DESIGN, ANALYSIS AND DEVELOPMENT OF SMALL SIGNAL MODEL FOR A PDSOI DEVICE CONSIDERING FB AND SH EFFECT

Abstract

The Floating Body (FB) effect in Partially Depleted Silicon-on-Insulator (PD SOI) devices has traditionally raised concerns due to its potential to induce performance variability. Nonetheless, this phenomenon also harbors significant opportunities for enhancing energy efficiency in semiconductor devices. Notably, the capability of the FB effect to modulate threshold voltage introduces substantial improvements in analog circuit design, providing enhanced headroom and functionality, particularly in low-voltage applications. This thesis underscores the untapped potential of this established technology and introduces a novel FB Potential model that integrates considerations for impact ionization (II) and Self-Heating (SH) effects under low terminal biases (VDS and VGS). Utilizing this model, we develop analytical expressions for small-signal parameters (transconductance, gm, and output resistance, Ro) tailored to PD SOI devices. Furthermore, this study extends into the cryogenic temperature domain, where PD SOI devices begin to exhibit characteristics akin to Fully Depleted (FD) SOI devices. This transition occurs as the floating body effect diminishes and the depletion region expands at reduced temperatures, presenting intriguing implications for device operation under extreme conditions. This exploration not only advances our understanding of PD SOI devices but also opens new avenues for their application in both conventional and specialized environments.