12 March 2008 Checking design conformance and optimizing manufacturability using automated double patterning decomposition
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Delays in equipment availability for both Extreme UV and High index immersion have led to a growing interest in double patterning as a suitable solution for the 22nm logic node. Double patterning involves decomposing a layout into two masking layers that are printed and etched separately so as to provide the intrinsic manufacturability of a previous lithography node with the pitch reduction of a more aggressive node. Most 2D designs cannot be blindly shrunk to run automatically on a double patterning process and so a set of guidelines for how to layout for this type of flow is needed by designers. While certain classes of layout can be clearly identified and avoided based on short range interactions, compliance issues can also extend over large areas of the design and are hard to recognize. This means certain design practices should be implemented to provide suitable breaks or performed with layout tools that are double patterning compliance aware. The most striking set of compliance errors result in layout on one of the masks that is at the minimum design space rather than the relaxed space intended. Another equally important class of compliance errors is that related to marginal printability, be it poor wafer overlap and/or poor process window (depth of focus, dose latitude, MEEF, overlay). When decomposing a layout the tool is often presented with multiple options for where to cut the design thereby defining an area of overlap between the different printed layers. While these overlap areas can have markedly different topologies (for instance the overlap may occur on a straight edge or at a right angled corner), quantifying the quality of a given overlap ensures that more robust decomposition solutions can be chosen over less robust solutions. Layouts which cannot be decomposed or which can only be decomposed with poor manufacturability need to be highlighted to the designer, ideally with indications on how best to resolve this issue. This paper uses an internally developed automated double pattern decomposition tool to investigate design compliance and describes a number of classes of non-conforming layout. Tool results then provide help to the designer to achieve robust design compliant layout.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Chris Cork, Chris Cork, Brian Ward, Brian Ward, Levi Barnes, Levi Barnes, Ben Painter, Ben Painter, Kevin Lucas, Kevin Lucas, Gerry Luk-Pat, Gerry Luk-Pat, Vincent Wiaux, Vincent Wiaux, Staf Verhaegen, Staf Verhaegen, Mireille Maenhoudt, Mireille Maenhoudt, } "Checking design conformance and optimizing manufacturability using automated double patterning decomposition", Proc. SPIE 6925, Design for Manufacturability through Design-Process Integration II, 69251Q (12 March 2008); doi: 10.1117/12.774647; https://doi.org/10.1117/12.774647


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