Scatterometry analysis of sequentially imprinted patterns : Influence of thermal parameters
Résumé
Scatterometry technique has been used to characterize Thermal Step and Repeat NIL processes in the framework of NAPANIL project. Two hundred and fifty nanometers dense lines were imprinted in mr-7030 polymer and their profiles have been analyzed and compared to the mold one. It has been demonstrated that scatterometry on silicon exhibits a very high accuracy and that a change of the sidewall verticality of only few degrees can been measured. The results show that some reflow occurs in lines during the imprint of neighboring dies due to heat diffusion. This phenomenon has been studied as a function of printing temperature, demolding temperature, and space between adjacent dies. The conclusion is that a trade off has to be made between imprint temperature and chuck temperature to be able to fill mold cavities with a limitation of the reflow.