EFFECTS OF THERMAL EXPANSION COEFFICIENT MISMATCH ON STRUCTURE AND ELECTRICAL PROPERTIES OF TiO2 FILM DEPOSITED ON Si SUBSTRATE

Effects of thermal expansion coefficient (CTE) mismatch on structure and electrical properties of TiO2 film deposited on Si substrate by ion beam assistant electron beam evaporation have been investigated. Because of a high CTE mismatch between TiO2 film and Si substrate, microcracks appeared in the TiO2 film deposited directly on Si substrate after the as-deposited film was annealed at 600°C. In order to decrease the CTE mismatch, TiO2 film was deposited on Si substrate which was covered by a ZrO2 thin layer. As a result, crack–free TiO2 film after annealed at the same temperature was obtained. Meanwhile, corresponding to the crack–free structure, the TiO2 thin film has more stable dielectric properties and excellent I–V characteristics.