Solid-Phase Epitaxial Regrowth of Phosphorus Implanted Amorphized Germanium

Abstract

This paper reports on the Solid Phase Epitaxial Regrowth (SPER) of phosphorus implanted pre-amorphized p-type germanium at 350 oC using Rapid Thermal Annealing and focuses more specifically on the P concentration dependence of the regrowth velocity. This is studied by a combination of Rutherford Backscattering in the channeling mode (RBS-C) and Secondary Ion Mass Spectrometry (SIMS). As will be shown, different regimes can be distinguished whereby for chemical concentrations up to 4-5x1020 cm-3 an enhanced recrystallization occurs compared with undoped amorphized Ge. Above this metastable solid solubility limit, the regrowth is retarded, due to the redistribution and snow plow of the excess P across the amorphous/crystalline interface. It will also be demonstrated that during SPER at 350 oC, limited P-diffusion occurs even at the highest implantation dose studied.