Method for monitoring etching of resists by monitoring the flouresence of the unetched material

Abstract

A method for lithographically fabricating devices is disclosed. In accordance with the method, a sacrificial coating material (SCM), e.g., a resist, mixed with a fluorescent material is deposited onto a substrate and then etched. SCM etching is monitored by subjecting the fluorescent material within the SCM to fluorescence-inducing energy, and detecting the resulting fluorescence. Because the fluorescent material is etched away as the SCM is etched, fluorescence intensity decreases as SCM thickness is reduced. Thus, SCM etch end point is accurately determined because etch end point corresponds to the point in time when the detected fluorescence ceases.

Dependencies are inferred from the claim text.