Process to pattern thick TiW metal layers using uniform and selective etching

Abstract

A method processes a thick TiW metal layer (12) on a dielectric layer (15), where the dielectric layer (15) has been deposited on a substrate (14), such as a silicon substrate. The method deposits the TiW metal layer (12) onto the dielectric layer (15), such as silicon dioxide or silicon nitride, and then deposits a photoresist (10) over the TiW metal layer (12). The method removes substantially all of the TiW metal layer (12) not in contact with the photoresist (10) with a uniform etch, such as not more than 80% to 90% of the deposited TiW metal layer. Then, the TiW metal layer (12) is selectively etched to the dielectric layer (15), to remove the TiW metal layer (12) faster than the dielectric layer (15), such as 2.7 times faster.

Dependencies are inferred from the claim text.