Fully automatic side lobe detection and correction technique for attenuated phase-shift masks

Using a new functionality of the Calibre PrintImage tool, a method for side lobe correction is presented. A full chip aerial image mapping is first obtained and then analyzed to detect and output polygons corresponding to chip areas where the aerial image intensity is above a user set threshold. Using state of the art DRC tool and associated RET software from Mentor Graphics we are able to propose a completely automated flow for side lobe detection and correction. Mask manufacturing complexity can also be taken into consideration using geometrical constraints similar to those used for scattering bars, such as minimum length, minimum width and minimum space to main features.