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:
Nov. 08, 1983
Filed:
Dec. 13, 1982
Wolfgang Mueller, Putzbrunn, DE;
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
The invention provides a method of manufacturing dynamic semiconductor memory cells having random access (RAM) in accordance with the double polysilicon gate technology, with which insulation of adjacent, active regions occurs by thick oxide regions, produced according to known LOCOS technology and with which, for increasing cell capacity, a boron and arsenic ion implantation is executed into the memory region with the use of a photoresist mask. In order to increase component density, the oxide thickness in the memory region/thick oxide transistor region is reduced in a multi-stage etching sequence, axially as well as laterally, so that a gain of about 25% in memory surface and a gain of more than 10 volts in blocking bias is achieved. The inventive method is particularly useful in the production of LSI Si.sup.2 gate RAM memories.