Two Dimensional Analytical Modeling for SOI and SON MOSFET and Their Performance Comparison

During last few decade continuous device performance improvements have been achieved through a combination of device scaling, new device structures and material property improvement to its fundamental limits. Conventional silicon (bulk CMOS) technology can’t overcome the fundamental physical limitations belong to sub-micro or nanometer region which leads to alternative device technology like Silicon-on-Insulator (SOI) technology and its recent innovative modification Silicon-On-Nothing (SON) MOSFET. Analytical simulation is very important to understand the relative performance of those devices under different structural and operational parameter variations. For present analytical simulation asymmetric structure of Silicon-On-Insulator (SOI) MOSFET and Silicon-On-Nothing (SON) MOSFET are considered. The proposed structure of SON MOSFET is similar to that of the SOI MOSFET with the only exception being the oxide layer here is substituted with air which has much lower permittivity than Silicon-dioxide. Variation of threshold voltage against effective channel lengths is compared for both the structures. From our simulation it is observed that the proposed SON model has lower drain to source current (IDS) than SOI model. In our modeling based on solution of two dimensional Poisson’s equation short channel effects such as DIBL and fringing field effects are also taken into account. SON is found to provide better suppression of SCE s than SOI. The results predicted by our analytical simulation hold good agreement with experimental results.