An Analytical Subthreshold Swing Model for fully-depleted MOSFETs with vertical Gaussian profile fabricated on modified silicon-on-insulator wafers

The objective of this study is to present an analytical subthreshold swing model for fully-depleted metal-oxide semiconductor field-effect transistors (MOSFETs) with vertical Gaussian profile fabricated on modified Silicon-on-Insulator (SOI) wafers. Commercial SOI wafers are radiation hardened by Si+ implantation which creates interface traps at buried SiO2/Si interface. Considering that channel potential is affected by non-uniform doping profile combined with process- and radiation-induced traps, the model is derived based on effective conduction path effect. The proposed model is validated by comparing analytical results with numerical simulation data obtained by using commercially available Sentaurus technology computer-aided design. The model agrees well with experimental extractions of irradiated nMOSFETs. This model is believed to be able to provide better physical insight and understanding of total dose irradiated modified SOI MOSFET devices operating in subthreshold regime.