ETCH ANISOTROPY OF UNDOPED POLYSILICON FILMS.

The basic etching mechanism of undoped polysilicon during reactive ion etching involves both the 'directional' ion-enhanced etching and the 'isotropic' chemical etching. Competition between these two etching mechanisms would determine the anisotropy of an etch profile, when other inhibiting effect such as a polymer coating at the sidewall does not play a role during a reactive plasma etching process. The authors will report our experimental result on poly-Si etch profiles produced by the CF//4/O//2 plasma.