Retention and erosion behavior of oxygen implanted in different Si/C-materials

Different Si/C-materials like plasma deposited thin a-Si/C:H films, bulk Si doped graphites (SiC30) and pure silicon have been irradiated with an oxygen ion beam of the isotope 18O at energies between 1 and 5 keV and at target temperatures up to 1700 K. The release of oxygen and oxygen containing molecules during irradiation and during subsequent thermal desorption has been analyzed by means of quadrupole mass spectrometry in both the residual gas and direct 'line-of-sight' detection. All investigated materials show an enhanced oxygen retention compared to pure graphite and a markedly reduced chemical erosion in the form of CO and CO2 depending on the silicon content of the sample. Furthermore, the oxygen impact onto such substrates gives rise to a build up of a silicon oxide layer at the near surface. This leads to an additional release of SiO during irradiation at elevated temperatures as well as during subsequent thermal desorption. (orig.)