Room temperature plasma oxidation mechanism to obtain ultrathin silicon oxide and titanium oxide layers

摘要

Scaling rules for sub-micrometric MOS devices have led to the necessity of ultrathin dielectric films and high-k dielectric layers. In this paper we present first results of room temperature plasma oxidation to obtain ultrathin layers of SiO_2 and TiO_2. The oxidation process in O_2 and N_2O shows a power law dependence with time and inverse proportionality with pressure. The oxidation rate is inversely proportional to pressure for both high and medium resistivities substrates. An oxidation model is proposed to explain this behavior. Ellipsometric and C―V characterization show complete oxidation of titanium verifying that a dielectric layer is formed.