First and Second Order Piezoresistive Characteristics of CMOS FETs: Weak through Strong Inversion

摘要

Experimental results validate a continuous model describing the stress dependencies of CMOS FETs from weak through strong inversion. The model incorporates the significant impact of threshold voltage changes (through ni²) on the stress responses in all regions of operation and describes both first- and second-order longitudinal and traverse piezoresistive coefficients for PMOS and NMOS devices. Orthogonal differential pairs of MOSFETs can be utilized to directly measure the mobility component of the overall stress response.