Thermal characterization of materials for double patterning
Among the different possibilities for sub-40nm half-pitch devices, double patterning (DP) is one of the most promising candidates. This paper is related to the double imaging approach where the first lithographic step is followed by a resist curing to avoid any degradation of the pattern during the upper-layer resist patterning. In this paper we develop a methodology based on thermal analysis measurements to demonstrate the existence of an optimal curing temperature. The results are in good agreements with the lithographic observations showing that thermal characterization of the resist is a complementary source of information for the DP process. Moreover, we were able to provide valuable information on the evolution of the properties of the resist occurring during the curing step and some directions for next generation curing resists.
double patterning curing thermal analysis lithography photoresist