Novel Methodology for MOSFET Parameter Extraction From Weak to Strong Inversion Range in Ohmic Operation at Very Cryogenic Temperatures

Abstract

In this article, a new methodology is proposed for MOSFET parameter extraction and modeling of transfer behavior from weak to strong inversion range in ohmic operation at cryogenic temperatures. The propounded methodology is based on an empirical mobility law which considers that the Coulomb scattering mechanism prevails in weak inversion, while it is the surface roughness mechanism in strong inversion at temperatures lower than 30 K. It permits to extraction of the inversion charge from weak to strong inversion range through I – V measurements. It appears that the estimated inversion charge behavior may concur with the one analytically constructed using the Lambert-W function approach. The new methodology can be employed when the conventional mobility law, through a negative first-order intrinsic mobility attenuation factor, fails to model the Coulomb scattering mechanism in weak inversion at very cryogenic temperatures.