ULTRAFAST CARRIER TRAPPING IN HIGH-ENERGY ION-IMPLANTED GALLIUM-ARSENIDE

Time resolved photoluminescence and electrical measurements were made on MeV As, Ga, Si, and O ion implanted GaAs to doses in the range of 1 x 10(14)-5 x 10(16) cm (-2) and subsequently annealed at 600 degrees C for 20 min under arsine ambient. Carrier trapping times were found t o decrease with increase in implantation dose for all species studied and can be shorter than 1 ps. Sheet resistance values were found to be independent of implantation dose and were of the order of 10(8) Ohm/s quare for As, Ga, and O implantation and similar to 2x10(2) Ohm/square for the Si case due to its electrical activation. Conductivity activa tion energies of 0.67-0.69 eV were observed for As, Ga, and O ion impl anted and annealed GaAs, which are close to the reported activation en ergy for annealed low-temperature GaAs (0.65 eV). (C) 1996 American In stitute of Physics.