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:
Nov. 14, 2000
Filed:
Sep. 23, 1998
Enrico M Ravanelli, Monza, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
An electrostatic discharge protection circuit for integration into an integrated circuit device. The protection circuit includes at least one transistor having a first terminal connected to an input or output terminal of the integrated circuit device, a second terminal connected to a supply line for the integrated circuit device, and a control terminal connected to ground. In a preferred embodiment, the transistor is formed by a structure that includes a substrate of a first conductivity type, a first region of a second conductivity type, a second region of the first conductivity type, a third region of the first conductivity type, and a fourth region of the second conductivity type. The third region has greater conductivity than the substrate and the fourth region has greater conductivity than the first region. These regions are formed such that the first region extends from a surface of the substrate, the second region extends from the surface into a portion of the first region, and the third region has one portion buried beneath the first region and another portion extending to the surface. Additionally, the fourth region extends from the second region with a ring shape so as to form a bipolar junction with the second region in an area beneath a non-peripheral portion of the second region.