Blob defect solution for 28 nm hole pattern in 193 nm topcoat-free immersion lithography

In this paper, we studied the blob defect arising in the development of 193 nm topcoat-free immersion lithography for 28 nm node hole-pattern and we discussed the root cause of blob defect fundamentally. Finally, we found changing the content of hydrophobic addictive in topcoat-free resist could reduce the dynamic receding contact angle and then could eliminate the blob defect effectively.