Dry process ultraviolet patterning of paracyclophane to polyparaxylylene

Upon warming to about 60 °C, [2,2]paracyclophane (PCP) and monochloro[2,2] paracyclophane (cPCP) can be deposited by sublimation onto target surfaces at −78 °C in an evacuated chamber. Light with wavelengths less than 250 nm can then be used to photopolymerize the deposited PCP or cPCP to polyparaxylylenes while still cold or after warming them back to room temperature. When the photolyzed material is heated to roughly 100 °C, the unexposed paracyclophanes evaporate, leaving polyparaxylylene behind. If the paracyclophane is exposed to the UV light through a patterned mask, submicron features of polyparaxylylene can be produced; however, the maximum film thickness which can be made in a single exposure is about 0.1 μm.