ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The effects of residual ion damage in low-energy (30 eV–30 keV) C+-doped GaAs were investigated with regard to the electrical and optical activation of C as a function of C+ ion acceleration energy EC+. Systematic variation of EC+ demonstrated that, in the energy range of EC+〈170 eV, the net hole concentration (|NA−ND|) slightly increases as EC+ increases and the highest |NA−ND| was obtained at EC+=170 eV under the constant C+ ion-beam current density. For EC+(approximately-greater-than)170 eV, an increase in EC+ gave rise to an abrupt decrease of |NA−ND| down to two orders of magnitude smaller than that obtained at EC+=170 eV. In low-temperature (2 K) photoluminescence spectra for as-grown samples with EC+=240 and 350 eV, a novel emission ascribable to residual ion damage was observed instead of an essential acceptor–acceptor emission of [g−g]β. However, subsequent annealing at 850 °C made this novel emission disappear and the proper [g−g]β emission was merely observed. An activation process observed for EC+=5, 10, and 30 keV samples was very similar to that by high-energy ion implantation, indicating low activation rate of 10%–15%. Minority-carrier lifetime measurements using scanning tunneling microscope stimulated time-resolved luminescence demonstrated the presence of residual ion damage in as-grown samples at EC+=240 and 350 eV and annealed ones at EC+=5, 10, and 30 keV while no ion damage was observed in as-grown sample at EC+=30 eV. The incorporation and activation behaviors of C atoms that take the form of low-energy ions were found to be considerably affected by changes in ion–surface interaction with increasing EC+ and by the presence of residual ion damage in the layer. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.363306
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