New floating-body effect in partially depleted SOI pMOSFET due to direct-tunneling current in the partial n+ poly gate

A detailed analysis of the body potential impact on the performance enhancement of Body Contacted (BC) pMOSFET when the body is not grounded, is reported in this paper. Investigations on BC pMOSFET with a floating-body configuration reveal that this new floating-body effect leads to pMOSFET drive capability increase with higher transconductance, lower subthreshold slope, no off-state leakage current degradation and no kink effect. The body potential is mainly controlled by the electron tunneling from the conduction band (ECB) between the partial n+ poly-gate and the n type silicon substrate through the 1.6 nm thin gate oxide. Static characterizations of various layouts and geometries demonstrate that narrow pMOSFET and H-gate design provides the highest Ion gain due to higher body potential. Furthermore, it has been found that the largest n+ poly-gate area results in the fastest switch-on drain current transients.