The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1999
Filed:
Nov. 03, 1997
Enrico M Ravanelli, Monza, IT;
SGS-Thomson Microelectronics S.r.l., Agrate Brianza, IT;
Abstract
A circuit protects against electrostatic discharge and includes a transistor connected to the circuit to be protected. A semiconductor body of a first conductivity type serves as the collector. A first doped region of a second conductivity type is contained in the semiconductor body and serves as the base. A second doped region of the first conductivity type is contained in the first doped region and serves as the emitter. The first doped region includes a generally H-shaped doped region and a generally ring-shaped doped region forming an opening in which the second doped region serving as the emitter is received. The H-shaped doped region has a deeper junction surface than the junction surface of the ring-shaped doped region, and a dopant concentration that is less than the dopant concentration of the ring-shaped doped region. The H-shaped doped region achieves a low collector-to-base breakdown voltage and the ring-shaped doped region achieves a low snap-back voltage. A method for forming the transistor is also disclosed.