BIPOLAR TRANSISTOR WITH A REDUCED BASE RESISTANCE, AND METHOD FOR THE PRODUCTION OF A BASE CONNECTION REGION FOR A BIPOLAR TRANSISTOR STRUCTURE

摘要

To reduce the base resistance in the bipolar transistor structure, the base connection region is designed as a multilayer structure. The multilayer structure contains a doped polysilicon layer (3), an electrically conducting diffusion barrier layer (4) which prevents an upward diffusion of the dopants from the polysilicon layer (3) and, consequently, a dopant depletion in the polysilicon layer (3), a metal silicide layer (5) and an SiO2 layer (6). The polysilicon (3), the diffusion barrier (4) and the metal silicide layers (5) have common, vertical etching profiles.