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:
Sep. 09, 1997
Filed:
Mar. 15, 1995
Karl Paul Muller, Wappingers Falls, NY (US);
Wesley C Natzle, New Paltz, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Isotropic deposition of a selectively etchable material in an opening in a body of material followed by isotropic deposition of an etch resistant material forms a mask for anisotropic etching of the selectively etchable material at potentially sub-lithographic dimensions to form potentially sub-lithographic features within a trench. This process can be exploited to form a folded trench capacitor in which a trench is formed with one or more upstanding and possibly hollow features therein; effectively multiplying the surface area and or allowing reduced trench depth for a given charge storage capacity or a combination thereof. Further surface treatments such as deposition of hemispherical grain silicon can be used to further enhance the effective area of the trench. Isolation structures of sub-lithographic dimensions can also be formed by depositing appropriate materials within the trenches formed in accordance with the mask.