Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-15T01:41:47.656Z Has data issue: false hasContentIssue false

Laser-Reflectance Interferometry Measurements of Diamond-Film Growth

Published online by Cambridge University Press:  29 November 2013

Get access

Extract

The remarkable properties of diamond, including its hardness, chemical inertness, high thermal conductivity, low coefficient of friction, optical transparency, and semiconducting properties, have led to considerable research in the area of diamond thin-film deposition. Diamond films have been characterized ex situ by a large number of diagnostic techniques including Raman spectroscopy, x-ray diffraction, SEM, and TEM. In situ diagnostics, which can provide information in real time as the film is growing, are less common.

Laser-reflectance interferometry (LRI) has been used to monitor the growth of diamond films in situ. The technique involves measuring the intensity of a laser beam reflected from the substrate surface on which the film is growing. The reflected beam is the sum of beams reflected by the gas-diamond interface and the diamond-silicon interface. Oscillations in the reflectivity are observed as the film grows because of interference between the reflected beams. Each oscillation indicates an increase in film thickness of λ/2n, where λ is the laser wavelength and n is the index of refraction of the film. If the index of refraction of the film is known, the thickness and growth rate can be determined in situ. For LRI measurements with 632.8-nm-wavelength HeNe lasers, the index of refraction of diamond films has been found to be within 10% of the bulk diamond value of 2.4. Each oscillation therefore indicates an increase in film thickness of 0.13 μm.

The reflectivity measured by LRI is also affected by scattering because of surface roughness.

Type
In Situ, Real-Time Characterization of Thin-Film Growth Processes
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Yarbrough, W.A. and Messier, R., Science 247 (1990) p. 689.CrossRefGoogle Scholar
2.Zhu, W., Stoner, B.R., Williams, B.E., and Glass, J.T., Proc. IEEE 79 (1991) p. 621.CrossRefGoogle Scholar
3.Stoner, B.R., Williams, B.E., Wolter, S.D., Nishimura, K., and Glass, J.T., J. Mater. Res. 7 (1992) p. 257.CrossRefGoogle Scholar
4.Mathis, B.S. and Bonnot, A.M., Diamond Related Mater. 2 (1993) p. 718.CrossRefGoogle Scholar
5.Bonnot, A.M., Mathis, B.S., and Mpulin, S., Appl. Phys. Lett. 63 (1993) p. 1,754.CrossRefGoogle Scholar
6.Bonnot, A.M., Lopez-Rios, T., Mathis, B.S, and Leroy, J., Diamond Related Mater. 1 (1992) p. 161.CrossRefGoogle Scholar
7.Wild, C., Müller-Sebert, W., Eckermann, T., and Koidl, P., in Proc. Appl. Diamond Conf. 1991, edited by Tzeng, Y., Yoshikawa, M., Murakawa, M., and Feldman, A. (Elsevier, Amsterdam, 1991) p. 197.Google Scholar
8.Wild, C., Koidl, P., Müller-Sebert, W., Walcher, H., Kohl, R., Herres, N., Locher, R., Samlenski, R., and Brenn, R., Diamond Related Mater. 2 (1993) p. 158.CrossRefGoogle Scholar
9.Carniglia, C.K., Opt. Eng. 18 (1979) p. 104.CrossRefGoogle Scholar
10.Gruen, D.M., Liu, S., Krauss, A.R., and Pan, X., J. Appl. Phys. 75 (1994) p. 1,758.CrossRefGoogle Scholar
11.Knight, D.S. and White, W.B., J. Mater. Res. 4 (1989) p. 385.CrossRefGoogle Scholar
12.Zhu, W., Inspector, A., Badzian, A.R., McKenna, T. and Messier, R., J. Appl. Phys. 68 (1990) p. 1,489.CrossRefGoogle Scholar
13.Gruen, D.M., Zuiker, C.D., Krauss, A.R., and Pan, X., J. Vac. Sci. Technol. in press.Google Scholar
14.Bachmann, P.K., Bausen, H.D., Lade, H., Leers, D., Wiechert, D.U., Herres, N., Kohl, R., and Koidl, P., Diamond Related Mater. 3 (1994) p. 1,308.CrossRefGoogle Scholar