INVESTIGATION OF HYDROGENATED AMORPHOUS-CARBON (A-C-H) FILMS PRODUCEDBY ARF (193 NM) LASER-ABLATION OF POLY(METHYL METHACRYLATE)

Hydrogenated amorphous carbon (a-C:H) films have been deposited on Si, quartz and NaCl by pulsed 193-nm laser ablation of poly (methyl-metha crylate) under vacuum. Wavelength dispersed studies of the visible emi ssion accompanying the ablation plume show it to be dominated by the B almer series of atomic hydrogen. The extent of the emission plume sugg ests that electronically excited H atoms are created in flight, probab ly via collisions between much larger particles produced in the primar y ablation process. Such a picture accords with the results of microco mbustion analysis and infra-red transmission spectroscopy, both of whi ch indicate that, compared to the original target material, the deposi ted a-C:H film is deficient in H (and O). (C) 1998 Elsevier Science S. A.