EUV-mask pattern inspection using current DUV reticle inspection tool

Abstract

EUV mask pattern inspection was investigated using current DUV reticle inspection tool. Designed defect pattern of 65nm node and 45nm node were prepared. We compared inspection sensitivity between before buffer etch pattern and after buffer etch pattern, and between die to die mode and die to database mode. Inspection sensitivity difference was not observed between before buffer etch pattern and after buffer etch pattern. In addition to defect inspection, wafer print simulation of program defect was investigated. Simulation results were compared to inspection result. We confirmed current DUV reticle inspection tool has potential for EUV mask defect inspection.

Mask readiness for EUVL pilot line

“…EUV dedicated mask infrastructures, especially defect inspection, repair and re-qualification tools have been developing mostly through global consortia, such as SEMATECH in US, Selete and EIDEC in Japan [4][5] [6]. Before those tools will be released to the production market, we may use the tools with extended current technologies as bridge tools.…”

Residual-type mask defect printability for extreme ultraviolet lithography

“…However, the path to establish the EUVL is not without technical difficulties, e.g., lack of sufficient light-source power, particle-free mask handling, defect-free and flat mask blanks, [1][2][3][4] and resist material development, and need to be resolved. From the viewpoint of EUV mask fabrication, mask pattern defect inspection [5][6][7] and repair [8][9][10][11][12][13] are some of the most demanding tasks to be addressed. The reason is that for EUVL generation, the device pattern feature size happens to be exceedingly small and calls for higher repairing accuracy than would be required in optical lithography.…”

Critical dimension variation caused by wrinkle in extreme ultra-violet pellicle for 3-nm node

“…However, a low-power source and defect control are important issues that must be solved before the 5-and 3-nm processes can be used in high-volume manufacturing. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Among these problems, controlling the number of defects is probably the most important, as the defects on the EUV mask induce errors in the patterns and therefore result in a loss in the product yield. An EUV pellicle is employed to protect the EUV mask from contamination and particles during the exposure process.…”