Process for the manufacture of a side-limited monocrystalline region in a bipolar transistor

摘要

On a substrate (11) made of monocrystalline semiconductor material, a first layer (12) and a second layer (13) are generated, the first layer (12) being selectively etchable both with respect to the substrate (11) and to the second layer (13). The first layer (12) and the second layer (13) are structured in such a way, that undercutting (121) of the first layer (12) under the second layer (13) is produced, in which the surface of the substrate (11) is exposed. By means of selective epitaxy, a monocrystalline region (16) is generated on the exposed surface of the substrate (11). The process can be used for generating a channel region for a MOS transistor or a base for a bipolar transistor.