ALD-TiO2 Preparation and Characterization for Metal-Insulator-Silicon Photoelectrochemical Applications

Abstract

Atomic layer deposition of ultrathin TiO2 films for metal-insulator-silicon photoelectrochemical applications is accomplished in a custom built ALD chamber using the precursor tetrakis(dimethylamido)titanium (TDMAT) and water vapor co-reactant. This paper discusses the procedures used to achieve high quality, repeatable depositions for this particular application. Characterization of the ALD-TiO2 films can be performed by metal-insulator-semiconductor (MIS) structure capacitance-voltage methods. Electrochemical characterization methods are also used to determine the approximate film resistivity, photovoltage, differential resistances, and stability of an MIS device performing water splitting. This set of electrochemical measurements allows for the rapid characterization of ultrathin ALD films for MIS photoelectrochemical applications.