Characterization of polysilicon bipolar transistors by low-frequency noiseand correlation noise measurements

Low-frequency noise measurements are performed in order to characterize qua si-self-aligned polysilicon bipolar transistors. After a theoretical analys is we present a study of the influence of the base source resistance on the correlation between the input and the output noise sources of the transist ors. We observe that a partial correlation between the input and the output voltage noise sources appears and varies with the source resistance, the b ias and the emitter size of the transistors. As a consequence we demonstrat e the influence of the fluctuations of the collector current. Taking into a ccount these results, we propose different extraction methods for the emitt er and base series resistances. To confirm and extend these measurements, h igh-frequency results are also presented.