20 March 2006 Line end optimization through optical proximity correction (OPC): a case study
Author Affiliations +
Abstract
Device performance is highly associated with the line end performance of critical layers. Poly line end shortening (LES) or bridging can result in leakage or short circuit. Model-based optical proximity correction (OPC) prioritized to fit one-dimensional pitch structures can also improve two-dimensional line end performance. However, it may still fail without meeting the line end bridging margin or minimum line end length requirements. A leakage problem has been observed, when poly gate line end shortening occurs, following the use of an OPC recipe chosen to be a compromise for the line end bridging problem. In this paper, several approaches related to OPC are studied on poly layer, in terms of line end bridging margin and line end shortening, to optimize line end performance. The OPC minimum external constraint is optimized to meet both line end bridging and shortening requirements. Serif type line end provides the OPC model with more flexibility to pull back the center segment between line end serifs and improves the bridging margin by 2%, with negligible sacrifice on line end length under overexposure conditions. No effect is seen on the bridging margin with different segment lengths of center pull back at the serif line end. Bridging margin can be improved dramatically (6%) by adding SRAF, due to the increase of aerial image intensity in the line end space. Finally, the OPC model fitting for line end shortening is briefly described and a post-correction rule-based OPC is introduced to improve the line end shortening. Handcrafted OPC is also used for this case study for few structures that need extra correction to achieve enough line end length.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Dyiann Chou, Ken McAllister, "Line end optimization through optical proximity correction (OPC): a case study", Proc. SPIE 6154, Optical Microlithography XIX, 61543A (20 March 2006); doi: 10.1117/12.651455; https://doi.org/10.1117/12.651455
PROCEEDINGS
12 PAGES


SHARE
Back to Top