RAMAN CHARACTERIZATION OF GAAS DOPED WITH SN BY LASER-ASSISTED DIFFUSION

GaAs was heavily doped with Sn by a laser assisted diffusion procedure . The energy density of the laser was varied between 0.3 and 0.7 J cm- 2. MicroRaman spectroscopy was used to evaluate in depth the dopant ac tivation and the damage produced by the procedure. It is shown that be low the top heavily doped layer there is a layer characterized by sign ificant lattice damage. The existence of this layer is due to the impu rity diffusion mechanism and depends on the laser energy density; ther e is a laser energy density window, 0.35-0.5 J cm-2, for which this la yer is significantly reduced.