PROCESS FOR THE FORMATION OF THE EMITTER ZONE OF A TRANSISTOR

摘要

1. Method for forming the emitter region of a transistor comprising a subcollector region (13') in a semiconductor substrate, an epitaxially grown layer (15') thereon, and a base region (27') within the latter layer, having a conductivity type opposite to the one of the subcollector region, wherein one layer (43) of non-monocrystalline silicon is deposited on said epitaxially grown layer (15') and implanted with ions of the conductivity type of the subcollector region, characterized in that at least part of the non-monocrystalline silicon forms a spatial region for the emitter region which is adjacent to and at least partially vertically displaced from said base region, that the spatial region of the emitter region is bombarded with ions of such dose and high energy that at least a part of the Gaussion distribution of the penetration depths of those ions is diven across the boundary between said non-monocrystalline layer (43) and said epitaxial layer (15'), and the transistor is annealed in order to driven the ions into the base region and to convert the non-monocrystalline silicon of the spatial region of the emitter region to an emitter region consisting of monocrystalline silicon.