Abstract
This study describes the recent progress of negative-tone imaging with EUV exposure (EUV-NTI) compared with positive-tone development (PTD). NTI uses organic solvent-based developer to provide low swelling and smooth- dissolving behavior. Therefore, EUV-NTI is expected to offer several advantages in terms of performance, especially for improving line-width roughness (LWR), which is expected to resolve the resolution, LWR, and sensitivity (RLS) trade-off. Herein, novel chemical amplified resist materials for EUV-NTI are investigated to improve LWR and sensitivity. Results indicate that the EUV-NTI has better performance than PTD, while maintaining the LWR performance. The novel high sensitivity formulation, with ‘single digit mJ/cm2 photo speed’, resolved 22-nm half pitch using NXE3100 scanner. Furthermore, EUV-NTI processing such as the pre-applied bake (PAB) temperature, post-exposure bake (PEB) temperature, development procedure, and rinse procedure are very effective for improving the lithographic performance. In addition, the lithographic performance with NXE3100 scanner is also reported..
