Nanomolecular resists with adamantane core for 193-nm lithography

To satisfy the upcoming demand of next generation lithography, new chemically amplified resist materials should be developed that can perform at the limit where the image feature size is on the order of molecular dimensions. Amorphous low-molecular-weight materials have several advantages over conventional polymeric systems. First, the limit of resolution can be enhanced since the building block of the image feature shrinks to the small molecule. Second, nanomolecular materials do not have chain entanglement due to the short chain length. Third, resist molecules that are free of intermolecular chain entanglement may decrease line edge roughness at very small feature sizes. Fourth, they can be coated on the silicon substrate by spin coating method because of their amorphous properties. Herein we studied several nanomolecular resists for 193-nm lithography. Adamantane was used as a core and two cholate derivatives were attached to adamantane.