MOSFET Compact Modeling Issues for Low Temperature (77 K – 200 K) Operation

Advanced compact models are evaluated for simulation of mixed analog-digital circuits working at low temperature (77 to 200 K). This evaluation is performed on a dual gate oxide CMOS technology with 0.18 μm / 1.8 V and 0.35 μm / 3.3 V MOSFET transistors. A detailed temperature analysis of some physical effects is performed. Specific effects, such as anomalous narrow width effect or quantization of the inversion charge, are observed at low or intermediate temperature. Some improvements of compact models will allow a very accurate description of MOS transistors at low temperature.