Aromatic polyurea was prepared by vapor deposition polymerization of 4,4-diaminodiphenyl methane and 4,4-diphenylmethane diisocyanate. Mass spectrometric analysis revealed depolymerization of the polyurea. The polyurea evaporated completely at 300 degrees C or lower in vacuum. UV exposed polyurea did not evaporate even at temperatures higher than 300 degrees C. To exploit the thermal resistance of the exposed and unexposed polyurea, patterned films were prepared with 5 mu m resolution. It was found that the polyurea could be used as a negative resist material, and that an all-dry lithographic process was possible.