Studies on the interfacial etching reaction of development-free vapor photolithography

Development-free vapor photolithography (DFVP) is an all-dry pattern transf er technique, which is based on the reaction of SiO2 with HF vapor under a polymer film in the presence of catalysts, called accelerators, at a temper ature above 100 degrees C. This article reports that both organic bases and superacids can catalyze this interfacial etching reaction. When organic ba ses are used as the accelerator, the etching mechanism is bimolecular nucle ophilic substitution (S(N)2), while the superacid-catalyzed etching reactio n undergoes a unimolecular nucleophilic substitution (S(N)1) mechanism. Ins ight gained from this study provides guidance for the development of mon se nsitive accelerator systems. Now, this novel microlithographic technique is being successfully applied to the manufacture of power electronic devices. (C) 1999 American Vacuum Society .