Hello Matthias,
Thanks for all your hard work (and everyone else involved) to make such a useful, free tool.
I'm interested in RBA scripts for calculating and plotting effective local pattern density for a given layout and technology file. The technology file would specify the unit cell size for which to determine the local density and any models/filters for weighting the data within a cell.
The effective local pattern density information could then be used to help designers choose a better dummy fill density, or fed into an algorithm that optimizes their generation; all in order to improve process uniformity.
Perhaps something very basic could be put together using the clip tool, calc area tool, and tiling utility.
Any thoughts?
John-Rolf
Comments
Hi JRO,
actually that's possible. I have included a script below which demonstrates that. The parameters of the density map are coded into the script currently. The script can be extended to read those parameters from a file or compute them from the cell's bounding box.
The script outputs the density as an image overlay. Black is for density 0 and white for density 100%. You can adjust the colors by double-clicking on the image and choosing other colors in the data mapping tab. It should be easy to extend the script to write some report file or similar.
Please note that the performance is somewhat limited due to performance limitations of the scripting language and the flat merge operation. Commercial tools are faster by an order of magnitude. I was however able to derive the density map with the parameters shown from a metal layer of a 1.5G (50 square mm) test layout in approximately 5 minutes with a window size of 50x50 micron.
Best regards,
Matthias