Preparation of titanium-dioxide films by heating titanium/silicon-dioxide structures on silicon in oxygen

Abstract

When titanium/silicon-dioxide (Ti/SiO2) structures prepared by depositing titanium (Ti) on thermally oxidized silicon in vacuum were heated to temperatures of 800–1000°C in flowing oxygen gas, silicon surfaces were covered with a mixture films containing preferentially (110)-oriented Ti02 instead of the SiO2 films. The thickness of the mixture films could be determined by that of the deposited Ti films. Titanium silicide grew only in the region near between the grown mixture film and the silicon substrate. The dielectric constants of the grown mixture films increased exponentially with increasing oxidation temperature and increased slowly with increasing the Ti film thickness, while the breakdown field strength increased slowly with increasing oxidation temperature and increased exponentially with increasing the Ti film thickness. The oxide films prepared at 1000°C had dielectric constants of (15–25)εo resistivities of 1010-1011 Ω cm, and breakdown field strengths of about 106 V/cm.