Effect of rapid thermal annealing on ion-implanted and neutrontransmutation doped GaAs

Raman spectroscopy with optical multichannel detection was used to study Se(+)-ion implanted and neutron-transmutation doped GaAs, both before and after rapid thermal annealing. Samples implanted at room temperature showed an amorphous surface layer, whereas those implanted at 320 degrees C exhibited Raman features of both amorphous and crystalline GaAs. After rapid thermal annealing, the material implanted at elevated temperatures showed a better structural recovery, as indicated by a lower intensity of forbidden phonon scattering. Using resonance Raman effects, we were able to discriminate between amorphous and crystalline features in the spectra. For the neutron-transmutation doped GaAs, the as-irradiated material showed a Raman spectrum similar to the one of undoped crystalline GaAs. The increase in electrical activation with increasing annealing temperature was monitored by Raman scattering from coupled plasmon-phonon modes, giving a carrier concentration comparable to the one obt ained from Hall measurements. (IAF)