A sulfonium salt having a triphenylsulfonium cation and a sulfite anion within the molecule is best suited as a photoacid generator in chemically amplified resist compositions. Upon exposure to high-energy radiation, the sulfonium salt generates a sulfonic acid, which facilitates efficient scission of acid labile groups in chemically amplified positive resist compositions. Because of substantial non-volatility under high vacuum conditions in the EB or EUV lithography, the risk of the exposure tool being contaminated is minimized.
分子中含有三苯基磺鎓阳离子和亚
磺酸盐阴离子的磺鎓盐是
化学增感抗蚀剂组合物中最适合用作光酸发生剂的。在高能辐射的照射下,磺鎓盐会产生
磺酸,从而促进
化学增感正向抗蚀剂组合物中酸不稳定基团的高效裂解。由于在EB或EUV光刻术中高真空条件下具有相当的非挥发性,因此减少了曝光工具被污染的风险。