Arsenic-ion implantation-induced defects in HgCdTe films studied with Hall-effect measurements and mobility spectrum analysis

Nano-scale structural studies of defects in arsenic-implanted n and p-type HgCdTe films

“…These carriers are known to originate in the atoms of interstitial mercury captured by implantation-induced structural defects, such as dislocation loops visualized in our nanoscale structural studies (Figs. 1, 2, 3, 4, 5 see also Izhnin et al 2018Izhnin et al , 2019. In sample #1, these electrons provided partial conductivity 11.7 (Ohm cm) -1 , as the primary MSEs (Fig.…”

“…As the final goal of the performed implantation was the formation of 'p + -n'-junctions suitable for the fabrication of photodiodes, we also studied the electrical properties of the implanted material. For that purpose, we measured the magnetic field B dependences of the Hall coefficient and the conductivity in the B = 0.01-1.5 T range at 77 K. The obtained data were analyzed with the use of the discrete mobility spectrum analysis (DMSA, Izhnin et al 2019); this technique allows for determining the number of carrier species and their parameters: concentration, mobility and partial conductivity. In particular, the analysis of sample #1 (n-type) showed that its conductivity before the implantation was dominated by high-mobility electrons (majority carriers) with average (reduced to the total thickness of the film) concentration 3.9•10 15 cm -3 ; mobility, 87,500 cm 2 / (V s); and average partial conductivity 54.6 (Ohm cm) -1 with directly measured total conductivity equaling 56.6 (Ohm cm) −1 .…”

“…The high-mobility electrons in the n-layers of the n + -n-p structures are known to originate in the residual (or intentionally introduced, as in our case with indium doping) donors that determine the conductivity after the atoms of Hg I had diffused into the crystal and annihilated with mercury vacancies that defined the p-type conductivity before the implantation (Izhnin et al 2018). The intermediate-mobility electrons (or at least a part of them) originated in the donor complexes that Hg I atoms form with quasi-point defects induced by the implantation (Izhnin et al 2019).…”

“…In MCT-based 'p + -n'-junctions, however the high electrical conductivity of the n-region hinders obtaining this information due to a very large difference between electron and hole mobility. As a result, the effect of arsenic implantation on the electrical properties of MCT is often studied after implantation into p-type material (Izhnin et al 2019). This approach presumes that the formation of implantation-induced structural defects proceeds similarly in the 'base' MCT layers with p and n-type conductivity.…”