UV in-situ degradation of PMPSi analysed by spectroscopic ellipsometry, XPS and TDS

presentation

English

PMPSi (poly(methyl-phenylsilane)) films were deposited by the spin-coating method on single crystal silicon substrates from toluene solution. Their thickness was about 200 nm. We have studied the stability of these films, which is crucial for their technological applications [1,2], by in-situ spectroscopic ellipsometry (SE) and X-ray Photoelectron Spectroscopy (XPS). This has been proved as a proper combination of monitoring methods as XPS gives direct insight into compositional and structural changes of the polymer (5-10 nm below the surface) and the SE technique is very sensitive to the changes in PMPSi films. We have used rotating analyzer ellipsometry in the energy interval 3.4 - 4.8 eV to cover the onset of absorption starting with the lowest excitonic band involving electronic stays localized on Si. The ellipsometer is mounted on an UHV chamber, the angles of incident light can be adjusted to 45 or 67.5 . Our recent study [3] indicates that the Si-Si bonds in the polymer main chain (Si-backbone) were primarily broken by the UV-light treatment. We present here the results of optical studies of changes of PMPSi layers exposed to the UV light under UHV (10- 7 Pa) and atmospheric conditions, and treated at different temperatures. TDS spectra (Thermal Desorption Spectroscopy) will be used to determine the film fragments leaving the film during its degradation.

spectroscopic ellipsometry; XPS; TDS; PMPSi

BONAVENTUROVÁ - ZRZAVECKÁ, O.; BRANDEJSOVÁ, E.; ČECHAL, J.; POTOČEK, M.; NEBOJSA, A.; NAVRÁTIL, K.; ŠIKOLA, T.; HUMLÍČEK, J.

25. 9. 2005

Vienna

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