Characterization of chemical vapour deposited diamond films: correlation between hydrogen incorporation and film morphology and quality

• Published in: Journal of physics. Condensed matter Vol. 17; no. 10; pp. 1687 - 1695
• Main Authors: Tang, C J, Neves, A J, Carmo, M C
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 16.03.2005; Institute of Physics
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; CVD; Scanning electron microscopy; Raman spectra; Microwave radiation; Hydrogen additions; Color; Diamonds; Fourier transform spectra; PECVD; Infrared spectra; Microstructure; Faceting
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/17/10/022

In order to tailor diamond synthesized through chemical vapour deposition (CVD) for different applications, many diamond films of different colours and variable quality were deposited by a 5 kW microwave plasma CVD reactor under different growth conditions. The morphology, quality and hydrogen incorporation of these films were characterized using scanning electron microscopy (SEM), Raman and Fourier-transform infrared (FTIR) spectroscopy, respectively. From this study, a general trend between hydrogen incorporation and film colour, morphology and quality was found. That is, as the films sorted by colour gradually become darker, ranging from white through grey to black, high magnification SEM images illustrate that the smoothness of the well defined crystalline facet gradually decreases and second nucleation starts to appear on it, indicating gradual degradation of the crystalline quality. Correspondingly, Raman spectra evidence that the diamond Raman peak at 1332 cm-1 becomes broader and the non-diamond carbon band around 1500 cm-1 starts to appear and becomes stronger, confirming increase of the non-diamond component and decrease of the phase purity of the film, while FTIR spectra show that the CH stretching band and the two CVD diamond specific peaks around 2830 cm-1 rise rapidly, and this indicates that the total amount of hydrogen incorporated into the film increases significantly.