RETENTION AND EROSION BEHAVIOR OF OXYGEN-IMPLANTED IN DIFFERENT SI C-MATERIALS/

Different Si/C-material like plasma deposited thin a-Si/C:H films, bul k Si doped graphites (SiC30) and pure silicon have been irradiated wit h an oxygen ion beam of the isotope O-18 at energies between 1 and 5 k eV and at target temperatures up to 1700 K. The release of oxygen and oxygen containing molecules during irradiation and during subsequent t hermal desorption has been analyzed by means of quadrupole mass spectr ometry 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 o f CO and CO2 depending on the silicon content of the sample. Furthermo re, 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 additiona l release of SiO during irradiation at elevated temperatures as well a s during subsequent thermal desorption.