To develop new functional devices, it is necessary to form finer patterns. However, when the pattern width is reduced, the aspect ratio (height/width) of the pattern increases and the pattern easily collapses.
To solve this problem, we have developed supercritical reist drying (SRD) techniques. These SEM images indicate ZEP resist patterns after development and drying. SRD enables patterns to form without any pattern collapse,whereas conventional drying causes 20-nm wide patterns to collapse. This means that SRD is an effective method of improving the resolution.

Conventional N2 Drying

Supercritical Drying (SRD)

Ref.
H. Namatsu, K. Yamazaki, and K. Kurihara, J. Vac. Sci. Technol. B18(2), 780 (2000).

Supercritical Resist Drying (SRD)