Etching mechanism and pattern size controlling method in imprint template fabrication for MEMS

To improve the accuracy of etched pattern size controlling in imprint template fabrication process based on glass wet etching, the reaction kinetic mechanism of the soda-lime glass dissolution process in aqueous HF-based solution was studied and the dominant active component(HF) ₂in etching agent was identified. Based on the combination of mechanism analysis and etching experiments, a reasonable theoretical model of etching rate was established. Experiments in etchants with various concentrations of hydrofluoric acid were carried out and the comparison of the etching rate data between experiments and the theoretical model calculation showed that the prediction accuracy was higher than 96%. Imprint template fabrication experiments in which the etching time was determined according to the etching rate model were performed and the template with a pattern feature size of 15 μm and a depth of 8 μm was demonstrated. The etched pattern size was measured with a profiler, which indicated that the etched size prediction error based on the established etching rate model was only 0.05 μm.