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. 21, 1982
Filed:
Aug. 25, 1980
Motoo Nakano, Yokohama, JP;
Tsutomu Ogawa, Tokyo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The invention is concerned with an improved method of producing a one-transistor cell for a dynamic RAM having a capacitor plate, a transfer gate and a shallow n.sup.+ -type region and a deeper p.sup.+ -type region for a junction capacitance. After formation of a thin oxide layer of a dielectric for an MOS capacitance, a patterned photo resist layer is formed. Using the photo resist layer as a mask, n-type impurities are doped into a semiconductor substrate. The capacitor plate and a masking layer are deposited on the photo resist layer and the thin oxide layer. P-type impurities are doped into the capacitor plate. Then, portions of the capacitor plate and masking layer on the photo resist layer are removed by removing the photo resist layer. An end portion of the capacitor plate is removed from under an edge of the remaining masking layer by etching. The p-type impurities are diffused into the silicon substrate by heating to form the deeper p.sup.+ -type region which does not extend beyond the n.sup.+ -type region.