Extended and point defects in diamond studied with the aid of various forms of microscopy

It is shown that star disclinations can be a significant source of stress i n chemical vapor deposited (CVD) diamond. This purely geometrical origin co ntrasts with other sources of stress that have been proposed previously. Th e effectiveness is demonstrated of the use of electron irradiation using a transmission electron microscope (TEM) to displace atoms from their equilib rium sites to investigate intrinsic defects and impurities in CVD diamond. After irradiation, the samples are studied by low temperature photoluminesc ence microscopy using UV or blue laser illumination. Results are given that are interpreted as arising from isolated <100> split self-interstitials an d positively charged single vacancies. Negatively charged single vacancies can also be revealed by this technique. Nitrogen and boron impurities may a lso be studied similarly. In addition, a newly developed liquid gallium sou rce scanned ion beam mass spectrometry (SIMS) instrument has been used to m ap out the B distribution in B doped CVD diamond specimens. The results are supported by micro-Raman spectroscopy.