E-catalog        

Библиогр.: 38 назв.

Heteroepitaxial n-Hg0.78Cd0.22Te films with near-surface graded-gap layers
were grown by molecular beam epitaxy and subjected to two-stage thermal
annealing in saturated mercury vapor atmosphere. The first stage of
annealing was carried out for 2 h at a temperature of 360C. The second stage
was carried out at a temperature of 220C for 24 h. Similar annealing was
carried out after As+ ion implantation to activate the introduced impurity and
anneal radiation defects. Based on as-grown and annealed films, metal–insulator–
semiconductor (MIS) structures were formed by depositing an Al2O3
dielectric by plasma atomic layer deposition. The admittance of fabricated MIS
structures was studied in a wide range of frequencies and temperatures. It
was found that after thermal annealing, the properties of the n-HgCdTe
surface layer are noticeably changed, which is manifested as a decrease in the
density of slow states in the transition layer between the dielectric and the
semiconductor, and an increase in the generation of minority charge carriers
in the n-HgCdTe near-surface layer. These changes in the properties of n-
HgCdTe after thermal annealing are associated with the modification of the
defect system of the near-surface layer of the semiconductor and the transition
layer between dielectric and semiconductor. No significant changes were detected
in the bulk properties of the epitaxial film after thermal annealing. A
decrease in the density of states near the interface between HgCdTe and Al2O3
during thermal annealing makes it possible to facilitate the electrical characterization
of MIS structures by suppressing hysteresis phenomena.