157nm photodissociation of polyamides

Research for new photoresists for 157nm photolithography requites the inves tigation of the basic photochemical studies at this wavelength The parent m olecule disintegrates to small fragments, which are flying apart with super sonic speed Therefore the photodissociation process, could impose serious p roblems on the optics of the focusing system by contaminating it. In order to investigate the basic photochemical mechanisms of the photodissociation dynamics of various polymeric materials at 157nm, we have used nylon 6.6 as test material. This is mainly because the nylon 6.6 monomer has the potent ial to dissociate into small photofragments in which most of the photoresis ts used for 193 and 157nm photolithography am likely to be dissociated. Hen ce we report on the mass spectroscopy of nylon 6.6 at 157nm, using an F-2 p ulsed discharge molecular laser. At this wavelength there is complete photo chemical bond braking in the energy range from 1 to 8mJ/cm(2) per pulse. Th e monomer dissociates into fragments with the predominant mass at 28amu The refore the amide group is mainly involved in the photodissociation process of nylon 6.6 at 157mm.