Plasma-assisted Etching Research Articles

Simulation of plasma-assisted etching processes by ion-beam techniques

Fundamental aspects of plasma-assisted etching processes can be investigated in a well-defined and controllable manner by ion-beam techniques. We review here our experiments aimed at simulating a plasma environment using beams to investigate the effects of a number of fundamental parameters of plasma processes, such as the chemical identity of bombarding ions, flux of ions and neutrals to a surface, and ejection of products from a surface. Enhanced ion etching due to reactions of neutral gases with surfaces is demonstrated, and product ejection mechanisms are shown to be possible rate limiting factors in reactive etching processes. A simple chemically enhanced sputtering model suffices to account for the main features of ion-induced etching. Applications of this model to bulk plasma processes, dependence of etch yield on ion angle of incidence, and surface composition modification are suggested.

Dry etching for pattern transfer

Dry etching or plasma-assisted etching (ion beam milling, plasma etching and reactive sputter etching) has become an indispensable preparation technique for high resolution pattern transfer in IC manufacturing and other areas of microfabrication. Etching can either be due to the purely physical process of momentum transfer from ions to the solid surface (e.g. inert ion etching) or due to chemical reactions of reactive species, produced in the plasma, with the solid surface resulting in a volatile reaction product (e.g. plasma etching in a barrel reactor). However, in most dry etching methods both effects play a major role and it is possible to optimize etch selectivity and the shape of the etched profile by a proper choice of parameters.

Abstract: Plasma-assisted etching for pattern transfer

First Page