Thermal stability of the electrical isolation in n-type gallium arsenide layers irradiated with H, He, and B ions

The stability of the electrical isolation in n-type GaAs layers irradiated with ions of different mass is compared. The irradiations were performed with proper doses of H+1, He+4, or B+11 ions to create specific damage concentration level which lead to: (i) the trapping of practically all the carriers (Rs ≈108 Ω/□), (ii) the onset of hopping conduction (Rs ≈108 Ω/□), and (iii) a significant hopping conduction (Rs ≈106 Ω/□). Irrespectively of the ion mass, the temperature range for which the isolation is preserved, i.e., Rs >108 Ω/□, extends up to 200 or ≈ 600 °C, respectively, for the cases (i) and (ii). In case (iii), this range comprises temperatures from ≈ 400 to 650 °C. Annealing stages at 200 and 400 °C recover in a great extent the conductivity and improve the carrier mobility in low dose irradiated samples [case (i)]. In samples irradiated to higher doses [cases (ii) and (iii)], the conductivity recovers in a single stage.