B-11(+)-ion implantation (30 or 100 keV, 1X10(15) cm(-2)) in boron-doped chemical-vapor-deposited (CVD) diamond has been investigated using Raman spectroscopy and cathodoluminescence (CL). Hydrogen plasma treatment was employed in order to restore the implantation-induced defects and to etch away the heavily damaged surface layers of as-implanted samples. For the samples doped with a low concentration of boron atoms (B/C (in feedgas) = 20-200 ppm), a greater fraction of the residual defects is significantly reduced after the plasma treatment, i.e. the residual non-diamond components and point defects, such as interstitial carbons and vacancies, in the diamond lattice are substantially reduced.