Microscopic modeling of high frequency noise in SiGe HBTs

The SIMS doping profile of SiGe heterojunction bipolar transistor is calibrated for best agreement of the hydrodynamic model results with the experiment. DC and small-signal data is used for the calibration. The terminal current noise calculations are performed using both hydrodynamic and drift-diffusion models with the calibrated doping profile. The calculation results are compared with the experimental values. Overall good agreement for the minimum noise figure, the noise resistance, and the optimum reflection coefficient is obtained. The difference between the hydrodynamic and drift-diffusion model results is analyzed using spectral intensities of the base and collector current fluctuations.