Effect of the arsenic cracking zone temperature on the efficiency of arsenic incorporation in CdHgTe films in molecular-beam epitaxy

CdxHg1-xTe films with x ∼ 0.22 and thickness of ∼10 μm have been grown by molecular-beam epitaxy on gallium arsenide substrates and doped in situ with arsenic. Activation annealing of doped films provided p-type conduction with a hole density of up to 1017 cm-3. The influence exerted by the arsenic cracking zone temperature on the efficiency of arsenic incorporation into the CdHgTe film was studied. A model describing the dependence of the arsenic concentration in the films on the arsenic cracking zone temperature was suggested. A comparison of the model and the experimental data demonstrated that the incorporation efficiency of diatomic arsenic is approximately two orders of magnitude higher than that of tetratomic arsenic.