Analytical models of subthreshold current and swing of short-channel strained-Si (s-Si) on Silicon–Germanium-on-Insulator (SGOI) MOSFETs

• Analytical model of subthreshold current is derived for strained-Si on SGOI MOSFET.
• Analytical subthreshold swing model is developed for strained-Si on SGOI MOSFET.
• Parabolic approximation is used for determination of the 2D channel potential.
• ATLAS simulation data are used for the verification of theoretical results.
• Theoretical results are in good agreement with simulation results.

In this paper, surface potential based analytical models of subthreshold current and subthreshold swing of the strained-Si (s-Si) on Silicon–Germanium-on-Insulator (SGOI) MOSFETs have been presented. The models are based on the solution of the 2D Poisson’s equation in the fully depleted channel region by approximating the potential in vertical direction of the channel. The thus obtained potential distribution function has been employed in deriving the closed form expressions of subthreshold current and subthreshold swing. The subthreshold characteristics have been studied as a function of various device parameters such as Ge mole fraction (x), gate length (Lg), gate oxide thickness (tf) and channel thickness (ts-Si). The proposed analytical model results have been validated by comparing with the simulation data obtained by the 2D device simulator ATLAS™ from Silvaco.