Extension of standard SPICE SiGe HBT models in the cryogenic temperature range

Although it has been demonstrated that the SiGe HBTs can achieve faster unloaded circuit speed at cryogenic temperature than at room temperature, modelling of the SiGe HBTs at low temperature has been limited. It is known that the standard SPICE models of bipolar transistor are effective and guarantee the valid results only up to a temperature of minus 100°C. Therefore, in this paper an accurate and robust compact SPICE SiGe HBT model for extended low temperature range up to minus 195°C is presented. Comparison of measurements and simulation results shows an error not more than 10-15%.