Structural and Electrical Properties of Crystalline CeO2 Films Formed by Metalorganic Decomposition

Crystalline CeO2 films were formed on a Si (100) substrate by metalorganic decomposition at temparatures ranging from 600°C to 800°C. As-deposited films were in the amorphous state and were completely transformed to crystalline CeO2 above 600°C. However, during crystallization in oxygen atomosphere, a reaction between CeO2 and Si occurred at the interface, which resulted in the formation of a thin interfacial SiO2 layer. Capacitance-voltage measurement on these films showed good dielectric properties with a dielectric constant of 15, which is more than three times higher than that of SiO2. The modified structure of CeO2/SiO2/Si is expected to be suitable for the dielectric layer in an integrated circuit, in place of conventional dielectric films such as those of SiO2 or Si3N4.