Dependency of p-n junction depth on ion species implanted in HgCdTe

We assessed p-n junction depth and stress in HgCdTe implanted with various ion species. After post-implantation annealing, junction depth was measured using a differential Hall measurement. The stress induced by implantation was determined by measuring wafer curvature or using Raman spectroscopy. Samples with B or Mg implantation had p-n junctions that were three to five times deeper than samples with Ca, Cd, or Hg implantation. The implantation of elements with a small ionic radius, such as B or Mg, leads to compressive stress in implantation layers. In contrast, the implantation of Ca, Cd, or Hg, which are ions with a radius similar to that of Hg cations, leads to a comparatively high tensile stress in the layers. The results indicate that the stress is caused by a change in volume when the implanted ions substitute the Hg sublattice and by an increase in volume caused by the generation of vacancies and interstistials. These results suggest that implantation-induced stress is an important factor influencing the depth of p-n junctions.