LATTICE LOCATION AND ANNEALING STUDIES OF HEAVY-ION IMPLANTED DIAMOND

The lattice location of ion implanted In into type Ila diamond and the annealing of implantation damage was studied with the emission channe ling technique. Radioactive In-111 was implanted into IIa diamonds wit h [110] surface orientation at 300 K, at energies of 120 and 350 keV a nd at doses between 5 x 10(12) and 5 x 10(13) cm-2 . Axial channeling effects of the emitted conversion electrons were measured after anneal ing to different temperatures up to 1473 K. For implantation doses bel ow 10(13) cm-2 two stages for annealing of implantation defects are ob served, one between 300 and 600 K and the other above 1000 K The appea rance of strong channeling effects in all major axial directions after annealing at 1473 K indicates a significant substitutional fraction o f In atoms. From a comparison with calculated emission channeling prof iles a substitutional fraction of up to 45% was determined. The experi mental data are also consistent with a close-to-substitutional fractio n of about 50-60% assuming small mean displacements of the In atoms of about 0.1 angstrom. A significant fraction of In on tetrahedral inter stitial sites can be ruled out.