RBS and optical studies of ion-implanted amorphous silicon carbide layers

Optical properties of ion-implanted a-Si1-xCx:H for x = 0.08 and 0.15 carbon contents have been studied. We investigated the influence of medium (2.5-5 x 10(15) cm(-2), 50 and 150keV Fe+ ions) as well as high fluences (10(16)- 10(17) cm(-2), 45 keV Cu+ ions) implanted into 100 and 200 nm layers of silicon carbide deposited on the c-Si substrates. The optical constants n and k were evaluated by the ellipsometric method. A considerable increase of the extinction coefficient k was noticed for the low-energy implantation into 100 nm layers for both ion fluences. The transmission spectra of a-Si1-xCx:H deposited on the glass substrate indicated the red shift of the absorption edge depending on the implantation fluence. The above-mentioned increase of the k coefficient can be attributed to the growing density of vacancies and the increase of implant atom concentration in the sub-surface layers. This effect of optical contrast formation is already very strong for the samples with the iron atom concentration of 0.7%, as obtained by the RBS analysis. Together with the sub-micron ion-beam techniques, it can be utilized for high-density data recording. (C) 2003 Elsevier Science Ltd. All rights reserved.