| 摘要 |
An apparatus and method for in-situ etching of a substrate comprising both a polysilicon layer and an overlying dielectric layer. An embodiment of the method comprises an anisotropic etch of the dielectric layer in a chamber using a first fluorinated gas (such as CF4, NF3, SF6, and the like) as an etch gas to expose at least a portion of underlying polysilicon layer. Following the anisotropic etch and without removing the substrate from the chamber, i.e., in situ, an isotropic etch is preformed on the underlying polysilicon layer using a second fluorinated gas (such as CF4, NF3, SF6, and the like) as an etch gas.
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