Method for proximity effect compensation on alternative phase-shift masks with bias and optical proximity correction

Abstract

A method of forming an alternative phase shifting mask and forming a circuit pattern on a wafer using the mask are described. Optical proximity correction is added to a data file, in which a description of a circuit pattern has been stored, to obtain a first modified data file. The first modified data file is then separated into a second modified data file, for regions of the mask having dense line/space patterns, and a third modified data file, for regions of the mask having isolated line space patterns. Critical dimension bias is then added to the second modified data file forming a fourth modified data file. The third modified data file and the fourth modified data file are then merged into a single fifth modified data file. The fifth modified data file is then is then converted to an alternative phase shift data file. An alternative phase shift mask is then formed from the alternative phase shift data file. The alternative phase shift mask has then been corrected for optical proximity effect and critical dimension bias has been added. This alternative phase shift mask can then be used in forming the circuit pattern on an integrated circuit wafer.

Dependencies are inferred from the claim text.