Development of underlayers for MOR sensitivity improvement

Metal Oxide Resists (MORs) are known for achieving high resolution which allows them to be a highly attractive choice for next-generation semiconductor manufacturing. To further address the advantages of MORs, underlayers are introduced to improve the compatibility between the MORs and a substrate, mitigate unfavorable pattern failures, and increase sensitivity. In this work, we discuss the potential of improving MOR sensitivity by increasing photoresist activation at the bottom while reinforcing against pattern collapse. The influence of underlayers on MORs was evaluated using an NXE3400B EUV exposure system to print the 14 nm HP line-space feature. Therefore, a dose modifier and performance modifier were incorporated into underlayers to interact with photoresists and facilitate MOR solubility switch. The results identified an effective dose reduction of ~20%, indicating the effect of underlayers on the photoresist solubility switch.