A Dummy Synthesis Method Based on Density Gradient Hotspot Clustering and Local Solving

Abstract

The invention belongs to the field of manufacturability design of semiconductors and particularly relates to a dummy comprehensive optimization method considering density gradient constraints for the copper-connection dummy metal filling technology. According to the method, the upper limit and lower limit constraints and the density gradient constraints are applied at the same time in the dummy comprehensive process, and the dummy insertion number is minimized. According to the method, the inhibiting effect on technological deviation of chemical-mechanical polishing, photoetching and the like are fully considered. The method solves the dummy comprehensive problem considering the gradient constraints on the basis of the covering linear programming, hot spot cluster grouping and linear programming local solving method and lowers the time complexity of the problem to O(n2logn). Compared with an existing method, the dummy comprehensive optimization method well achieves trade-off between the calculating precision and the executing efficiency and is a feasible method for solving large-scale dummy comprehensive problems.

Description

technical field [0001] The invention belongs to the technology for copper interconnect dummy metal filling in the field of semiconductor manufacturability design, and specifically relates to a dummy comprehensive optimization method that considers density gradient constraints and uses gradient hotspot clustering grouping and local solution technology. Background technique [0002] The development of the integrated circuit industry is an important driving force to promote the progress of social informatization. As the integrated circuit manufacturing process enters the nanometer scale, more and more serious process deviations affect the performance and yield of chips. Manufacturing deviations produced by processes such as chemical mechanical polishing (CMP: Chemical Mechanical Planarization) and photolithography obviously show a dependence on layout patterns (Pattern Dependent). The CMP process will produce dishing (Disshing) and erosion (Erosion) defects [1, 2] on the surfa...

AI Technical Summary

Problems solved by technology

This method imposes gradient constraints on the grid, which greatly simplifies the dummy filling problem, but partially loses the physical connotation

And from the effect point of view, this method leads to too many dummy insertions due to the lack of control over the number of dummy insertions

In addition, the literature [16] proposes a dummy synthesis method similar to the gradient constraint, which is similar to the Lipchitz-like constraint, but this method also does not consider the limitation of the number of dummy insertions, and still uses the traditional linear programming method. solution, so the computational complexity is high

[0007] Furthermore, in the existing dummy synthesis algorithms, it is generally assumed that the density and density gradient hotspots (that is, the regions that violate the gradient constraints) of the graphics are randomly distributed, and the characteristics of the distribution of layout graphics have not been considered.

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