We describe hot-filament chem. vapor deposition of polyisobenzofuran (PIBF) films and characterize their chem. structure and surface morphol. The precursor monomer, 1,2,3,4-tetrahydro-1,4-epoxy-naphthalene, is pyrolyzed by flowing it over an array of hot filaments held at three different temps. (680, 738, and 800 °C). The produced intermediate, iso benzofuran , is deposited onto a silicon substrate as thin films of PIBF. Fourier transform IR spectroscopy and XPS revealed that the films prepd. at 800 °C possess a chem. structure and a compn. different from those prepd. at lower filament temps. (680 and 738 °C). Increasing filament temp. also leads to the formation of defect domains in the polymer films. By at. force microscopy, we observe a decrease in surface roughness and in the av. size of polymer grains in PIBF domains as the filament temp. is increased. Defect domains exhibit a rougher surface as well as larger size polymer grains than those in PIBF domains. Spectroscopic and microscopic results suggest that growth of the polymer in the defect domains proceeds by a mechanism different from that in the PIBF domains. [on SciFinder(R)]