The mechanism of generation of donor centres in p-InSb by laser radiation

The laser-induced donor centers in p-InSb have been studied by magneto-concentration effect MCE.. The distribution of In vacancies in a nonuniform temperature field in InSb has been performed in term of the model of redistribution of the In vacancies under laser action. Comparison of the theoretical and experimental data has shown that the depth of the p–n junction increases with temperature and that the relatively large value of the p–n junction localization depth at intensities of laser radiation exceeding 3.5 MW cmy2 is connected with presence of the liquid phase in the laser modification process. These results are confirmed by atomic force microscopy AFM.of the surface morphology. Experiments were performed on InSb samples in the temperature range 180–290 K. Temperature gradient was provided by YAG:Nd laser illumination ls0.53 mm, tps15 ns.. Two kinds of laser donor centers LDC. were found: one is nonstable, annealed at room temperature with relaxation constant ;5 s, and the other is stable, annealed at 670 K. The threshold of LDC formation is 1.5 MW cmy2. The activation energy of the stable donor centre is ;1.1 eV. q1999 Elsevier Science B.V. All rights reserved.