The nature of the damage which was introduced by ion-impact and annealing was studied experimentally and theoretically. The experimental methods included measurements of changes in conductivity, density and Raman spectra in natural type-IIa crystals which contained various amounts of implantation-induced damage and had been subjected to various annealing treatments (up to 1300K, 1200s). The simulations which were performed were based upon molecular dynamics computations, using the Tersoff potential. A deeply buried highly damaged region was created within the sample by imparting a high momentum to lattice atoms which were aimed towards the same point of the crystal. The damage which was created was analyzed statistically and yielded information on the formation of 3-fold coordinated atoms in the damage-region. A transformation which the damaged region underwent as a result of annealing (up to 4000K, 50ps) was investigated. Both experiment and theory showed that diamond which contained a low density of point defects could anneal back to diamond whereas, at damage levels above a certain level, it tended to graphitize. The stable defect in damaged material was, according to both experiment and theory, the <100> split interstitial. The point defects acted as donor centers.

Ion Implantation-Induced Defects in Diamond and their Annealing: Experiment and Simulation. R.Kalish, A.Reznik, S.Prawer, D.Saada, J.Adler: Physica Status Solidi A, 1999, 174[1], 83-99