Aqueous-based photoresist drying using supercritical carbon dioxide to prevent pattern collapse

Capillary forces naturally present during normal drying of photoresist materials were eliminated by developing a supercritical drying process. Supercritical carbon dioxide, organic solvents and surfactants were used to prevent the collapse of high-aspect-ratio structures fabricated from aqueous-based photoresist. The replacement of the aqueous rinse by n-hexane mediated by a compatible surfactant was introduced.