Molecular beam epitaxial layers were damaged by using 3MeV proton irradiation and were then annealed. Hall-effect and low-frequency noise measurements were performed, at temperatures of between 77 and 300K, after each step. Several generation-recombination noise components, which were created by proton irradiation, disappeared completely during annealing. The 1/f noise which was created by proton irradiation did not depend upon the measurement temperature. It could be systematically reduced by annealing at temperatures ranging from 543 to 563K. Annealing effects upon the free charge carrier concentration, but not upon 1/f noise, were detected during isochronal annealing. The 1/f noise was attributed to fluctuations in mobility which arose from defect clusters. Annealing of the noise-generating defects was associated with an activation energy of 1eV.

X.Y.Chen, L.C.De Folter: Semiconductor Science and Technology, 1997, 12[10], 1195-201