DEFECTS IN ARSENIC IMPLANTED [p.sup.+]-n- AND [n.sup.+]-p-STRUCTURES BASED ON MBE GROWN CdHgTe FILMS

Complex studies of the defect structure of arsenic-implanted (with the energy of 190 keV) [Cd.sub.x][Hg.sub.1-x]Te (x = 0.22) films grown by molecular-beam epitaxy are carried out. The investigations were performed using secondary-ion mass spectroscopy, transmission electron microscopy, optical reflection in the visible region of the spectrum, and electrical measurements. Radiation donor defects were studied in [n.sup.+]-p- and [n.sup.+]-n-structures obtained by implantation and formed on the basis of p-type and n-type materials, respectively, without activation annealing. It is shown that in the layer of the distribution of implanted ions, a layer of large extended defects with low density is formed in the near-surface region followed by a layer of smaller extended defects with larger density. A different character of accumulation of electrically active donor defects in the films with and without a protective graded-gap surface layer has been revealed. It is demonstrated that [p.sup.+]-n-structures are formed on the basis of n-type material upon activation of arsenic in the process of postimplantation thermal annealing with 100% activation of impurity and complete annihilation of radiation donor defects. Keywords: CdHgTe, ion implantation of As, radiation defects, activation annealing.