Novel Oxygen-based Dry Strip Process Reducing NOx Emissions During Photoresist Removal

Industrial interest in NO
_x
emissions from dry strip process using O
₂
/N
₂
downstream plasma has been significantly increased. In this article, we compared strip performances and NO
_x
emissions for recipes with different total gas flow rate and nitrogen ratio. When total gas flow rate and nitrogen ratio are lowered, NO
_x
emissions were reduced and strip performances, such as strip rate, within-wafer uniformity, wafer-to-wafer uniformity, were achieved. For both qualitative and quantitative analysis, an optical emission spectroscope on the chamber and a portable gas analyzer on the dry pump were used, respectively. The results of both analyzes were well matched to demonstrate NO
_x
emissions from the various recipes. In conclusion, > 12.3 μ/min of strip rate, <; 5.1% of within-wafer uniformity, 1.4% of wafer-to-wafer uniformity, and 3,414 of NO
_x
emissions can be achieved from the newly proposed recipe.