| 摘要 |
The present invention is a method of manufacturing a high density capacitors for use in semiconductor memories. High etching selectivity between BPSG (borophososilicate glass) and CVD-oxide (chemical vapor deposition oxide) is used to fabricate a multiple fin-shape capacitor with a plurality of horizontal fins and vertical pillars. First, a contact hole formed on a semiconductor substrate using an etching process. A first polysilicon layer is then deposited in the contact hole to form a plug. A composition layer consists of BPSG and silicon oxide formed on the substrate. Then a opening is formed in the composition layer to serve as a storage node. A highly selective etching is then used to etch the BPSG sublayers of the composition layer. Next, a second polysilicon layer is formed along the surface of the composition layer, the substrate and the plug. Then a SOG layer is formed along the surface of the second polysilicon layer. A CMP process is used to polish a portion of the SOG layer and a portion of the second polysilicon layer on the top of the composition layer. The SOG layer and the composition layer are subsequently removed by BOE solution. A dielectric film is then formed on the second polysilicon layer and the substrate. Finally, a third polysilicon layer is formed along the surface of the dielectric layer. Thus, a capacitor with a plurality of horizontal fins and vertical pillars is formed.
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