SUMMARYIn the present investigation, three separate projects are described. First, P+ implanted Si is laser and furnace annealed, and the resulting structures as observed by TEM are compared. Second, similar studies are made of Zn+ implanted GaAs, the laser annealing being performed either with or without a surface encapsulating layer. Third, As+ implanted Si is laser annealed, and the uniformity of the annealing process as determined by SEM EBIC studies is assessed. The results have shown that different damage structures can be produced by laser annealing compared to furnace annealing, and by different laser energy densities. For the laser annealed specimens, the TEM observations provided evidence for the formation of a molten surface layer. The results demonstrated for GaAs that encapsulation was still required for laser annealing, and for Si that laser annealing can give a varying p‐n junction depth within individual slices. The latter is explained by a molten surface layer extending to different depths during the annealing process, this being attributed to spatial variations in laser intensity across the area illuminate