RADIATION-ENHANCED TRANSPORT OF HYDROGEN IN SIO2

2.2 MeV He-4(+) and 7 MeV N-15(2+) ion beams have been used to investi gate, by in situ measurements, the hydrogen desorption processes in Si O2 thin films deposited by plasma enhanced chemical vapor deposition ( PECVD). An effective cross-section of 3 x 10(-16) cm(2) for He and 17 x 10(-16) cm(2) for N has been measured for the ion-thin-film interact ion phenomena, The structure crystalline silicon/thermally grown SiO2/ PECVD film has also been investigated for the hydrogen radiation-enhan ced diffusion in thermally grown SiO2. The data are consistent with a diffusion process with a diffusion coefficient of (5.0 +/- 0.5) x 10(- 26) cm(2)/ion from a constant source at a concentration C-0 = (2.5 +/- 0.2) x 10(21) at/cm(3). (C) 1997 Elsevier Science B.V.