REDUCTION OF THE DEGREE OF CONDUCTIVITY COMPENSATION IN EPITAXIAL N-INP FILMS BY FAST-ELECTRON BOMBARDMENT

The temperature dependence of the electrical properties of pure epitax ial InP films (with an electron density n almost-equal-to 2 X 10(14) c m-3 at 300 K) has been studied before and after bombardment with fast electrons (the electron energy was E = 3.5-4 MeV). The degree of condu ctivity compensation has been found to decrease with increasing bombar dment dose over the interval 1 X 10(15)-1 X 10(17) cm-2, while the con ductivity activation energy for the films increases from 0.33 to 0.41 eV. The behavior observed here is explained in terms of a predominant accumulation of radiation-induced defects of the donor type, with an i onization energy congruent-to 0.4 eV, in the InP lattice during the el ectron bombardment.