Difference in radiation-induced damage of GaAs caused by P and Al ion implantation

Results of investigating defect formation by the channelled ion backscattering method in gallium arsenide crystals implanted at low (40 K) and room (293 K) temperatures with 60 keV phosphorus and aluminium ions in a wide dose range from 1012 to 1016 ion/cm2 are presented and discussed. Dynamics of GaAs radiation damage with P and Al ions at 40 K is very similar. Complete disordering of an implanted layer is reached at a dose of approximately 5x1013 cm-2. In dose dependences of GaAs damage with P and Al ions implanted at Tsub(room) there are three stages characterized with different velocities of the defect accumulation. The implanted layer amorphization occurs during the implantation of P+ and Al+ ion fluxes at doses of approximately 3x1014 and approximately 4x1015 cm-2, accordingly. Crystal damage dose dependences obtained for the first time at different temperatures permit to consider the differences in the chemical character of P and Al atoms implanted into gallium arsenide one of main factors which result in considerable differences in the damage level of the given material with P and Al ions