Comparison of fast 3D simulation and actinic inspection for EUV masks with buries defects
Aerial images for isolated defects and the interactions of defects with features are compared between the Actinic Inspection Tool (AIT) at Lawrence Berkeley National Laboratory (LBNL) and the fast EUV simulation program RADICAL. Comparisons between AIT images from August 2007 and RADICAL simulations are used to extract aberrations. At this time astigmatism was the dominant aberration with a value of 0.55 waves RMS. Significant improvements in the imaging performance of the AIT were made between August 2007 and December 2008. A good match will be shown between the most recent AIT images and RADICAL simulations without aberrations. These comparisons will demonstrate that a large defect, in this case 7nm tall on the surface, is still printable even if it is centered under the absorber line. These comparisons also suggest that the minimum defect size is between 1.5nm and 0.8nm surface height because a 1.5nm defect was printable but a 0.8nm was not. Finally, the image of a buried defect near an absorber line through focus will demonstrate an inversion in the effect of the defect from a protrusion of the dark line into the space to a protrusion of the space into the line.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Materials Sciences Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 950223
- Report Number(s):
- LBNL-1645E; TRN: US200910%%126
- Resource Relation:
- Conference: SPIE advanced lithography 2009, San Jose, CA, February 22-27, 2009
- Country of Publication:
- United States
- Language:
- English
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