Effects of point defects on the electrical properties of doped diamond

The effect that point defects have on the electrical properties of p- and n -type diamond are reported. Protons are used to introduced well-known amoun ts of point defects into a single-crystal B-doped diamond layer and P-doped CVD homoepitaxial diamond films through which they are shot at ever-increa sing doses. For both p- and n-type diamonds, an abrupt increase in resistiv ity is found to set in at a particular density of defects introduced by the H irradiation, however, this onset occurs for n-type sample at a dose 10(3 ) higher then for the p-type diamond. This observation can be explained if the introduced defects act as compensating donors. For the B-doped diamond a monotonic reduction in carrier concentration and in carrier mobility, con current with an increase in compensation ratio, are observed as function of damaging ion dose. High-temperature annealing subsequent to implantation o f hydrogen through, or into, the doped layers restores the electrical prope rties of the p-type layer and leaves the H profiles unaltered, indicating t hat ion-implanted hydrogen in diamond is immobile, even in the presence of accepters, and no H-B electrically active complexes are formed. (C) 2000 El sevier Science S.A. All rights reserved.