The recrystallization and dielectric behavior for amorphous CaHfOx films on Si substrates has been investigated. Upon conventional annealing in air, the CaHfOx films remain amorphous up to an annealing temperature of 800 degreesC for annealing times of 1 h. This recrystallization temperature is significantly higher than that reported for HfO2 subjected to rapid thermal annealing. Metal-insulator-semiconductor structures with Pt gate electrodes were fabricated with various CaHfOx film thickness for capacitance-voltage and leakage current measurements. From this, the permittivity of CaHfOx was determined, along with interface layer capacitance for films on Si. The enhanced stability against polycrystalline grain growth, along with the thermodynamic stability of both CaO and HfO2 in contact with Si, suggests that CaHfOx may be an attractive gate dielectric for future generation metal-oxide-semiconductor field-effect transistor applications. (C) 2003 Elsevier Ltd. All rights reserved.