Fabrication method for forming rounded corner of contact window and via by two-step light etching technique

摘要

The present invention generally relates to provide a fabrication method for forming a rounded corner of a contact window or a via by using a two-step light etching technique. In the present invention, after the etching process to form the contact window or the via, an object of the invention is to utilize oxygen plasma and fluorocarbon plasma of the two-step light etching technique to produce the rounded corner of the window or via so as this rounded opening profile of the contact window or the via can supply for following metal-filling processes.