| 摘要 |
A combination of gases including at least a fluorocarbon gas, oxygen, and an inert sputter gas is employed to etch at least one opening into an organic photoresist. The amount of oxygen is controlled to a level that limits conversion of a metallic nitride material in an underlying hard mask layer to a metal oxide, and causes organic polymers generated from the organic photoresist to cover peripheral regions of each opening formed in the organic photoresist. The hard mask layer is etched with a taper by the oxygen-limited fluorine-based etch chemistry provided by the combination of gases. The taper angle can be controlled such that a shrink ratio of the lateral dimension by the etch can exceed 2.0. |
