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:
Feb. 20, 2001
Filed:
May. 28, 1998
Toshiharu Furukawa, Essex Junction, VT (US);
Mark C. Hakey, Milton, VT (US);
Steven J. Holmes, Milton, VT (US);
David Horak, Essex Junction, VT (US);
William H. Ma, Fishkill, NY (US);
James M. Never, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A bottle-shaped trench capacitor with a buried plate is formed in a controlled etch process. The bottle-shape is fabricated by etching deep trenches from a layered substrate, using the layers as a mask, and covering the side walls of the substrate with protective oxide and nitride layers. With the side walls covered, deep trench etching is then resumed, and a lower trench portion, below the protective layers of the side wall are formed. By diffusing a first dopant in the lower portion of the deep trench region, using the side wall protective layers as a mask, an etch stop is established for a wet etch process at the p/n junction established by the first dopant. The width of the lower trench portion is regulated by the time and temperature of the diffusion. Removing the doped material and applying a second dopant to the lower trench portion establishes a continuous buried plate region between trenches. A capacitor is formed by applying an insulating layer to the trench and filling with a conductor.