Oriented Graphitic Carbon Film Grown by Mass-Selected Ion Beam Deposition at Elevated Temperatures

Abstract

Mass-selected ion-beam deposition using 120 eV C⁺ ions has been used to grow a carbon film on a Si substrate held at 200° C. The structure of the film has been characterized by transmission electron microscopy and electron energy loss spectroscopy. The film is graphitic and highly oriented with the c-axis lying parallel to the substrate. Moreover, the film is under significant biaxial stress such that the graphitic layer spacing is reduced by 4% from that of ambient pressure graphite. This oriented structure evolves due to the mobility of the carbon atoms at 200 °C. The material is sufficiently crystalline on the nanometer scale so as to produce Bragg diffraction discs in a convergent beam electron diffraction pattern using a 2.5 nm probe.