Method for forming copper wiring in a semiconductor device

摘要

A process for forming a copper wiring and the prevention of copper ion migration in a semiconductor device is disclosed herein. The process includes conducting a post-cleaning process for a copper layer that is to form the cooper wiring after already having undergone a CMP process. The post-cleaning process includes conducting a primary chemical cleaning using a citric acid-based chemical. A secondary chemical cleaning is then conducted on the copper layer having undergone the primary chemical cleaning using an ascorbic acid-based chemical. After the post-cleaning process is completed, the migration of copper ions over time is prevented thereby improving the reliability of the semiconductor device.