Influence of the boron-doped layer on the secondary electron emission and morphology of diamond film

In this paper, diamond films with different thickness of surface boron-doped were prepared by microwave plasma chemical vapor deposition (MPCVD). The effects of the thickness of boron doping layer on surface morphology, crystal quality and secondary electron emission performance of the diamond films were investigated. The results show that the grain size of the film with boron-doping layer is larger than that of the film without boron-doping layer, but the grain size of the film changes little along with the increase of the thickness of the boron-doping layer. Raman spectra show that the crystal quality of the film is the best situation when the thickness of boron doping layer is 0.5 μm and a higher secondary electron emission coefficient of 7.17 at the incident electron energy 200 $\text{eV}$ is obtained in this case.