70-nm contact hole pattern with shrink technology

Abstract

The present paper demonstrates the applicability of thermal flow resist to print sub-0.1micrometers contact holes using 248nm lithography. With the thermal flow resist, 200nm contact holes were defined by KrF lithography system. Then following one step thermal flow resulted in down to 70nm contact holes with vertical sidewall profile. The main feature of the thermal flow resist is one step process having the linear dependency of flow rate on baking temperature. As the results, thermal flow resists pattern shrinkage controlled by post development baking temperature. Resist flowing occurred post development temperature was higher than Tg. Baking temperature was not the dominant factor from the contact hole shrinkage size curve. The thermal flow process using the thermal flow resist is a promising candidate for the fabrication of gigabit devices.