FTIR spectroscopy and FTIR microscopy of vacuum-evaporated polyimide thin films

Polyimide (PI) thin films can be formed by vapor co-deposition of the precu rsor molecules pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA) if the resulting polyamic acid film is heated above 150 degrees C, The effe cts of dose stoichiometry and curing temperature on the imidization rate an d crystallization of PI films were investigated using Fourier transform inf rared (FTIR) spectroscopy and microscopy. The apparent spectral resolution was enhanced using the Fourier self-deconvolution (FSD) method and the prof iles were then fully deconvoluted by a curve fitting procedure. The FSD met hod followed by curve fitting was used to evaluate quantitatively the areas under the isoimide peaks. The microscopic study showed no evidence for PMD A phase separation and crystallization. PI films deposited under optimum co nditions showed a maximum imidization and crystal structure superior to tha t of films fabricated by other techniques, (C) 1999 Elsevier Science B.V. A ll rights reserved.