Plasma Etching of Polycrystalline Silicon using Thinning Technology for Application in CMOS and MEMS Technologies

Abstract

This work presents results of the study of profile evolution for Si-poly structures during plasma etching using the thinning technology in SF6/CF4/CHF3 gas mixtures. Structures with an aspect ratio (height/width) up to 5, widths end in the range of 0.3 – 0.1 μm and 0.3μm thick, were produced. Sipoly structures with high anisotropy (anisotropy factor up to 0.92-0.98) after etching were demostrated. The method can be used for fabrication of sub-micron Si-poly gates in CMOS and in fabrication of MEMS devices.