametric simulations were performed. Anti-reflection values were calculated for the dielectrics to increase the detector photo response performance. Considering the compatibility with Silicon, the most successful anti-reflection performance was obtained from Si3N4 thin film with refractive index of 1.87. Passivation performances were investigated by measuring the charge density at the dielectric-semiconductor interface. Simulations have been made for capacitance-voltage measurements and theoretical ground has been established before experimental studies. The passivation performances of SiO2 thin films grown by methods such as wet thermal oxidation, PECVD and gettering dry thermal oxidation were compared with photoconductivity and capacitance measurement results. It has been observed that SiO2 thin films grown by the gettering dry oxidation technique provide the most successful passivation for Silicon-based devices.