Junction capacitance models of SiGe HBT
SiGe HBT势垒电容模型

When SiGe HBT is in the case of normal operation, depleted approximation is not suited, and the influence of movable charge should be taken into account when considering of their junction capacitance. Based on the analysis and study of the carrier transport of SiGe HBT, emitter junction capacitance model is developed by considering the carrier distribution, and the collector junction capacitance model is also established for different current densities including base extending effect. The junction capacitance models are used to simulate frequency characteristics. The results of simulation show good agreements with the experimental data.