Metal-Oxide-Semiconductor (MOS) Devices Composed of Biomimetically Synthesized TiO_2 Dielectric Thin Films

摘要

We propose a novel biomimetic method to prepare amorphous TiO_2 thin films on a silicon substrate for metal-oxide-semiconductor field-effect-transistors (MOSFET). The film was formed on a self-assembled monolayer of siloxane. The dielectric permittivity of TiO_2 thin film, the dielectric properties of TiO_2/Si interface and the leakage current density were evaluated by measuring the current-voltage characteristics and high-frequency capacitance-voltage characteristics of the MOS device. Very low leakage current was observed under high electric fields and the TiO_2 thin film showed dielectric permittivity larger than 20, which is about 5-6 times as large as that of usual SiO_2. This result indicates that TiO_2 thin film synthesized biomimetically at room temperature can be a candidate material to replace with SiO_2 layers currently employed for gate dielectrics in MOSFET's.