Method for forming a capacitor using a silicon oxynitride etching stop layer

摘要

A polysilicon layer is deposited on a dielectric layer. A silicon oxynitride layer is then formed on the polysilicon layer. A photoresist is imprinted with a pattern on the silicon oxynitride layer to define the storage node. An etching step is used to etch the silicon oxynitride layer and the polysilicon layer to formed the storage node. A HSG silicon is deposited on the silicon oxynitride layer and on the side walls of the storage node. An isotropically etching step is performed to remove the HSG layer on the top of the storage node. The silicon oxynitride is then removed. A dielectric layer is then formed along the surface of the storage node. A conductive layer is deposited over the dielectric layer. The conductive layer is used as the top storage node.