The present invention provides a novel monomer, which provides a new functionality by including a novel monomer formed by a bond between a pentagonal cyclic olefin molecule and a photosensitive molecule, may control mechanical and thermal properties, and is formed by a bond between Chemical Formula 1 and any one of Chemical Formulae 2 to 4 in order to perform chemical recycling through reversible chemical changes according to the external stimulus.

The present invention provides a novel monomer, which provides a new functionality by including a novel monomer formed by a bond between a pentagonal cyclic olefin molecule and a photosensitive molecule, may control mechanical and thermal properties, and is formed by a bond between Chemical Formula 1 and any one of Chemical Formulae 2 to 4 in order to perform chemical recycling through reversible chemical changes according to the external stimulus.

A compound and a polymer for a photolithographic medium composition, and the photolithographic medium composition is provided. The polymer has a structural unit represented by general formula (1) below. The compound and polymer are configured for use in an etching-resistant medium layer.

##STR00001##

A compound and a polymer for a photolithographic medium composition, and the photolithographic medium composition is provided. The polymer has a structural unit represented by general formula (1) below. The compound and polymer are configured for use in an etching-resistant medium layer.

##STR00001##