US 2003/0143805 A1Published application

Semiconductor device having a capacitor and method of manufacturing the same

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorTomonori Okudaira

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Abstract

Sputter etching of silicon oxide films (24 and 22) is performed with an etching gas such as C4F8. Since a silicon nitride film (21) is little etched at this time, when the etching is performed under a condition of sufficient overetching for the silicon oxide films (24 and 22), the silicon nitride film (21) serves as an etching stopper, and the silicon oxide film (24) on a platinum film (23) and the silicon oxide film (22) other than a portion below the platinum film (23) are completely removed and the silicon oxide film (22) remains only below the platinum film (23), to form a protrusion of a layer consisting of the silicon oxide film (22) and the platinum film (23) from a surface of the silicon nitride film (21). Thus, in patterning a capacitor lower electrode by chemical etching, a nonuniform etching caused by temperature distribution on a substrate or among a plurality of substrates can be solved.

Claims11

Dependent claims

A method of manufacturing a semiconductor device which comprises a capacitor having a lower electrode selectively formed on an underlying layer, a dielectric film covering said lower electrode and an upper electrode opposed to said lower electrode with said dielectric film interposed therebetween, comprising the steps of:

(a) forming first and second etching stopper films whose materials are different from each other in this order as said underlying layer on an interlayer insulating film;
(b) forming a conductive film which is to become said lower electrode on said second etching stopper film;
(c) forming a hardmask having a pattern corresponding to a plane pattern of said lower electrode on said conductive film;
(d) patterning at least said conductive film with said hardmask used as an etching mask and said second etching stopper film as an etching stopper to form said lower electrode;
(e) completely removing at least said second etching stopper film other than a portion below said lower electrode with said first etching stopper film used as an etching stopper;
and
(f) so forming said dielectric film and said upper electrode as to cover said lower electrode and said second etching stopper film remaining below said lower electrode.

4 more elements

Dependencies are inferred from the claim text.