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:
Oct. 06, 2008
Filed:
Jan. 10, 2005
Josef Willer, Riemerling, DE;
Franz Hofmann, München, DE;
Armin Kohlhase, Neubiberg, DE;
Christoph Ludwig, Langebrück, DE;
Josef Willer, Riemerling, DE;
Franz Hofmann, München, DE;
Armin Kohlhase, Neubiberg, DE;
Christoph Ludwig, Langebrück, DE;
Qimonda Flash GmbH, Dresden, DE;
Abstract
Memory cell transistors with back-channel isolation are produced without using an SOI substrate. With the word line stack acting as a mask, the semiconductor material is etched on both sides of the world line, first anisotropically and then isotropically to widen the etch hole and form an undercut beneath the gate electrode and at a distance from the ONO storage layer forming the gate dielectric. The undercut is filled, whereby a buried oxide layer of at least 20 nm maximum thickness is formed underneath the channel region. The latter is p-doped at a density of at least 10cm.