CHARACTERIZATION OF AMORPHOUS-CARBON THIN-FILMS

The objective of this study is to develop improved procedures for char acterizing amorphous carbon films. Raman spectroscopy is used to chara cterize amorphous carbon thin films grown by pulsed laser deposition a t temperatures between 293 and 873 K. The amount of bond-angle disorde r is shown to decrease with increasing substrate temperature. However, a shift of the Raman D peak to higher wave numbers is not observed to coincide with the presumed decrease in sp(3) bonding as the depositio n temperature increases. The graphitic domain size is shown to initial ly decrease, pass through a minimum, and then increase as temperature increases. Mass densities, measured independently by x-ray specular re flectometry, are seen to decrease from a maximum of 2.4 g/cm(-3) as de position temperature increases. The trend in the observed density meas urements correlates well with the Raman spectroscopy data. The importa nce of x-ray specular reflectometry as part of a strategy to completel y characterize amorphous carbon films is discussed in terms of these d ata. (C) 1996 American Vacuum Society.