Raman scattering of tetrahedrally-bonded amorphous carbon deposited at oblique angles
Contributors: Minseo Park, S.M. Camphausen, A.F. Myers, P.T. Barletta, V. Sakhrani, L. Bergman, Robert J. Nemanich, and Jerome J. Cuomo
ABSTRACT
Amorphous carbon (txa-C1−x) films were prepared by filtered cathodic arc deposition (FCAD). The films were deposited on p-type Si (111). The angle of beam incidence was varied from 0° to 75° with respect to the substrate normal. Micro-Raman spectroscopy, electron energy loss spectroscopy (EELS), and transmission electron microscopy (TEM) were carried out for sample analysis. It was found that the position of the G peak shifts to a higher wave number region as the angle of incidence increases. This means that the sp2/sp3 ratio increases with increasing angle. This conclusion is supported by EELS. The film deposited at an angle of 75° exhibits a columnar structure with alternating high and low carbon density regions.