Metal redundant graph drawing method for improving CMP morphology

Abstract

The invention provides a metal redundant graph drawing method for improving CMP morphology. The method comprises the steps that a complete design layout of metal, through holes and all clearance layers is acquired; irregular regions allowing addition of metal redundant graphs are drawn through layout logic operation, and the irregular regions are expanded respectively to be rectangular regions; the metal redundant graphs with fixed sizes and relative positions are added with a lower left point of each region allowing addition being a starting point, and temporary graphs, waiting for post-processing, of the metal redundant graphs are formed; the temporary graphs of the metal redundant graphs are post-processed, including forbidding of addition or deletion or merging of region receding edges, extension of short edges, removal of small-sized graphs violating design rules, truncation of overlong graphs and other logic operation processes; and the post-processing logic operation processes are executed cyclically, and a final metal redundant graph layout is obtained after no error is found through checking according to the design rules. Through the method, the problems of poor surface uniformity and bad flatness caused by insufficient metal density can be better solved.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, and in particular to a metal redundancy pattern drawing method for improving CMP morphology. Background technique [0002] In addition to reflecting the logic or function of the circuit to ensure that the layout schematic (LVS check, Layout Versus Schematic Check) is verified correctly, the integrated circuit layout also needs to add some graphics that are not related to LVS verification to reduce the deviation of the process. These graphics we Call it a redundant graph (dummy). Normally, considering the surface uniformity caused by insufficient etching or excessive etching during etching and the poor flatness of the wafer surface after the chemical vapor polishing (CMP) process, the metal density must meet Density requirements specified in design rules. The addition of metal dummy patterns is widely used to adjust the density of metal in local areas, thereby improv...

AI Technical Summary

Problems solved by technology

[0005] The present invention proposes a method for drawing metal redundant graphics to improve CMP morphology, which can better solve the problems of poor surface uniformity and poor flatness caused by insufficient metal density

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