The molecular size of an alkaline cation has been reported to affect the dissolution of resist film in an alkaline aqueous solution. However, the details are still unclear. In this study, the dissolution dynamics of poly(4-hydroxystyrene) (PHS) in potassium hydroxide (KOH) and sodium hydroxide (NaOH) aqueous solutions were investigated to clarify the effects of small alkaline cations on the dissolution dynamics of typical backbone polymer for chemically amplified resists by a quartz crystal microbalance (QCM) method. The temporal changes in the frequency and impedance of QCM substrates during development were measured. The maximum impedance reachable during development significantly exceeded that of the developer saturated with PHS, unlike the case of tetramethylammonium and tetraethylammonium cations. This means that the PHS matrix near the surface was swollen by decreasing the size of the alkaline cation. By either increasing or decreasing the size of the alkaline cation from tetramethylammonium and tetraethylammonium cations, the transient swelling layer became thick.

中文翻译：

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通过石英晶体微天平（QCM）方法研究聚（4-羟基苯乙烯）在氢氧化钾（KOH）和氢氧化钠（NaOH）水溶液中的溶解动力学

据报道，碱性阳离子的分子大小会影响抗蚀剂膜在碱性水溶液中的溶解。但具体细节仍不清楚。在本研究中，研究了聚（4-羟基苯乙烯）（PHS）在氢氧化钾（KOH）和氢氧化钠（NaOH）水溶液中的溶解动力学，以阐明小碱性阳离子对典型主链聚合物溶解动力学的影响通过石英晶体微天平 (QCM) 方法进行化学放大抗蚀剂。测量了 QCM 基板在开发过程中频率和阻抗的时间变化。与四甲基铵和四乙基铵阳离子的情况不同，显影期间可达到的最大阻抗显着超过用PHS饱和的显影剂的阻抗。这意味着表面附近的 PHS 基质因碱性阳离子尺寸的减小而膨胀。通过增加或减少四甲基铵和四乙基铵阳离子中碱性阳离子的尺寸，瞬时膨胀层变厚。