An up-stream design auto-fix flow for manufacturability enhancement

Abstract

Although many physical limitations have been reached in modern micro-lithography, printed critical dimensions continue to shrink according to the International Technology Roadmap for Semiconductors (ITRS) [1]. To meet the demands imposed by this guideline, the traditional separation between design and manufacturing communities is being bridged. Many EDA tools package manufacturing data for delivery into established simulation engines for design verification. However, none of them provide practical implementations of design optimizations at an early stage in the design flow.This paper presents an automated layout modification flow for metal layers with the goal of enhancing manufacturability. It can easily be deployed in a current custom design flow in a way that is visible to designers. The result of this scheme is improvements to process windows and yield, while minimizing circuit performance detractors. The flow is verified through analyses of both the impact on circuit performance and the benefit to manufacturability. It has been implemented in a state-of-the-art 65 nm chip design. Both silicon yield and electrical performance data are currently being collected and analyzed.

Lithography friendly routing: From construct-by-correction to correct-by-construction

“…ing [35] and widening [36], improvement of via metal overlap, wire and jog widening [37], simultaneous wire spreadingwidening-filling [38] and more [36], [39]. Usually these postrouting optimizations are applied in an iterative manner until there is no improvement.…”

Correcting lithography hot spots during physical-design implementation

“…The use of rules in a multi-stage detection scheme, to pre-filter the layout for model-based detection, was presented by Mukherjee et al [2], again without correction guidance. Automatic correction of design-rule-check (DRC) violations was presented by Yang et al [3] but without confirmation by model-based detection, which raises the issue of side effects from unnecessary fixes. Rule-based correction of Hot Spots for contact holes was shown by Lucas et al [4], again without model-based detection.…”