Atomic force microscope anodization lithography using a triarylsulfonium salt photoinitiator

Photoacid generators (PAGs) have been widely used as a key component in the development of chemically amplified photoresist. In this study, a PAG with good thermal stability and an electron-withdrawing group was applied to AFM anodization lithography. Specifically, triarylsulfonium salts (TAS) such as a diphenyl(4-tert-butoxycarbomethoxyphenyl)-sulfonium triflate (DTCPS-Tf) and triphenyl-sulfonium triflate (TPS-Tf) were used successfully to fabricate anodized nanostructures by AFM anodization lithography. In addition, the effect of electron-withdrawing materials and optimized lithographic conditions were studied through a systematic alteration of lithographic factors such as applied voltage, lithographic speed, and humidity.