Non-uniform matching performances in mesa-isolated SOI MOSFETs

• The effect of MESA isolation on the electrical characteristics of a FDSOI MOSFET is presented, with the presence of a parasitic edge transistor. • A methodology to extract threshold voltage matching of main and parasitic transistors is presented. • Said methodology is applied to assess matching performances of our devices for different channel doping and back bias values. • The device matching is dramatically degraded for a back bias of 5 V. This degradation is attributed to the floating body being charged. This work studies the threshold voltage mismatch of mesa-isolated SOI pMOSFETs through a breakdown between edge and center contributions. Pelgrom’s law is followed if a proper care is taken in the Vt extraction method. Applied to pMOS devices we observed that despite its parasitic nature, the edge transistor mismatch is as good as that of the center, regardless of channel doping and back-gate bias. Mismatch degradation in reverse back-bias mode is observed and attributed to the presence of floating body effects.