A method for improving the SiGe bipolar yield as well as fabricating a SiGe heterojunction
bipolar transistor is provided. The inventive method includes ion-implanting carbon,
C, into at one of the following regions of the device: the collector region, the
sub-collector region, the extrinsic base regions, and the collector-base junction
region. In a preferred embodiment each of the aforesaid regions include C implants.