Studies of Wafer Backside Micro-arcing Prevention In Encore Ta Process

In advance Cu BEOL process, Encore Ta/TaN deposition process is widely used for barrier layer deposition to achieve lower via resistance and better electro migration and stress migration performance. However, wafer micro arcing existed frequently due to complex chamber design and DC/RF/AC/ESC adoption in Encore Ta process. To solve the micro arcing issue is the one of key topics in Encore Ta process. In this study, the formation mechanism of micro arcing is analyzed. Gas plug is introduced into Encore Ta process to prevent micro arcing.