Abstract

A process for ablation etching through one or more layers of dielectric materials while not etching an underlying conductive material layer comprises selecting parameters whereby the ablation process automatically stops when the conductive material layer is reached, or monitoring the process for end point detection of the desired degree of ablation. Parameters selected are the absorptivity of the dielectric layer versus that of the conductive material layer. End point detection includes monitoring radiant energy reflected from the workpiece or the content of the materials being ablated from the workpiece.

Primary Examiner: Vargot; Mathieu D.
Attorney, Agent or Firm: Braden; Stanton C.