Methods and apparatus for bipolar junction transistors (BJTs) are disclosed. A BJT comprises a collector made of p-type semiconductor material, a base made of n-type well on the collector; and an emitter comprising a p+ region on the base and a SiGe layer on the p+ region. The BJT can be formed by providing a semiconductor substrate comprising a collector, a base on the collector, forming a sacrificial layer on the base, patterning a first photoresist on the sacrificial layer to expose an opening surrounded by a STI within the base; implanting a p-type material through the sacrificial layer into an area of the base, forming a p+ region from the p-type implant; forming a SiGe layer on the etched p+ region to form an emitter. The process can be shared with manufacturing a polysilicon transistor up through the step of patterning a first photoresist on the sacrificial layer.