5 December 1995; accepted for publication 25 March 1996 | J. Schwan, S. Ulrich, V. Batori, and H. Ehrhardt S. R. P. Silva
This paper discusses the Raman spectroscopy of amorphous (hydrogenated) carbon films deposited at room temperature, focusing on the interpretation of Raman features in the 1000–1700 cm⁻¹ region. The authors examine the linewidths, positions of the "G" graphite peak and "D" disordered peak, and their intensity ratios, using results from magnetron sputtered and magnetic field enhanced plasma deposited films. They show that even small clusters of condensed benzene rings (cluster size below 20 Å) can explain the observed Raman scattering. The paper highlights the importance of correctly interpreting Raman results and discusses the utility of Raman scattering in estimating cluster sizes in amorphous (hydrogenated) carbon films. Additionally, it is found that carbon films prepared by magnetron sputtering show two additional Raman features at 1180 and 1490 cm⁻¹, which correlate with the sp³ content in the films. The paper also explores the relationship between the 1180 cm⁻¹ peak and the sp³ content, and discusses the line broadening effects in amorphous carbon, including the influence of cluster size, distribution, stress, and chemical bonding. The authors conclude that the complexity of the Raman spectra of amorphous carbon requires careful interpretation, and that the G and D lines do not necessarily require large cluster sizes.This paper discusses the Raman spectroscopy of amorphous (hydrogenated) carbon films deposited at room temperature, focusing on the interpretation of Raman features in the 1000–1700 cm⁻¹ region. The authors examine the linewidths, positions of the "G" graphite peak and "D" disordered peak, and their intensity ratios, using results from magnetron sputtered and magnetic field enhanced plasma deposited films. They show that even small clusters of condensed benzene rings (cluster size below 20 Å) can explain the observed Raman scattering. The paper highlights the importance of correctly interpreting Raman results and discusses the utility of Raman scattering in estimating cluster sizes in amorphous (hydrogenated) carbon films. Additionally, it is found that carbon films prepared by magnetron sputtering show two additional Raman features at 1180 and 1490 cm⁻¹, which correlate with the sp³ content in the films. The paper also explores the relationship between the 1180 cm⁻¹ peak and the sp³ content, and discusses the line broadening effects in amorphous carbon, including the influence of cluster size, distribution, stress, and chemical bonding. The authors conclude that the complexity of the Raman spectra of amorphous carbon requires careful interpretation, and that the G and D lines do not necessarily require large cluster sizes.