Synthesis of Diamond Films by Laser-Induced Chemical Vapor Deposition

Abstract

An experimental study of diamond formation by laser-induced chemical vapor deposition (CVD) technique using a gaseous mixture of H₂ and CCl₄ is reported. The laser used in this work is an ArF excimer laser which emits 80 - 200 mJ pulses with 20 ns duration. We have succeeded in obtaining thin films of diamond by the activation of hydrogen to enhance the removal of graphite and the production of CH radicals. Films obtained without the activation were composed of amorphous carbon and graphite. Hydrogen was activated by a microwave discharge tube or a hot tungsten filament. Films were characterized by Raman scattering and reflection electron diffraction. The diagnostic study using a visible optical emission spectroscope shows that the emission intensity ratio of CH to C₂ radicals increases in the system with the activation.