Modelling of GE concentration effects on carrier mobility in SI1−xGEx HBTs

Despite its wide usage, Si based semiconductor devices have limitations in terms of gain, and electron/hole mobility. This eventually limits other performance parameters like amplification, transit time or maximum operating frequency. In an attempt to maximize the efficiency by improving the properties, SiGe alloys with varying Germanium concentration are fabricated. It is necessary to consider the parameters of Heterojunction Bipolar Transistors (HBT) and demonstrate their improvements due to Ge addition. This paper discusses the important parameters associated with SiGe HBT. It endeavors to empirically correct the existing expressions that relate to these properties and helps by providing a better gauge to the device´s properties.