Highly compensated surface layers were found on n-type semiconducting crystals after implantation with ions of various type and mass. The thicknesses of these layers were in the micron range, and exceeded the projected range of the implanted ions. A study was made of the dependence of this compensation phenomenon upon the ion dose and energy, and upon the dopant level of the crystals. The results were explained in terms of a new damage model which included the possibility that native defects that were produced in the collision cascade could diffuse deeply into the crystal by taking migration energy from the excited electronic ensemble. In this way, a defect penetration depth which was of the order of the electronic diffusion length could be attained.

H.Kerkow, V.X.Quang, B.Selle: Journal of Crystal Growth, 1992, 117, 677-81