Thin layers of Ti (230nm) and C (202nm) were deposited onto SiO2/Si substrates by means of electron beam evaporation under high vacuum. These films were annealed (525-625C, 240s to 2h) so as to grow thin films of TiC. The use of Ar+ sputter depth-profiling, and Auger electron spectroscopy, revealed the depth composition of the annealed films. A comparison of the Auger electron spectra of C in the graphite and carbide chemical states revealed significant differences in both the shape and energy of the differentiated peaks. A positive restricted linear least-squares method was used to separate the graphite and carbide contributions from the C profile. The TiC layer thickness for each specimen was obtained. With a known TiC thickness and annealing time, the diffusion coefficient as a function of temperature could be calculated. The results could be described by:

D (m2/s) = 4.1 x 10-8 exp[-207(kJ/mol)/RT]

Extracting Interdiffusion Parameters of TiC from AES Depth Profiles. H.C.Swart, A.J.Jonker, C.H.Claassens, R.Chen, L.A.Venter, P.Ramoshebe, E.Wurth, J.J.Terblans, W.D.Roos: Applied Surface Science, 2003, 205[1-4], 231-9