High resolution photoresist based on imide containing polymers

Abstract

Abstract Photoresist compositions suitable for deep UV and excimer laser lithography are disclosed that are mixtures of a photoacid and a polymer having imide residues to which acid labile groups are attached. The imide group ##STR1## can be blocked with certain groups, X, to form compounds containing the structure ##STR2## which have solubility properties different from the unblocked imide. These groups, X, can be cleaved by acid under the proper conditions to regenerate the unblocked imide. Where the imide group is incorporated in a polymer, the polymer with blocked imide groups can be made to function as a resist when compounded with a substance capable of forming an acid upon exposure to radiation. Preferred polymers are those in which at least 80% of the imide groups are blocked. When less than 50% of the imide groups are blocked, performance in a photoresist becomes unacceptable. When the special T-shaped profile needed for the metal lift-off method is required, at least about 50% of the imide groups should be blocked but not more than about 75%.

Inventors

• 👤 Christopher E. Osuch
• 👤 Michael J. McFarland

Bibliographic Details