SUBSTITUTIONAL PHOSPHORUS DOPING OF DIAMOND BY ION-IMPLANTATION

We have studied the lattice sites of ion-implanted radioactive P-33 in natural IIa diamond using the emission channeling technique. P-33 ion s were implanted at room temperature with 30 keV and a rather low dose of 10(11) cm(-2) and the implanted samples were annealed in vacuum to 1200 degrees C. From the channeling effects of the emitted beta(-) pa rticles measured for all principal axial directions we obtain a fracti on of 70+/-10% of substitutional P, a vanishing fraction on tetrahedra l interstitial sites and a 30% random fraction. Possible displacements of the P atoms from ideal substitutional sites must be below 0.2 Angs trom. This demonstrates that P is a substitutional impurity in diamond and efficient substitutional P doping of diamond can be accomplished by a conventional implantation and annealing procedure if low implanta tion doses are chosen. (C) 1997 American Institute of Physics.