Negative-Tone Imaging (NTI) for Advanced Lithography With EUV Exposure to Improve ‘Chemical Stochastic’

Extreme ultraviolet (EUV) lithography is almost ready for realize 7nm generation manufacturing and beyond. A key factor for the realization of EUV lithography is the choice of EUV resist materials that are capable of resolving below 15nm half pitch with high sensitivity. However, the performance of EUV resist materials is still not enough for the true HVM requirements. One critical issue is `Chemical stochastic', which will be become `defectivity'. We report herein to improve of `Chemical Stochastic' by using negative-tone imaging (NTI) process with EUV exposure. Also, the other options will be introduced.