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:
Dec. 17, 1991
Filed:
Aug. 27, 1990
Siegfried Roehl, Sauerlach, DE;
Josef Mathuni, Munich, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
Method for manufacturing a trench capacitor of a one-transistor memory cell in a semiconductor substrate with a self-aligned cooperating capacitor electrode. In a one-transistor memory cell having a trench capacitor in a semiconductor substrate (1), a field oxide (3) that isolates different cells is exploited for a self-aligning process. After the formation of a first electrode and of a dielectrode (5) of the capacitor, a conductive layer (6) is applied surface-wide, the upper edge thereof being higher over the field oxide (3) than over the field-oxide-free locations of the substrate (1). The raised location is exposed in a re-etching process upon employment of a planarizing auxiliary layer (9), and a sub-layer (10, 10') is selectively applied thereon, either by local oxidation, selective or non-selective deposition. This sub-layer (10, 10') serves as a self-aligned mask for the structuring of the conductive layer (6) as a cooperating electrode of the trench capacitor.