Photoemission study of direct photomicromachining in poly(vinylidene fluoride)

Direct pattern transfer onto poly(vinylidene fluoride) was achieved by usin g x-ray photons from a synchrotron radiation source. Quadrupole mass spectr ometry and ultraviolet photoemission spectroscopy, combined with ab initio molecular orbital calculations, were employed to investigate the mechanism of direct photomicromachining. The mass spectrometry identified H-2, F, and HF as the etched products, with no carbon containing species being detecte d. The changes in photoemission spectra due to photodegradation were analyz ed by comparison with ab initio molecular orbital calculations. This analys is indicated that a high degree of conjugation is generated in the degraded polymer due to the loss of fluorine atoms. It is concluded that the mechan ism of direct photomicromachining is ascribable to the shrinking of the irr adiated polymer region due to defluorination and the generation of conjugat ion. (C) 2000 American Institute of Physics. [S0021-8979(00)03208-4].