Efficacy of low etch rate in achieving nanometer-scale smoothness of Si (100) and (110) plane surfaces using KOH and KOH/IPA solutions for optical mold applications

• Published in: Sensors and actuators. A. Physical. 2014-03, Vol.209, p.124-132
• Main Authors: An, Shinmo, Lee, Seung Gol, Park, Se-Guen, Lee, El-Hang, O, Beom-Hoan
• Format: Article
• Language: English
• Subjects: Actuators; Confocal; Effectiveness; Etching; Imprinting; Molds; Planes; Silicon; Silicon wet etching; Smoothness; Surface roughness
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2014.01.018

•Surface roughness reduction of wet chemical etched Si (100) and (110) planes using KOH and KOH/IPA solutions by controlling the etchant concentration and temperature.•Surface roughness of both planes are related with the etch rate.•With low etch rate conditions, the etched surface roughness is minimized.•Silicon mold having vertical and 45°-inclined sidewalls have been fabricated.•Polymer replica has been fabricated. This paper reports on the efficacy of low etch rate in achieving nanometer-scale smoothness of Si (100) and (110) 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 (100) and (110) 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 10.75nm for (100) plane and 7.83nm for (110) plane under the etch rate of 25.61nm/min and 24.61nm/min, respectively.