Structural and Electrical Properties of Crystalline TiO2 Thin Films Formed by Metalorganic Decomposition

Abstract

Titanium oxide (TiO2) thin films were formed on a Si substrate by metalorganic decomposition at temperatures ranging from 600°C to 1000°C. As-deposited films were in the amorphous state and were completely transformed after annealing at 600°C to a crystalline structure with anatase as its main component. During crystallization in oxygen atomosphere, a reaction between TiO2 and Si occurred at the interface, which resulted in the formation of a thin interfacial SiO2 layer. Capacitance-voltage measurement showed good dielectric properties with a maximum dielectric constant of 76 for films annealed at 700°C. For the crystallized TiO2 films, the interface trap density was 1×1011 cm-2eV-1, and the leakage current was 1×10-8 A/cm2 at 0.2 MV/cm. The modified structure of TiO2/SiO2/Si is expected to be suitable for the dielectric layer in an integrated circuit in place of SiO2 or Si3N4 films.