An Analysis of SiGe/Si HBT's DC Characteristics

The SiGe/Si HBT's layer structure with a novel high speed base transportation was designed upon considering both doping engineering and band engineering, On this structure, the SiGe/Si HBT with advanced performance was fabricated in 3μm processing line. Its main DC characteristics are shown as follows:The maximum current gain β_max (at room temperature) is up to 300; the maximum current gain β_max (at 77K)is 8000; the early voltage is 300V and the leakage current is at nA level. Furthermore,the output characteristics at room temperature (small injection and large injection) and at 77K (small injection and large injection)are shown, and the main factors which influence the current gain are discussed.