Direct patterning of photosensitive low-dielectric-constant films using electron-beam lithography

A direct patterning technique of interlayer dielectric films was developed for multilevel interconnections. A photosensitive methylsilazane film with a dielectric constant of 2.7 was synthesized. A methylsilazane precursor consists of a photoacid generator, a sensitizer, and a base polymer. The photosensitive methylsilazane film could be patterned by use of electron-beam lithography or ultraviolet lithography. It was demonstrated that the smallest feature size of 50 nm for damascene lines and via holes could be directly patterned in these films by electron-beam lithography. (C) 2001 American Institute of Physics.