SUPPRESSION OF BORON TRANSIENT ENHANCED DIFFUSION IN SIGE HETEROJUNCTION BIPOLAR-TRANSISTORS BY CARBON INCORPORATION

In this work, we demonstrate that the incorporation of carbon in the b ase of a npn Si/SiGe/Si heterojunction bipolar transistor dramatically reduces the outdiffusion of boron from the base under postgrowth impl antation and annealing procedures. Without the addition of C, these pr ocesses would lead to transistors with vastly degraded transistor char acteristics. This reduction in B diffusion, when compared to devices w ithout C, has been observed by both secondary ion mass spectroscopy an d improved electrical characteristics. (C) 1997 American Institute of Physics.