Si ion implantation study of InAs/GaSb type II superlattice materials

Class II superlattice infrared detectors generally detect infrared radiation through mesa junction, while transverse PN junction is realized through ion implantation. On the one hand, the material epitaxy process is simple, and at the same time, the advantages of superlattice material that the transverse diffusion length is far higher than the longitudinal can be used to improve the transport of photogenerated current carriers, and it is easy to make high-density planar arrays. In this paper, the effects of Si ion implantation with different energies and annealing on the properties of InAs/ GaSb type II superlattice materials were studied by using a variety of material characterization techniques. Through Si ion implantation, the epitaxial material changes from P type to N type, and the vertical tensile strain is generated in the superlattice material. The lattice constant becomes larger, and the mismatch increases with the increase of implantation energy. The mismatch before implantation is-0. 012%. When the implantation energy reaches 200 keV, the mismatch reaches 0. 072%, and the superlattice partially relaxes, with the relaxation degree of 14%. After annealing at 300 degrees C for 60 s, the superlattice returns to the fully strained state, and the lattice constant becomes smaller, This tensile strain is caused by the diffusion of Ga-In caused by annealing and lattice shrinkage caused by Si substitution.