3-D determination of the location of non-diamond bound carbon, impurities, and stress components within a single crystal in a CVD diamond film using polarized Micro-Raman spectroscopy

Abstract

Summary form only given. It is known that different growth sectors within a single crystal on a CVD diamond film contain different concentrations of defects, which can be found in the form of inclusions of non-diamond bound carbon, impurities, as well as forms of intrinsic defects in the crystal lattice. So far, these regions have been identified using unpolarized Micro-Raman spectroscopy and photo-luminescence. In the present study we show the exact location of non-diamond bound carbon, impurities such as dopants, and the corresponding stress components in a single crystal within a CVD diamond film in all three dimensions using polarized Micro-Raman spectroscopy. The diamond film was heteroepitaxially grown on a silicon substrate in a microwave plasma reactor. The use of high-vacuum gas handling systems combined with optical emission spectroscopy allows exact determination of the various gas phase concentrations down to a few ppm. The use of polarized Micro-Raman spectroscopy allows exact positioning of the measured volume due to the use of high resolution microscope objectives and translation stages, as well as accurate determination of the hydrostatic and axial stress components. Non-diamond bound carbon and other impurities are detected as well. Determination of the stress components is done by measuring the shift and split of the three phonons, which are triply degenerate in unstressed diamond.