一种可以正负互用的水型化学增幅抗蚀剂的研究

Image Reversal Techniques with a Water-based Chemical Amplified Photoresist

研究了一种由甲酚醛树脂、六甲氧基甲基三聚氰胺 (HMMM)、六氟磷酸根二苯碘盐和光敏剂组成的水型紫外化学增幅抗蚀剂 ,发现二苯基碘盐不仅可以作为光敏产酸物 ,而且可以作为阻溶剂 .用碘盐作为光敏产酸物 ,光解产生的酸可以在中烘时催化甲酚醛树脂与 HMMM的交联反应 ;用氢氧化钠 -乙醇水溶液显影可以得到负性光刻图形 ;采用碘盐作为阻溶剂 ,可阻止非曝光区的胶膜溶解在显影液中 ,用稀的氢氧化钠水溶液显影可以得到正性光刻图形 .通过优化后的光刻工艺条件 ,采用不同的显影液和光刻工艺流程 ,实现了同一光致抗蚀剂的正负性反转 ,并分别得到负性和正性光刻图形 .

A water-based chemical amplified photoresist, which is composed of Novolak resin, hexamethoxylmethyl melamine(HMMM), diphenyliodonium salt and photosensitizer was investigated. It was found that the diphenyliodonium salt can act not only as the photosensitive acid generator, but also as the dissolution inhibitor. As a photosensitive acid generator, the diphenyliodonium salt can generate acid after exposure, which catalyzes the condensation of Novolac-HMMM system in post-exposure bake step. Using the alkali-ethanol aqueous solution as the developer the photoresist can be of negative tone. As a dissolution inhibitor, the diphenyliodonium salt can prevent the unexposure film from being dissolved in the developer. Therefore, using the dilute alkali aqueous solution as developer this photoresist can be of positive tone. Image reversal can be achieved by selecting different developer and different photographic process. The negative tone image and the positive tone image were obtained by the optimized photolithographic parameters.