Bell Telephone Laboratories

Roy A Porter

William R Harshbarger

Hyman J Levinstein

Cyril J Mogab

Thomas N Fogarty

A dry etching process for aluminum uses a silicon tetrachloride gas ambient to which is applied radio frequency power for ionizing the gas. By appropriate control of the gas pressure and power density, anisotropic etching is achieved. This gas system also is useful for etching dual layers of aluminum and doped polycrystalline silicon.

Dry etching aluminum

High density fine-line integrated structure fabrication is expedited by use of plasma etching systems which assure straight vertical walls (absence of undercutting). Critical to the sytems is choice of appropriate plasma chemistry. Appropriate systems are characterized by inclusion of recombination centers, as well as active etchant species. Recombination centers which effectively terminate etchant species lifetime in the immediate vicinity of resist walls afford means for controlling etching anisotropy. Use is foreseen in large scale integrated circuitry (LSI) and is expected to be of particular interest for extremely fine design rules, i.e., in Very Large Scale Integrated circuitry.

Device fabrication by plasma etching

A method of forming patterned insulating layers such as silicon nitride for use in integrated circuit fabrication is disclosed. The insulating layer is formed by reactive plasma deposition while the temperature of the substrate is decreased. This diminishing temperature affects the etching characteristics of the layer such that when openings are formed by a selective plasma etching, the sidewalls will be sloped at an acute angle with the substrate even when the layer is overetched.

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Whitehall, PA, United States of America

Roy A Porter