DIFFUSION OF BORON, LITHIUM, OXYGEN, HYDROGEN, AND NITROGEN IN TYPE IIA NATURAL DIAMOND

Diffusion of boron, lithium, nitrogen, oxygen, and hydrogen into type IIa natural diamond was studied. The diffusion was performed in two steps. First, diffusion of Li and oxygen was performed in nitrogen atmosphere at 860 °C for one hour. The sample was then placed in a hot filament chemical vapor deposition (CVD) growth reactor and diffusion was performed for two hours in hydrogen atmosphere from a boron solid source placed on the surface of the sample. The condition of diffusion were those used routinely during CVD growth. After diffusion, the concentration of Li was of the order of 2×10 16 cm-3 at the depth of 0.5 micrometer, and oxygen, nitrogen, and boron were found to be in the range (1-4)×1020 cm-3 at the same depth. The diffusion of hydrogen under conditions specific to CVD growth has also been studied for the first time and was found to be quite strong. © 1995 American Institute of Physics.