Bipolar semiconductor component manufacturing

摘要

The method involves forming an oxide layer (32) and a polysilicon layer (34) on a substrate (30), a further oxide layer with a predetermined pattern being then formed on the polysilicon layer. A further intermediate layer is formed on the polysilicon layer side walls, and an oxide layer on the polysilicon layer by which the polysilicon layer is selectively doped. After removal of the intermediate layer, the polysilicon is then selectively etched, e.g. using CVD, down to the initial oxide layer using the latter oxide layer as a mask to form two trenches. The undoped region between the two trenches is then removed using an alkali solution and a further intermediate layer is provided on the sidewalls of the doped polysilicon layers. A further oxide layer (46) is formed, using thermal oxidation, on the exposed part of the initial oxide layer, dopants being simultaneously diffused from the latter intermediate layer to form a base-contact region (48). A third intermediate layer (52) is provided on the latter oxide layer and an intrinsic base region (50) is produced via injection from the initial oxide layer exposed ends. These exposed ends are then removed and an emitter contact hole is produced which is subsequently filled with a polysilicon material to form an emitter electrode (56). An emitter contact region is formed diffusion of dopants from the intrinsic base region by thermal handling.