Low-temperature fabrication of fine structures on glass using electrical nanoimprint and chemical etching

Periodic structures were imprinted on a soda lime glass surface below its glass transition temperature (T_g) using a carbon-coated SiO₂ mold under application of DC voltage. The structure height increased with the applied DC voltage, although no significant increase with pressure was found. At a temperature around T_g, the height reached saturation. Chemical etching using 55% KOH solution at 70 °C increased the structure height to eight times the height before etching. Noticeable alternating depression patterns and rapid chemical etching are closely related with the selective decrease in sodium concentration, which occurred only in the surface areas that were pressurized by the mold.