Correlation of the structure and electrical properties of ion-implanted and laser-annealed silicon

Abstract

Both transmission electron microscopy and four-point probe measurements have been used to compare the structure and electrical properties of As+- and P+-ion-implanted and Q-switched laser-annealed Si. Use of a uniform laser beam permitted accurate correlations to be made. It was found that the thickness of the initial amorphous surface layer controlled the radiation energy densities required for annealing onset and completion. Annealing onset variations were probably due to changes in the coupling of the radiation with the ion-damaged region. The variation in depth distribution of residual defects with changes in annealing conditions has been determined and shown often to produce a two-stage annealing characteristic. The effect of such defects on annealed-layer electrical properties has been determined. The presence of very-small-scale undulations on annealed surfaces is thought to be due to the propagation of shock waves through the annealed region.