Formation of n(+)-layers in undoped and indium-doped GaAs wafers by Si and Si+P ion implantation

We have studied electrical properties and low-temperature photoluminescence of n(+)-layers produced by Si and Si+P ion implantation into undoped and indium-doped liquid encapsulated Czochralski (LEG) grown GaAs semi-insulating (SI) substrates. The effects of implant dosage are considered. It is shown that when compared to Si-only implantation, the Si+P co-implantation leads to suppression of the deep level defect formation in the anion sublattice, increasing the donor activation efficiency and obtaining: a sharper concentration profile of implanted atoms in both types of substrates. An additional improvement in radiation defect annealing can be obtained using indium-doped GaAs matrix. However, no extra enhancement in donor activation efficiency due to In-doping was observed.