Double Patterning Analysis Method by Emulation Using a Double-Exposure Technique

Abstract

Double patterning lithography was utilized to break the resolution limit of lithography and is the most promising technology that enables shrinking of this limit. There are some barriers concerning evaluation of the double patterning process because it includes the hard mask fabrication and dry etching process. We proposed a new evaluation method for double patterning to analyze photomask performance with an easy and simple procedure using a double-exposure technique. Results showed this emulation method was useful in determining the impact of mask overlay and critical dimension (CD) error on double patterning lithography. We also evaluated the impact of mask overlay and CD. Both the overlay and CD difference were very good between the two masks. Correlations between mask and wafer cannot be detected because of the measured overlay error and the CD performance of masks was too small.