Method for the manufacture of bipolar transistor structures with self-adjusting emitter and base regions for extreme high frequency circuits

US4581319A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Armin Wieder · Gauting, DE
• Hans-Christian Schaber · Gräfelfing, DE
• Siegfried Schwarzl · Neubiberg, DE

Key dates

• Filing date: Jun 1, 1984
• Grant date: Apr 8, 1986
• Expiry date: Jun 1, 2004

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/0337
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for the manufacture of bipolar transistor structures with self-adjusted emitter and base regions wherein the emitter and base regions are generated by an out-diffusion from doped polysilicon layers. Dry etching processes which produce vertical etching profiles are employed for structuring the SiO.sub.2 and polysilicon layers. The employment of additional oxidation processes for broadening the lateral edge insulation (see arrow 9) during the manufacture of the bipolar transistor structures enables self-adjusted emitter-base structures with high reproducibility in addition to advantages with respect to the electrical parameters. The method is employed for the manufacture of VLSI circuits in bipolar technology.