The lattice sites of ion-implanted radioactive 33P in natural type-IIa crystals were studied by using emission channelling techniques. The 30keV 33P ions were implanted at room temperature to a dose of 1011/cm2. The implanted samples were then annealed in vacuum at up to 1200C. From channelling data on -particles, a fraction of 70% of substitutional P was deduced. A vanishingly small fraction was situated on tetrahedral interstitial sites, plus a random fraction of 30%. The displacements of the P atoms from the ideal substitutional sites were less than 0.02nm. This demonstrated that P was a substitutional impurity in diamond, and that the efficient substitutional P doping of diamond could be obtained by using a conventional implantation and annealing procedure if low implantation doses were used.

H.Hofsäss, M.Dalmer, M.Restle, C.Ronning: Journal of Applied Physics, 1997, 81[6], 2566-9