Effect of residual stress on the Raman-spectrum analysis of tetrahedral amorphous carbon films

Tetrahedral amorphous carbon (ta-C) films deposited by the filtered vacuum arc process have large compressive residual growth stresses that depend on the atomic-bond structure. We observed that the G peak of the Raman spectru m shifts to higher frequency by 4.1 +/-0.5 cm(-1)/GPa due to the residual c ompressive stress. This value agrees well with the calculated Raman-peak sh ift of the graphite plane due to applied stress. By considering the effect of residual stress on the G-peak position, we also observe a similar depend ence between the G-peak position and the atomic-bond structure in both ta-C and hydrogenated amorphous carbon (a-C:H) films; namely, that a higher sp( 2) bond content shifts the G-peak position to higher frequency. (C) 2001 Am erican Institute of Physics.