Integrated semiconductor circuit with protective structure for protection against electrostatic discharge

An integrated semiconductor device, comprising:

• a semiconductor body and an integrated semiconductor circuit disposed in said semiconductor body;
• a terminal pad and a connecting line electrically connecting said terminal pad to said integrated semiconductor circuit;
• a first busbar carrying a first supply potential during an operation of said integrated semiconductor circuit;
• a second busbar carrying a second supply potential during an operation of said integrated semiconductor circuit;
• and
• a protective element for protecting said integrated semiconductor circuit against electrostatic discharge connected between said terminal pad and said integrated semiconductor circuit and to at least one of said first and second busbars;
• and
• at least one base zone of a second conductivity type introduced into a partial region of an epitaxial layer of the first conductivity type, said at least one base zone having an outer edge;
• said protective element including at least one integrated vertical protective transistor having a load path connected between said connecting line and one of said first and second busbars and having a base and a collector;
• said collector of said protective transistor formed in said semiconductor body as at least one buried layer of a first conductivity type, said at least one buried layer having a ring-shaped structure with an inner edge;
• said outer edge of said at least one base zone being laterally offset with respect to said inner edge of said ring-shaped structure of said at least one buried layer of said collector.