Effect of deposition temperature on the properties of amorphous carbon thin film deposited using natural precursor by thermal CVD

Abstract

Amorphous carbon (a-C) thin films were deposited on quartz substrate at different deposition temperature by thermal chemical vapor deposition (CVD) method using natural precursor ‘camphor oil’. All samples were grown in fixed conditions except the deposition temperature was varied from 400°C to 800°C. The a-C thin films were characterized by using UV-Vis spectroscopy, I-V measurement, Raman spectroscopy and Atomic Force Microscopy (AFM). The UV-Vis analysis was used to obtain the optical band gap. The optical bang gap was decreased from 1.0eV to 0.1eV with the increasing the deposition temperature. The electrical conductivity of a-C thin films increased as the deposition temperature increased. Raman results show that high deposition temperature induced more graphitization in the thin films. The sp2 and sp3-bonded carbon amount in a-C structure could effect the optical band gap of the a-C thin films. These a-C thin films were found to be dependent on the deposition temperature and amount of sp2 and sp3 bonded carbon.