SURFACE-REACTION AND STABILITY OF PARYLENE-N AND PARYLENE-F THIN-FILMS AT ELEVATED-TEMPERATURES

The morphology and chemical structure of Parylene F and Parylene N films annealed in air, N-2, and vacuum were examined. The decomposition temperatures of Parylene N in air, N-2, and vacuum were determined to be 175, 350, and 425 degrees C, respectively. The decomposition temperatures of Parylene F in air and N-2 were determined to be 400 and 500 degrees C, respectively. For both materials, the decomposition process with and without the presence of O is different. In the case of Parylene N, O diffuses into the materials and reacts with the C in the polymer. In the case of Parylene F, no reaction products with O are observed on the surface. Annealing at the decomposition temperature resulted in the decomposition of -CF2- functional groups to -CF- functional groups in the Parylene F. Thicker films, >1 mu m, of either material cracked during annealing while films <0.5 mu m, remained smooth and transparent. Pinholes were also observed in the Parylene F film deposited using the Gorham method after annealing.