Infrared spectroscopy of C-D vibrational modes on diamond (100) surfaces

A high resolution analysis of C-D vibrational modes on single crystal diamo nd using Fourier transform infrared spectroscopy is reported. This method h as the advantage over high resolution electron energy loss spectroscopy of a far superior resolution (< 1 cm(-1) versus similar to 10 cm(-1)). The inh erently low surface sensitivity of the former method was overcome by measur ing the IR absorption in the attenuated total reflection mode employing a G e prism. The use of deuterium instead of hydrogen avoids the interference f rom airborne hydrocarbon contamination. We present data on the diamond (100 ) surface that was deuterated in a microwave plasma and subjected to a seri es of isothermal annealing treatments at 700 degrees C. The C-D stretching mode at 2181 cm(-1) and the bending mode at 1054 cm(-1) could be followed d own to a tenth of a monolayer coverage. From the intensity ratio of these b ands measured in s- and p-polarization the essentially perpendicular dispos ition of the C-D bonds has been inferred. (C) 1999 Elsevier Science B.V. Al l rights reserved.