Efficacy of low etch rate in achieving nanometer-scale smoothness of Si (1 0 0) and (1 1 0) plane surfaces using KOH and KOH/IPA solutions for optical mold applications
This paper reports on the efficacy of low etch rate in achieving nanometer-scale smoothness of Si (1 0 0) and (1 1 0) plane surfaces etched with various conditions of concentrations and temperatures of KOH and KOH/IPA solutions for optical mold applications. The study shows a dramatic roughness reduction to nanometer-range for both (1 0 0) and (1 1 0) sidewall planes when etched under very low etch rate conditions controlled by the etchant concentration and the etching temperature. The results show that the surface roughness measured by confocal laser microscope was 10.75 nm for (1 0 0) plane and 7.83 nm for (1 1 0) plane under the etch rate of 25.61 nm/min and 24.61 nm/min, respectively.