Novel fluorohydroxyalkyl sulfonate salts and derivatives, photoacid generators, resist compositions, and patterning process

摘要

Sulfonate salts have the formula: CF₃-CH(OH)-CF₂SO₃^-M⁺ wherein M⁺ is a Li, Na, K, ammonium or tetramethylammonium ion. Because of inclusion within the molecule of a hydroxyl group which is a polar group, the sulfonic acids are effective for restraining the length of acid diffusion through hydrogen bond or the like. The photoacid generators that generate these sulfonic acids perform well during the device fabrication process including coating, pre-baking, exposure, post-exposure baking, and developing steps. The photoacid generators are little affected by water left on the wafer during the ArF immersion lithography.