High-resolution DLTS of vacancy–donor pairs in P-, As- and Sb-doped silicon

Abstract

We report results from an experiment designed to characterize, by high-resolution (Laplace) DLTS, the electronic properties of electron radiation induced E-centers in Si associated with P, Sb and As. Four sets of samples that contained (i) only P, (ii) P and Sb, (iii) P and As, and (iv) P, Sb and As were used. In the sample containing only P, the activation energy of electron emission from the single acceptor level of V–P in silicon was found to be (0.458±0.005) eV. For the sample with P and Sb, the Laplace peaks of the V–Sb and V–P were clearly separated and the ratio of their emission rates was always >4. The energy levels extracted were (0.401±0.01) and (0.442±0.01) eV for the V–Sb and V–P, respectively. The levels calculated for V–P in these two samples can be considered to be, within the experimental error, the same. In the sample with As and P, the ratio of the emission rate of V–As to V–P was 1.8 and the result was that, although the V–As and V–P peaks could clearly be split, there is some inaccuracy in their calculated energy level positions of (0.435±0.005) and (0.434±0.01) eV, respectively. In the sample containing all three dopants, the peaks of V–P, V–Sb and V–As could be separated but the DLTS “signatures” of these E-centers differed significantly from those where only one or two E-centers were present.