Patent ID: 6183916
Filing Date: 2001-02-06
Classification: G03F

Abstract:
A method of forming phase shifting masks, comprising:storing a description of a circuit pattern in a data file, wherein said circuit pattern has dense line/space regions, having lines with a first linewidth on a first pitch, and isolated line/space regions, having lines with a second linewidth on a second pitch;applying an Optical Proximity Correction to said data file thereby forming a first modified data file;separating said first modified data file into a second modified data file and a third modified data file, wherein said second modified data file contains data relating to said dense line/space regions and said third modified data file contains data relating to said isolated line/space regions;adding a critical dimension bias to said second modified data file thereby forming a fourth modified data file;merging said third modified data file and said fourth modified data file into a fifth data file;converting said fifth data file into a phase shifting mask data file; andforming a phase shifting mask using said phase shifting mask data file.