Laser Method for Synthesis and Processing of Continuous Diamond Films on Nondiamond Substrates

Abstract

A laser method based upon carbon ion implantation and pulsed laser melting of copper has been used to produce continuous diamond thin film. Carbon ions were implanted with ion energies in the range of 60 to 120 keV, and doses of 1.0 x 10¹⁸ to 2.0 x 10¹⁸ ions cm^–2. The ion-implanted specimens were treated with nanosecond excimer laser pulses with the following parameters: energy density, 3.0 to 5.0 J cm^–2; wavelength, 0.308 µm; pulse width, 45 nanoseconds. The specimens were characterized with scanning electron microscopy (SEM), x-ray diffraction, Rutherford backscattering/ion channeling, Auger, and Raman spectroscopy. The macroscopic Raman spectra contained a strong peak at 1332 cm^–1 with full width at half maximum of 5 cm^–1, which is very close to the quality of the spectra obtained from single-crystal diamond. The selected area electron diffraction patterns and imaging confirmed the films to be defect-free single crystal over large areas of up to several square micrometers with no grain boundaries. Low voltage SEM imaging of surface features indicated the film to be continuous with presence of growth steps.