Lam Research Corporation

Tri Le

Sean S Kang

Douglas L Keil

Rao Annapragada

Bi-Ming Yen

Siyi Li

Scott Briggs

Eric D Wagganer

Jim Bowers

Sm Rega Sadjadi

The invention is a method of etching an integrated circuit (IC) structure that includes a metal hard mask layer. The etching of the metal hard mask layer is performed by first feeding a gas mixture comprising a fluorine containing gas and oxygen (O) gas to a reactor. The method then proceeds to generate a plasma that etches the metal hard mask layer. The method can be applied to either performing a via etch or a trench etch. Additionally, the invention teaches the removal of a photoresist layer without affecting the metal hard mask layer.

Etching a metal hard mask for an integrated circuit structure

A semiconductor manufacturing process wherein an organic anti-reflective coating (ARC) is plasma etched with selectivity to an underlying dielectric layer and/or overlying photoresist. The etchant gas is fluorine-free and includes a carbon-containing gas such as CO gas, a nitrogen-containing gas such as N , an optional oxygen-containing gas such as O , and an optional inert carrier gas such as Ar. The etch rate of the ARC can be at least 10 times higher than that of the underlying layer. Using a combination of CO and O with N and a carrier gas such as Ar, it is possible to obtain dielectric:ARC selectivity of at least 10. The process is useful for etching contact or via openings in damascene and self-aligned contact or trench structures.

Plasma etching of organic antireflective coating

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Milpitas, CA, United States of America

Tri Le