Charge transient behaviour and spectroscopic ellipsometry characteristics of TiN/HfSiO MOS capacitors

Abstract

A combination of two powerful techniques, namely, charge deep level transient spectroscopy and spectroscopic ellipsometry is employed on atomic layer deposited Si-metal oxide semiconductor capacitors (MOSCAPs) to investigate the energy efficiency of the physical process. Ultra-thin TiN/HfSiO acted as gate-dielectric stack on Si substrate was carefully subjected to rapid thermal processing and subsequent spectroscopic measurements to determine the transient behaviour of charges and electro-optical characteristics. Some key parameters such as trap concentration, activation energy required to surmount the traps, capture cross section, refractive index and extinction coefficient are found to play an important role in order to assess the energy efficiency of the devices both in terms of post-process quality of the retained surface and residual efficiency of the process by virtue of dynamics at atomistic scales. The results may provide a useful insight to the Si manufacturing protocols at ever decreasing nodes with desirable energy efficiency.