International Business Machines Corporation

Karey L Holland

William J Cote

Terrance M Wright

Robert C Bausmith

John Edward Cronin

Carter W Kaanta

Pei-ing P Lee

Allan D Abrams

Steven P Holland

A method for dry etching metals that form low volatility chlordes, in which Z-Cl reaction products are controllably introduced into a conventional Cl-based plasma independent of the workpiece. The Z-Cl products (e.g., AlCl.sub.3, GaCl.sub.3, etc.) are metal chlorides that have both electron acceptor and chloride donor properties. Thus, metals M (e.g., cobalt, copper and nickel) that usually produce low volatility chlorides can be controllably complexed to form high volatility Z.sub.x Cl.sub.y M.sub.z reaction products.

Etching metal films with complexing chloride plasma

A method for anisotropically etching a thick tungsten layer atop a thin underlayer comprised of titanium nitride, by exposure to a gaseous plasma comprised of a binary mixture of chlorine gas and oxygen, wherein oxygen comprises approximately 25%-45% of the mixture by volume. This plasma provides a combination of high tungsten etch rate, highly uniform etching, anisotropic profiles, and high etch rate ratio to underlaying glass passivation layers.

Anisotropic etch process for tungsten metallurgy

A method of selectively tailoring the slope of via hole sidewalls. A first polyimide layer (in which the vias are to be formed) is covered by a strippable layer, and the two layers are isotropically etched. By varying the thickness of the strippable layer with respect to that of the polyimide layer, the slope of the via hole sidewalls can be controlled.

Tailoring of via-hole sidewall slope

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Essex Junction, VT, United States of America

Karey L Holland