Boron Doping Nano Diamond Film Preparation And Its Performance Study

Boron doped nanocrystalline diamond film (BDND), as a material with wellconductity, smooth surface and low frictional coefficient, has great prospect ofapplying in high-tech fields. In this paper, BDND were prepared in the intermissionmode and the continue mode by DC hot cathode PCVD system. The main work wedone showed as follow:1. In the intermission mode experiment, the quality of the diamond films,such asgrain size, crystal orientation and the surface smoothness, was enhanced through lessboron doping in the films. However, as the boron content was further increased, thegrain size and the grain boundaries were increased. In the study of the growth time,we found that longer growth time resulted in larger diamond grains.The BDND withhigh quality were prepared when the growth time was20minute, CH4flow rate was8sccm and B(OCH3)3flow rate was10sccm, the grain size was10～20nm.2. The boron doped diamond films were prepared in rich-Ar atmosphere. Theresults showed that, with the increase of Ar/H2flow ratio, the grain size of the filmsdecreased and the conductivity of the films became better. The BDND film wasprepared when Ar/H2flow ratio was190/10. In the study of the influence of gaspressure, both higher and lower gas pressure were useful to second nucleation. Theboron doped diamond film, prepared at lower gas pressure, has less larger grains.3. We prepared boron and nitrogen co-doped diamond films and obtained thetechnic condition of preparation of boron doped nanocrystalline diamond film. Theresults showed that, the grain sizes of decreased to nanometer scale with the surfaceof the diamond film turned to be smooth and compact when N2flow rate was6sccm.The resuls of Raman spectra and XRD pattern showed that, the concentration ofamorphous carbon increased with the addition of nitrogen, and the quality of thediamond films drop. It was also conductive to the growth of diamond (100) faces.