Spatial scaling metrics of mask-induced induced line-edge roughness
Mask contributors to line-edge roughness (LER) have recently been shown to be an issue of concern for both the accuracy of current resist evaluation tests as well the ultimate LER requirements for the 22-nm production node. Problems arise from mask absorber LER as well as mask reflector or surface roughness leading to random phase variations in the reflected beam. Not only do these mask contributors effect to total measured LER in resist, but they also effect LER spatial characteristic such as the LER power spectral density and related descriptors of correlation length and roughness exponent. Noting that these characteristics are important in the understanding of LER, it is crucial to understand how mask effects impact these parameters. Moreover, understanding how these metrics respond to mask effects may lead to an experimental mechanism for experimentally evaluating the importance of mask contributors to LER. Here we use computer modeling to study the LER spatial metrics arising from mask effects. We further describe the effects of illumination conditions and defocus on the metrics and compare the results to those expected from intrinsic resist LER.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- Materials Sciences Division
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 940775
- Report Number(s):
- LBNL-992E
- Journal Information:
- Journal of Vacuum Science and Technology B, Journal Name: Journal of Vacuum Science and Technology B
- Country of Publication:
- United States
- Language:
- English
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