Characterization of phosphorus doped CVD diamond films by cathodoluminescence spectroscopy and topography

摘要

A phosphorus doped homoepitaxial diamond film made by a CVD method was investigated by cathodoluminescence spectroscopy and topography. An exciton peak bound to phosphorus at 239 nm was observed from {001} as well as {111}, but the wavelength and width of the peak varied depending on location of the sample. This may be due to the difference of crystal perfection. It was found in the spectra that the slope with an array of weak peaks has a maximum of approximately 270 nm. This broad band may be an indicator of incororation of phosphorus, although all the phosphorus doped diamonds do not exhbit the band. No other peak expected to be related to phosphorus was found, but several peaks commonly observed from CVD diamond were seen instead. These were also dependent on growth surface. Peaks at 415, 482, 500, 514 and 532 nm were strong on {111} surfaces of the non-epitaxial crystallinites, whereas teh 575-nm peak and another system of the 532-nm peaks were stronger in {001} epitaxial layers, as reported earlier.