Highly reliable growth process of carbon nanowalls using radical injection plasma-enhanced chemical vapor deposition

Two-dimensional carbon nanostructures, carbon nanowalls (CNWs), were fabricated on a Si substrate using radical injection plasma-enhanced chemical vapor deposition, employing fluorocarbon (C2F6) and hydrogen (H-2) mixtures. The influence of the surface conditions of the chamber wall on CNW growth was investigated in order to determine the optimum conditions for CNW growth with high stability and reproducibility. In order to monitor the surface conditions of the chamber wall, optical emission spectroscopy in the plasma was measured, and the correlation between CNW growth and the surface conditions in the chamber wall was investigated. The growth rate and morphology of grown CNWs were determined to be influenced by the surface conditions of the chamber wall. Furthermore, O-2 plasma chamber cleaning followed by predeposition for passivation was found to be effective for maintaining steady conditions to attain CNWs with high reproducibility. (c) 2008 American Vacuum Society.