PATTERNING CHARACTERISTICS OF HOLE PATTERNS IN SYNCHROTRON-RADIATION LITHOGRAPHY

The patterning characteristics of synchrotron radiation lithography fo r hole patterns using a low-contrast mask (contrast: 3.5) are investig ated. A resolution of 110 nm provides a large exposure dose latitude o f more than 10% when the proximity gap is less than 15 mu m, and the r eplicated minimum hole size is 70 nm with a 10-mu m gap. Resist patter n sizes from 110 to 360 nm are kept within +/-10% with proximity gaps of less than 20 mu m. However, the exposure dose margin to guarantee m ask linearity decreases to several percent because of the different op timum exposure dose for each pattern. Pattern size correction using ma sk bias to improve the mask linearity and exposure dose margin is prop osed.