Silicon and phosphorus co-implantation into undoped and indium-doped GaAs substrates

The electrical properties and low-temperature (4.2 K) photoluminescence of heavily doped n-type layers produced by silicon and silicon/phosphorus implantation into undoped and indium-doped Czochralski grown semi-insulating GaAs substrates have been investigated. It is found that Si+P co-implantation results in suppression of deep levels in the anion sublattice, an increase of donor activation efficiency, and a sharper carrier concentration profile in both types of substrates. The use of indium-doped substrates enhances radiation defect annealing, but does not change the donor activation efficiency