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:
May. 29, 2007
Filed:
Jun. 05, 2002
Frank Richter, Dresden, DE;
Dietmar Temmler, Dresden, DE;
Andreas Wich-glasen, Langebrück, DE;
Infineon Technologies, AG, Munich, DE;
Abstract
A memory cell includes a selection transistor and a trench capacitor. The trench capacitor is filled with a conductive trench filling on which an insulating covering layer is arranged. The insulating covering layer is laterally overgrown, proceeding from the substrate with a selectively grown epitaxial layer. The selection transistor is formed in the selectively grown epitaxial layer, comprises a source region connected to the trench capacitor and a drain region connected to a bit line. The junction depth of the source region is chosen so that the source region reaches as far as the insulating covering layer. Optionally, the thickness of the epitaxial layer can be reduced to a thickness by oxidation and a subsequent etching. Afterwards, a contact trench is etched through the source region down to the conductive trench filling, which trench is filled with a conductive contact and electrically connects the conductive trench filling to the source region.