Munehiro Shibuya

Structure and Properties of Silicon Titanium Oxide Films Prepared by Plasma-Enhanced Chemical Vapor Deposition Method

We have developed a novel material of silicon titanium oxide with high dielectric constant and low leakage current. The silicon titanium oxide films were prepared by plasma-enhanced chemical vapor deposition (plasma CVD) with the gas mixture of TiCl4-SiH4-N2O. It was found that these films have intermediate properties of silicon dioxide and titanium dioxide by varying the ratio of SiH4/(SiH4+TiCl4). The properties of silicon titanium oxide nearly corresponded to those of Ta2O5 when the gas mixture ratio was 0.075, with a dielectric constant of 18 and a leakage current density of 2.5×10-8 A/cm2 at 1 MV/cm.

Substrate Potential Effects on Low-Temperature Preparation of SrTiO3 Thin Films by RF Magnetron Sputtering

SrTiO3 films have been prepared by RF magnetron sputtering at a low substrate temperature of 200?C. The dielectric properties of the films deposited wherein substrate potentials were floated were fairly dependent on the film thickness, which was related to a change of the substrate potential at the initial stage of deposition. In order to control the substrate potential, positive DC bias voltages were applied on substrates, so that leakage current densities of the films were markedly reduced while their dielectric constants and structural properties remained almost the same. A 300-nm-thick film deposited with DC bias voltages >+5 V exhibited. good dielectric properties with a leakage current density of 1?10-7 A/cm2 and a dielectric constant of 90.