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:
Jan. 29, 2002
Filed:
Feb. 12, 1999
Toshiyuki Hirota, Tokyo, JP;
Ichiro Honma, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A hemispherical grained (HSG) lower electrode, and its manufacturing method, are disclosed in which the yield is enhanced by suppressing the depletion due to insufficient diffusion of an impurity into the hemispherical grains (abbreviated also as HSGs) to reduce the deterioration in the capacity caused by the defect on the negative (lower) electrode side, and preventing the fracture of the HSGs. In a method of forming a capacitor composed of a polysilicon lower electrode, a dielectric film, and an upper electrode, the method of this invention includes at least a step of forming HSG silicon on the lower electrode, where each of its grains has a neck with decreased diameter on the side of the contact plane with the lower electrode, a step of depositing a silicon film covering the HSGs by filling the gaps between the lower electrode in the periphery of the necks and the HSGs while maintaining the rugged shape of the formed HSGs, a step of forming a dielectric film, and a step of forming an upper electrode.