POST-IMPLANTATION DEFECTS INSTABILITY UNDER 1 MeV ELECTRON IRRADIATION IN GaAs

Stanis³aw Warcho³1, Henryk Rzewuski1, Janusz Krynicki1, Rainer Grötzschel2

1Department of Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland,
2Forschungszentrum Rossendorf e.V., Postfach 510119 (40/2) 01314 Dresden, Germany

The influence of 1 MeV electron irradiation on the stability of post-implantation defects in GaAs has been investigated. The n-type GaAs wafers of <100> orientation were implanted with 150 keV As+ ions below the amorphization threshold at RT using the implantation dose of 2´1013 ions cm-2 at a constant flux of 0.1 mA cm-2. Then the implanted samples were irradiated with a scanned beam of 1 MeV electrons from a Van de Graaff accelerator in a dose range (0.5-5.0)´1017 cm-2 at 320 K. RBS and channeling spectroscopy of 1.7 MeV 4He+ ions were used to determine the depth distribution of defect concentration before and after 1 MeV irradiations. New results of an "oscillatory" behaviour of the damage level as a function of 1 MeV electron fluence are presented.