| 摘要 |
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.
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