Characterization of diamond films

D.S. Knight, W.B. White, Characterization of diamond films by Raman spectroscopy, Journal of Materials Research, 4 (2011) 385-393. 

G. H. Ma, Y. H. Lee, and J. T. Glass, Electron microscopic characterization of diamond films grown on Si by bias-controlled chemical vapor deposition, J. Mater. 

X Zhu, BR Stoner, BE Williams, JT Glass. Growth and characterization of diamond films on nondiamond substrates for electronic applications. Proc IEEE 79 621, 1991. 

Fig. 3.7 Typical micro-Raman (a), XRD (b) and SEM (c) characterization results of diamond film deposited on titanium substrate...

The physical properties of diamond films largely correspond to those of the macroscopic material. The only significant differences to bulk diamond arise from surface defects and from a possible doping. The spectroscopic properties are employed to characterize the diamond films obtained, to evaluate their quality and, where applicable, to identify defects and impurities. In the following, the main attention will be directed just to those features differing from the bulk properties of diamond. Further aspects are also discussed in Section 5.4 on the physical properties of nanodiamond that shares some characteristics with the so-called ultrananocrystalline diamond in particular. 

Kim et al.f studied the effect of gas pressure on the nucleation behavior of diamond on a Si(lOO) substrate in HFCVD. The pressure was varied from 2 to 50 torr, while a filament temperature of2200°C, a substrate temperature of 850°C, a total flow rate of 20 seem and a CH4 concentration of 0.8 vol.% were used. The characterization of diamond deposits using micro-Raman spectroscopy, SEM and OM revealed that the maximum nucleation density of diamond parades on the unscratched Si substrate occurred at a pressure of 5 torr. The pressure dependence of the nucleation density was explained by the competition effect between P-SiC formation, which increases the diamond nucleation density, and atomic-hydrogen etching, which decreases the nmnber of nucleation sites. On the basis of this finding, a new fabrication approach for high-quality diamond films without... 

E. N. Loubnin, In-situ laser interferometry characterization of nucleation and growth of diamond films. Diamond Films and Technol, 3(1) 1-15 (1993)... 

Scanning electron miCToscopy (SEM) has been a very useful technique in the characterization of diamond thin films. The microstructure of diamond films changes... 

X-ray diffraction (XRD) is sensitive to the presence of crystalline carbons such as diamond or graphite instead of amorphous carbon. Hence, it is frequently used to characterize CVD diamond films. NCD films exhibit a similar pattern compared to conventionally synthesized MCD films [38]. Three peaks, related to (111), (220) and (311) crystalline diamond peaks are observed. Compared to the MCD films, the diffraction peaks of NCD are sigifificantly broadened due to the very small diamond grain sizes. 

Davis, R.R (1994) Deposition and characterization of diamond, silicon carbide and gallium nitride thin films. /. Cryst. Growth, 137(1-2), 161-169. 

C. D. Zuiker, A. R. Krauss, D. M. Gruen et al., Characterization of diamond thin films by core-level photoabsorption and UV excitation raman spectroscopy in Applications of Synchrotron Radiation Techniques to Material Sciences III (Eds. L. J. Terminello, S. M. Mini, H. Ade etal.). Proceedings of the Materials Research Society, San Francisco, April 8-12,1996, p. 211, Vol. 437. 

Sahoo, S., Pradhan, S.S., Bhavanasi, V., Pradhan, S.K., 2010. Structural and mechanical characterization of diamond like carbon films grown by microwave plasma CVD. Surf. Coat. Technol. 204, 2817-2821. 

Waldvogel SR, Mentizi S, Kirste A (2011) Use of diamond films in organic electrosynthesis. In Brilias E, Marttnez-Huitle CA (eds) Synthetic diamond films -preparation, electrochemistry, characterization and applications. Wiiey-VCH, Hoboken, New Jersey, pp 483-510... 

The application of Raman spectroscopy to the studies of diamondlike carbon (DLC) films has been reviewed in this volume (Chap. 22 and 24) and elsewhere [147]. Recent hardware developments involve the application of UV excitation to the study of DLC films [148-151]. Recently, a patent was granted to SI Diamond Technology [152] covering the application of UV-excited Raman spectroscopy for the characterization of carbon films used in the construction of a field-emission cathode. UV-excited Raman spectroscopy, however, is likely to be limited to the research environment due to the cost and complexity of the instrumentation. 

A sharp peak was observed at 1332 cm, which is characteristic of diamond and reflects a high degree of crystallinity, as shown in Fig. 2.4. In addition, a broad peak centered at approximately 1200 cm was observed, which is usually attributed to either amorphous diamond or extremely small diamond crystallites [20]. The absence of a peak at -1500 cm i indicates that the polycrystalline films are free from sp carbon impurities. This type of peak was observed only in poor quality films. The details of Raman characterization of diamond thin films are discussed in detail in Chapter 5. 

Raman Microspectroscopy. Raman spectra of small soflds or small regions of soflds can be obtained at a spatial resolution of about 1 p.m usiag a Raman microprobe. A widespread appHcation is ia the characterization of materials. For example, the Raman microprobe is used to measure lattice strain ia semiconductors (30) and polymers (31,32), and to identify graphitic regions ia diamond films (33). The microprobe has long been employed to identify fluid iaclusions ia minerals (34), and is iacreasiagly popular for identification of iaclusions ia glass (qv) (35). 

According to the characterizations by TEM and XRD, the sample prepared from a CH4/H2 plasma was composed of nanocrystalline diamond and disordered microcrystalline graphite. Then nondiamond carbon was effectively removed with an increase in [CO]. It is therefore concluded that the VDOS of the nanocrystalline diamond and DEC films extracted from the HREELS data is in qualitative agreement with the characterizations of TEM and XRD. Although the HREELS probes only the region near the surface, the agreement suggests that the surface dynamics do not differ dramatically from those of the bulk. 

A.H. Deutchman and R.J. Partyka (Beam Alloy Corporation observe, "Characterization and classification of thin diamond films depend both on advanced surface-analysis techniques capable of analyzing elemental composition and microstructure (morphology and crystallinity), and on measurement of macroscopic mechanical, electrical, optical and thermal properties. Because diamond films are very thin (I to 2 micrometers or less) and grain and crystal sizes are very small, scanning electron microscopy... 

Below we give an overview of electrochemical behavior of synthetic diamond films and discuss some applications of electrochemical methods to their characterization. We attempt to predict prospects for this new area of electrochemistry. When touching fundamentals of the electrochemistry of semiconductors, we refer to the monograph [6] for details. 

One may expect that future work on the electrochemistry of diamond should take two paths, namely, an extensive investigation (search for new processes and applications of the carbon allotropes in the electrochemical science and engineering) and intensive one (elucidation of the reaction mechanisms, revealing the effects of crystal structure and semiconductor properties on the electrochemical behavior of diamond and related materials). It is expected that better insight into these effects will result in the development of standard procedures for thin-film-electrodes growth, their characterization, and surface preparation. 

The overview by Pleskov covers the literature on electrochemical behavior of synthetic diamond films, as well as the use of electrochemical methods in their characterization. The rapid advancement of the field of diamond electrochemistry was triggered by progress in the technology of deposition of polycrystalline diamond thin films on diamond and other substrates. Advances around the world have by now led to formation of a self-consistent, but as yet incomplete, view of electrochemical behavior of diamond. While discrepancies and scatter between data from different research groups still exist, the rapid advance in film quality and in reliable methods of evaluation point to a promising future. 

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