Parasitic Barrier in Emitter-Base Junction and Its Effects on Performance of SiGe/Si HBT at Both Room Temperature and Low Temperature
SiGe/SiHBT发射结的寄生势垒及其对器件室温和低温特性的影响

The effects of segregation and out-difusion of base B dopant on the characteris tics of SiGe/Si HBT were investigated experimentally. It was found that the B se gregation occurred during epitaxially grown SiGe base by MBE may drastically deg rade the current gain of the SiGe/Si HBT at room temperature and change its low temperature behavior. Simulation was carried out to evaluate the electron parasi tic barrier formed in EB junction and to analyze the experiment results. Based o n these, the function of SiGe spacer is discussed and its optimized thickness is obtained.