Poly(1,4-phenyleneazine N,N-dioxide): A Recyclable Material for a Solventless Laser-Imageable Resist Process

Abstract

Upon heating under vacuum, poly(1,4-phenyleneazine-N,N-dioxide) depolymerizes to give 1,4-dinitrosobenzene which can be condensed onto a suitable substrate. The nature of the condensate is dependent on the substrate temperature. At temperatures below −110 °C the condensate can be monomeric, at about −50 °C it is a mixture of dimer and oligomers, and at −20 °C it is polymeric. Thick and thin films of the polymer can be rapidly prepared by volatilization of 1,4-dinitrosobenzene from the bulk polymer onto a substrate and allowing the collected condensate to warm to room temperature. The resultant films appear to be stable indefinitely at room temperature and atmospheric pressure yet can be selectively removed from the substrate using a focused visible laser beam. After a suitable image-transfer process, the polymer is removed by heating to 100 °C. The laser imaging, deposition, and final removal of polymer are all nondestructive, thermal processes. Thus if a suitable vacuum chamber equipped with a cooling trap is used for this process, the polymer is 100% recyclable. © 1994, American Chemical Society. All rights reserved.