물중탕을 이용한 대면적 SiNx EUV 펠리클 제작

Abstract

EUV (Extreme Ultraviolet) pellicle which protects a mask from contamination became a critical issue for the application of EUV lithography to high-volume manufacturing. However, researches of EUV pellicle are still delayed due to no typical manufacturing methods for large-scale EUV pellicle. In this study, EUV pellicle membrane manufacturing method using not only KOH (potassium hydroxide) wet etching process but also a water bath was suggested for uniform etchant temperature distribution. KOH wet etching rates according to KOH solution concentration and solution temperature were confirmed and proper etch condition was selected. After KOH wet etching condition was set, 5 cm x 5cm SiNx (silicon nitride) pellicle membrane with 80 % EUV transmittance was successfully manufactured. Transmittance results showed the feasibility of wet etching method with water bath as a large-scale EUV pellicle manufacturing method.