Disclosed is a method of manufacturing a heterojunction bipolar transistor comprising a substrate, an upper region of said substrate comprising an active region of the bipolar transistor bordered by shallow trench insulation, said active region comprising a buried collector region extending to a depth beyond the depth of the shallow trench insulation, the method comprising forming a trench in the substrate adjacent to said active region, said trench extending through the shallow trench insulation; at least partially filling said trench with an impurity; and forming a collector sinker in the substrate by developing said impurity to extend into the substrate to a depth beyond the depth of the shallow trench insulation. An IC comprising a heterojunction bipolar transistor manufactured by this method is also disclosed.