Growth kinetic study of amorphous carbon thin film deposited by Ion Beam Sputtering deposition (IBSD) method using Avrami's model

The growth kinetic of amorphous carbon (a-C) thin films was investigated in the relation to the surface morphology and structural transformations. The a-C thin films were deposited by ion beam sputtering technique on the glass substrate. According to Avrami's model, the growth at the thickness above 56 nm (after 900 s deposition) is two-dimensional and the proposed equation for investigating about the growth process of amorphous carbon thin film in the present study is as follows: V=1-exp⁡(-2×〖10〗^(-7) t^2 ). Transformations of the thickness is similar to proposed Avrami's model follow a characteristic s-shaped, or sigmoidal, profile during deposition time from 300s to 4500s, where the transformation rates are low at the beginning and the end of the transformation but rapid in between. Surface roughness and structural transformation depend on the film thickness. Raman spectra showed the maximum displacement in G peak position created in the film thickness equal 360 nm with the reduction of the growth rate. The ID/IG ratio, the size of graphite crystallites with sp2 bonds (La) and the roughness of this layer is equal to 1.2, 1.48 nm and 20.39±4.8 nm, respectively.