System and method for providing a dry-wet-dry etch procedure to create a sidewall profile of a via

摘要

A system and method is disclosed for providing a dry-wet-dry etch procedure to create a sidewall profile of a via in a semiconductor device. A first vertical anisotropic dry etch process is applied to etch through a first portion of a dielectric layer. An isotropic wet etch process is then applied to etch a sloping surface in the sidewalls of the via cavity. A second vertical anisotropic dry etch process is then applied to extend the sloping sidewalls of the via cavity down to a substrate of the semiconductor device. The smooth sloping surfaces of the sidewalls are formed without a prior art concave surface of the type that interferes with a via fill process.