RELACS technique for printing sub-100nm trench using KrF lithography

For some sub-0.15um FLASH process, sub-100nm trench, which is the smallest critical dimension to be resolved, becomes a real challenge to conventional KrF lithography. RELACS (resolution enhancement lithography assisted by chemical shrink) process, utilizing the cross-linking reaction catalyzed by the acid in the patterned resist, is originally developed to enhance the resolution for contact hole in DRAM process. Due to its simplicity and robustness, it is viable to be explored for other device features. This paper demonstrates the application of RELACS technique for printing sub-100nm trench using KrF lithography.