Finite element analysis of SiGe heterojunction devices
Two SiGe devices, a n/sup +/-n-p heterojunction diode and an n-p-n HBT have been analyzed using a two-dimensional bipolar device simulator which is based on the finite element method. The various shape functions used in the finite element formulations have been detailed. The dependence of the device characteristics on the various Ge mole-fraction material parameters has been studied. The variation of current gain of SiGe HBT with temperature is discussed. >