Planar semiconductor structure breakdown voltage protection using voltage divider

US4599638A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventor

• Peter Flohrs · Reutlingen, DE

Key dates

• Filing date: Sep 15, 1983
• Grant date: Jul 8, 1986
• Expiry date: Sep 15, 2003

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/642

Abstract

A planar semiconductor structure is proposed which has a monocrystalline semiconductor chip (10) of a specific conductivity type, a first zone (11) of the opposite conductivity type introduced into the semiconductor chip (10) by diffusion from a main surface and together with the material making up the semiconductor chip (10) forming a p-n junction (12), and a passivation layer (13) covering this same main surface of the semiconductor chip (10) with the exception of contact windows. A second, annular zone (14) acting as a stop ring and having the same conductivity type as the basic material making up the semiconductor chip (10) but a higher concentration of impurities is introduced into the semiconductor chip (10) from the same main surface such that it surrounds the first zone (11). A metallizing coating acting as a cover electrode (15) is applied to the passivation layer (13), surrounding the p-n junction (12) annularly and overlapping the line of intersection of this junction with the main surface of the semiconductor chip (10). This metallizing coating extends into the region above the annular zone (14). The potential of the cover electrode (15) is adjustable such that it is be…