Deep ultra-violet Raman imaging of CVD boron-doped and non-doped diamond films

Deep UV (244 nm) Raman images were recorded on CVD diamond films. The different images recorded on boron-doped polycrystalline film reveal large differences on the boron level within individual crystallites. Nevertheless, inspite of an enhanced intensity of the diamond line, the UV Raman spectra are less informative than the visible Raman spectra due to the weak response of the boron-related peaks. The images recorded on an un-doped homoepitaxial diamond film reveal a defective domain exhibiting in the same areas the sp³ CH_x stretching vibration component and the first and second-order optical phonons of the graphite-like phonon bands of sp² carbons embedded in a compressive zone of polycrystalline diamond.