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. 08, 1989
Filed:
Jul. 16, 1987
Karl-Heinz Kuesters, Munich, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A transistor varactor for dynamic semiconductor storage means which are formed on a doped silicon substrate having a high integration density and which includes one field effect transistor which has source and drain and a gate and a varactor overlaps the gate electrode and is formed as a stacked capacitor. The gate electrode and the varactor are electrically isolated from each other by insulating layers and the contact of the source zone is electrically isolated from the gate electrode by the insulating layers and the upper polysilicon layer of the varactor formed by oxidation of the side portions of the polysilicon layer. The contact of the source zone adjusts to the gate electrode and to the polysilicon layer in that the distance of the contact of the source zone relative to the gate electrode and the polysilicon layer is independent of the photographic accuracy. A buried contact between the polysilicon layer and the drain zone is self-adjusted relative to the gate electrode.