公开(公告)号：DE10005442A1

公开(公告)日：2001-08-16

申请号：DE10005442

申请日：2000-02-08

Applicant: INFINEON TECHNOLOGIES AG

Inventor： STENGL REINHART ,  MEISTER THOMAS ,  SCHAEFER HERBERT ,  FRANOSCH MARTIN

IPC: H01L21/331 ,  H01L29/732 ,  H01L29/737

Abstract: The invention relates to a bipolar transistor (20) and to a method for producing the same. The inventive bipolar transistor (20) comprises a first layer (30) disposed on a substrate (10) in which layer a collector (31) is provided, a second layer (40) disposed on the first layer (30) and provided with a base recess (41) with a base (42), and at least one further, third layer (50) disposed on the second layer (40) and provided with a feed line (51) for the base (42). Said feed line (51) is in direct contact with the base (42) in a transitional zone (52) and the third layer (50) is provided with an emitter recess (53) with an emitter. The bipolar transmitter is further provided with an undercut (43) that is disposed in the second layer (40) adjoining the base recess (41) between the first (30) and the third (50) layer, said base (42) being at least partially located also in the undercut (43). In order to obtain an as low a transition resistance as possible between the feed line (51) and the base (42), an intermediate layer (70) is provided between the first (30) and the second (40) layer, said intermediate layer (70) being selectively etchable to the second layer (40). At least in the zone of the undercut (43) between the feed line (51) and the base (42) a base connection zone (45) is provided that can be adjusted independent of other production conditions. The inventive transistor is further characterized in that the intermediate layer (70) is removed in the contact zone (46) with the base (42).