ArF photoresist containing novel acid labile cross-linker for high contrast and PED stability

Abstract

In our previous model, we have introduced a lot of t- butylcarboxylate group in matrix resin to achieve a high contrast and obtain a good lithographic performance. Most ArF photoresists having only t-butylcarboxylate group as a dissolution inhibitor have showed by far the inferior performance in a poor amine controlled environment. To overcome this problem, we greatly reduced the usage of t-butyl carboxylate group and increased the amount of HMEBC that contains both carboxylic acid group and alcohol group. And also, we newly introduced acid labile cross-linker for high contrast. Our novel resist exhibited an excellent lithographic performance without any protective top coating material, namely, a good PED (post exposure delay) stability, an improved CD (Critical Dimension) linearity, a proper sensitivity for process, and a good contrast. In addition, its synthetic yield is very high (&gt;50%) and then it is cost- effective for mass production. 120 nm patterns were successfully defined at 13 mJ/cm<SUP>2</SUP> by using a BIM (Binary Intensity Mask) with 2/3 annular (0.50/0.75(sigma) ).