Microwave noise in InP and SiGe HBTs: Modeling and challenges

DC, RF and noise characteristics of advanced InP/InGaAs DHBTs and Si/SiGe HBTs were measured and modeled in a broad frequency and temperature range. A systematic model for correlated noise in bipolar transistors and its implementation in HICUM/LO v.1.31 and L2 v.2.31 is presented. The models were verified on SiGe HBTs up to 500 GHz with device simulation results from hydrodynamic and Boltzmann transport equation. HICUM with its implemented noise model also shows very good agreement with measured data in a broad frequency range. The verified model was used for noise analysis of advanced InP/InGaAs DHBTs and Si/SiGe HBTs. It was shown that shot noise correlation for high/speed InP/InGaAs DHBTs is not significant. Compared to Si/SiGe HBTs a higher noise at lower microwave frequencies was observed in InP/InGaAs DHBTs due to their high base recombination current. Nevertheless InP DHBTs show a good noise performance beyond 100 GHz and, due to better f
_T
BV
_CEO
, can compete with advanced Si/SiGe HBTs for LNA design.