Automated Layout Correction for Full Feature Phase Shifting Mask (PSM)
Publication Date: 2002-Nov-11
The IP.com Prior Art Database
A tool for checking and classifying possible errors in a layout to be phase shifted is described. By placing error markers in the layout, a phase shifting engine can be run more quickly and with fewer errors. In some instances, the markers may indicate that a region should be handled on the complementary mask rather than the phase shifting mask to alleviate problems.
1. Descriptive Title
Automated layout correction for full feature PSM.
Current methodology is to apply the PSM creation on the poly layer or critical layer and then study the error and manually fix the polygon to make it non-critical and then apply PSM shifter creation and coloring. This is very tedious and needs a PSM expert to debug the problems and either a mask designer or layout expert to change the layout or mark areas non-critical.
We have used a PSM error classification tool psmLint to classify the various checks before applying PSM solution. Then we have written special layout correction algorithm for some of these error markers to sacrifice some of the critical polygon automatically and thus creating a layout, which will not have a large number of shifter creation and coloring errors. Hence we have done the following -
1. Classify the various potential PSM placement and coloring errors.
2. Automated the expert knowledge to correct these problems based on the markers.
3. Removed the iteration through expensive shifter creation and coloring process to correct the layout problem upfront(floorplanning).
4. Made these corrections push button, (without manual intervention) based on technology data.
We are presenting the number of corrections that have been made automated in the attached diagrams. These corrections were made for a customer's full feature PSM solution.
The corresponding type of errors were detected and corrected -
1. End-edge interfering with end-edge leading to inversed T. Corrections are nu...