Limits and improvements of TCAD piezoresistive models in FDSOI transistors

The usefulness for technology computer-aided design (TCAD) tools of the bulk linear piezoresistive theory is limited for two reasons. The first is that the normal effective field breaks piezoresistive tensor symmetries increasing the number of independent coefficients from three to six. The second reason is due to the non-linear behavior of the mobility change at high stress values. In this paper, we investigated the six-order polynomial piezoresistive model recently published by Synopsys (MCmob) [16,17]. We demonstrated that a 3D k-space Monte-Carlo solver cannot be used for MCmob parameters calibration (as initially proposed in [16]) as it does not account for quantum confinement. Instead, using self-consistent k.p Poisson-Schrodinger solvers (Kubo-2Dk Greenwood formalism [14, 15] for mobility), we determined a set of parameters for MCmob in the case of p-type FDSOI MOSFETs with <;100> and <;110>-oriented silicon channels on (100)-oriented wafers.