Helium implantation effects in hard hydrogenated carbon layers
Hard amorphous films of a-C:D were deposited by a rf glow discharge in CD(4). The implantation of 40 keV 3He(+) ions in these films was studied as a function of the helium fluence at temperatures between 100 K and room temperature. The trapped amounts of helium and the deuterium losses in the layer were measured in situ using nuclear reaction analysis with 0.5 MeV D(+) and 1 MeV 3He(+) beams, respectively, and subsequent ex-situ elastic-recoil detection analysis. A transient helium retention appeared in the carbonised layers, occurring only at temperatures below 200 K. Above a critical fluence which depended on temperature and ion flux, outdiffusion of He was observed, which was ascribed to the formation of diffusion channels by radiation damage. The deuterium depletion induced by helium bombardment below 200 K sets on in correlation with the helium outdiffusion, but is otherwise independent of the helium trapping.
Bibliographic Reference: Article: Journal of Applied Physics, Vol. 68 (1990) No. 5, pp. 2068-2072
Record Number: 199011819 / Last updated on: 1994-12-02
Original language: en
Available languages: en