TiO2 and GaN thin film were successfully fabricated on Si substrate by a sol-gel method. However, thin films did not show crystallinity structure without any treatment. To increase the crystallinity of thin films, TiO2 thin films were annealed while GaN was annealed under NH3 gas flow. The annealing temperature range was 700~900°C, and the effects of thermal effect on the structural and electrical properties of TiO2 and GaN films were studied. The resulting films show high crystallinity as indicated via the XRD analysis. As annealing temperature increases up to 900°C, the grain size and the surface roughness increases. Sol-gel thin film driven Schottky diodes are fabricated with Si and Al electrodes, and characterized by measuring their current-voltage behavior with -2~2 V range. TiO2 and GaN Schottky diode with high crytallinity structure show a high forward current.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.