Supercritical drying for high aspect-ratio HSQ nano-structures
The benefits of supercritical resist drying (SRD) technique using carbon dioxide (CO2) are investigated with respect to the resolution of dense patterns and the aspect ratio (AR) of nano-structures in rather thick HSQ layers. For double lines separated by a distance of 50nm the maximum achievable AR is trebled using SRD processes compared to conventional nitrogen blow. The mechanical stability of resist structures is significantly improved by using SRD.
hsq supercritical resist drying srd aspect ratio electron beam lithography