| 摘要 |
PURPOSE: A method for making a capacitor of a semiconductor device is provided to prevent an oxidation of a barrier metal layer by forming a polysilicon spacer on a contact hole sidewall through a recess process after depositing a polysilicon buried in the contact hole before forming a metal plug, and enhance an electric characteristic of a capacitor. CONSTITUTION: An interfacial insulating layer(2) is formed on a semiconductor substrate(1), and is etched to expose the semiconductor substrate, thereby forming a contact hole. The first polysilicon layer(3)is deposited on an upper part of the contact hole, is polished to expose the interfacial insulating layer, and thus the first polysilicon layer is buried only in the contact hole. The first polysilicon layer inside of the contact hole is partially removed by a full etching process, and the first polysilicon spacer is formed on a sidewall of the contact hole. A barrier metal layer(4) is formed on the total structure. By a polishing process, the barrier metal layer is buried on only part which is removed by a full etching process. After the first SiON layer(5), a cap oxide layer, and the second SiON layer are sequentially formed on a total surface, the second SiON layer, the cap oxide layer and the first SiON layer are sequentially removed at a lower charge storage electrode forming area, and then an etching process and a cleaning process are sequentially performed to expose the barrier metal layer. A thin metal film for the lower charge storage electrode(10) is formed on the whole surface, and a photoresist layer is deposited on the whole surface. The photoresist layer is removed by a polishing process in order to expose the second SiON layer, and then the second SiON layer is removed by a dry etching process. After a residual photoresist layer is removed, the cap oxide layer is removed by a wet etching process, thereby forming a cylinder-type lower charge storage electrode. A dielectric layer and an upper charge storage electrode are formed on the total surface.
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