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

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