VIA STRUCTURE AND VIA ETCHING PROCESS OF FORMING THE SAME

摘要

PURPOSE: A via structure and a via etching method thereof are provided to improve the via side wall coverage for deposition process by implementing the undercut trimming process after the via etching process. CONSTITUTION: A hard mask layer(15) is formed on a semiconductor substrate(10). A photoresist layer(18) is formed on the hard mask layer. A first opening is formed by patterning the photoresist layer. A second opening is formed under the first opening by patterning the hard mask layer. A via is formed to pass through at least a part of the semiconductor substrate.