Growth studies of laser-induced CVD diamond films
Journal de Physique IV : Proceedings
The growth of laser-induced chemical vapour deposition diamond thin films are studied. The X-ray diffraction (XRD) and electron diffract ion analysis showed the structure of these film layers change from an amorphous to polycrystaline is obtained on scratched silicon substrate and at different growth conditions, The process of growth and structure of these films have been discussed. I -INTRODUCTION Diamond has superior properties for example great hardnessl high thermal conductivity, chemical
... ctivity, chemical inertness, high stiffness, high carrier mobilities etc. Diamond coatings and f ilms have been prepared from the vapor phase at low pressure. These preparation techniques have been developed include chemical vapor deposit ion (CVD) [I], ion beam techniques [2l, plasma induced deposition [31, microwave plasma deposition[ll and variations or hybrids of these, Laser induced CVD seems to proceed through a mechanism quite different from that of other methods. In the paper,we report the growth condition and structure of laser induced-CVD of diamond films. It is shown that the polycrys tall ine diamond films with good crystallinity are obtained on roughened < I l l > silicon substrate. The experiment indicates these films are more uniform and the growth temperature is lower than using conventional methods 161. Fig. 1 .The reaction is carried out by use of methane diluted with H2 ( CH, concentration 1%) as a source gas ( H, + CH, f at low pressure. The smooth substrate surface of (111) silicon is scratched and roughened to facilitate nucleation before growth beginning.The substrate is kept at a temperature of 60-700%. In experiment the irradiation of focused two laser beams ( h = 266nm) are separately against and parallel from the substrate ( Fig. 1) , the power density on the substrate is 60mJ/cma pulse. The diagram of experimental set-up for laser-induced CVD diamond film is shown in Article published online by EDP Sciences and available at http://dx.