| 摘要 |
The invention has disclosed a method for forming a multi-cylinder capacitor with simplified steps. First, first and second insulating layers are sequentially formed on a semiconductor substrate. Next, an alternate polysilicon layer is deposited. The alternate polysilicon layer includes a plurality of undoped polysilicon films alternating with a plurality of doped polysilicon films. Thereafter, a portion of said plurality of doped polysilicon films is selectively etched by utilizing the etching selectivity between said plurality of undoped and doped polysilicon films. Finally, the second insulating layer is removed and the undoped polysilicon films are doped to form multi-cylinder electrodes. According to the invention, the reliability of the multi-cylinder capacitor is improved and the cost of production is reduced. In addition, it is not necessary to add other steps if the number of cylindrical electrodes increases.
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