Effects of thermal treatment on porous amorphous fluoropolymer film with alow dielectric constant

Amorphous fluoropolymer (AF thin films have been prepared from Teflon AF 16 00 solution by spin-coating. Scanning electron micrograph (SEM) observation s reveal that the film has planar and compact surface without any pinhole, and there are many pores in the matrix. By capacitance-voltage (C-V) and cu rrent-voltage (I-V) measurements, the dielectric constant of the AF film is equal to 1.57 at 1 MHz. and breakdown strength is 2.07 MV cm(-1). The Four ier transform infrared spectroscopy (FTIR) spectra and X-ray diffraction (X RD) patterns of the films show that the films have excellent thermal stabil ity below 400 degreesC, and thermal treatment does not change amorphous nat ure of the films. X-ray photoelectron spectroscopy (XPS) spectra reveal dec omposition of CF3 groups due to annealing at 400 degreesC. leading to a rem arkable increase in CF2 groups. Possible decomposition mechanisms of AF fil m are also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.