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:
Jun. 02, 1987
Filed:
Aug. 13, 1984
Peter E Cottrell, Essex Junction, VT (US);
William J Craig, South Burlington, VT (US);
Ronald R Troutman, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A charge pumping structure is disclosed for use in a substrate bias voltage generator. It includes a capacitor on a substrate region for coupling to a first node periodic voltage signals received at a second node. A first diode structure provides a current path from the first node to the substrate and a second diode structure provides a current path between the first node and a reference potential, which is typically the ground. The first diode structure includes a PN junction diode, an isolation ring for collecting minority charge carriers injected into the substrate and is constructed on a portion of the substrate that has a lower doping concentration than the underlying substrate portion establishing a built-in electric field which inhibits the flow of minority carriers from the first diode to the underlying substrate. The second diode structure may include a pocket type PN junction diode constructed so that majority carriers are prevented from moving back into the substrate from which the substrate bias voltage generator will have to remove them.