Liquid-phase-deposited barium titanate thin films on silicon

Abstract

Using a mixture of hexafluorotitanic acid, barium nitrate and boric acid, high refractive index (1.54) barium titanate films can be deposited on silicon substrates. The deposited barium titanate films have featureless surfaces. The deposition temperature is near room temperature (80°C). However, there are many fluorine and silicon incorporations in the films. The refractive index of the as-deposited film is 1.54. By current-voltage measurement, the leakage current of the as-deposited film with a thickness of 1000 Å is about 9.48×10^-7 A cm^-2 at the electrical field intensity of 0.3 MV cm^-1. By capacitance-voltage measurement, the effective oxide charge of the liquid-phase-deposited barium titanate film is 3.06×10¹¹ cm^-2 and the static dielectric constant is about 22.