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Hydrogen-incorporated nanocrystalline diamond thin films have been deposited in microwave plasma enhanced chemical vapour deposition (CVD) system with various hydrogen concentrations in the Ar/CH4 gas mixture. The bonding environment of carbon atoms was detected by Raman spectroscopy and the hydrogen concentration was determined by elastic recoil detection analysis. Incorporation of H2 species into Ar-rich plasma was observed to markedly alter the microstructure of diamond films. Raman spectroscopy results showed that part of the hydrogen is bonded to carbon atoms. Raman spectra also indicated the increase of non-diamond phase with the decrease in crystallite size. The study addresses the effects of hydrogen trapping in the samples when hydrogen concentration in the plasma increased during diamond growth and its relation with defective grain boundary region.

Article history:Received 28 November 2008Received in revised form 5 March 2009Accepted 28 April 2009Available online 3 May 2009PACS:68.55.Ln82.80.Yc81.07.BcKeywords:CVD diamond filmsHydrogenGrain size dependenceERDAXPSRS In this investigation, diamond thin films with grain size ranging from 50 nm to 1 µm deposited using hotfilament chemical vapor deposition (HFCVD) have been analyzed by elastic recoil detection analysis (ERDA)for determining hydrogen concentration. Hydrogen concentration in diamond thin films increases withdecreasing grain size. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) results showed thatpart of this hydrogen is bonded to carbon forming C–H bonding. Raman spectra also indicated the increase ofnon diamond phase with the decrease in crystallite size. Incorporation of hydrogen in the samples andincrease of hydrogencontent in nanocrystalline sample are discussed. Large separation between filament andsubstrate used for the synthesis of nanocrystalline film helped to understand the large incorporation ofhydrogen in nanocrystalline diamond films during growth. The study addresses the hydrogen trapping indifferent samples and higher hydrogen concentration in nanocrystallites by considering the synthesisconditions, growth mechanisms for different grain sized diamond films and from the quality of CVD diamondfilms.© 2009 Elsevier B.V. All rights reserved.

BF2+ implantation and low temperature furnace annealing are used to form Ti silicide and shallow junctions for samples with multilayers of Si/Ti/Si. The formation of Ti silicides and the shallow junctions is investigated by Rutherford backscattering, the 19F(p,αγ) nuclear reaction, Cu Kα X-ray diffraction and spreading resistance measurement. The mechanism of interaction of Ti and Si, and the influences of impurities F, O and a thin amorphous Si surface layer are discussed.