Steady state implantation of nitrogen ions into GaAs and subsequent annealing can lead to the formation of optical active centres. The concentration of the implanted nitrogen depends inversely on the sputter yield of GaAs by the nitrogen ions. Therefore, it is advantageous to use low energy ions. Most of the experimental measurements of implanted ion ranges have been done for high energy heavy ions.
The ranges and equilibrium concentration of low energy (0.5 to 5 keV) nitrogen ions implanted in GaAs were experimentally determined. The surface concentrations, as a function of nitrogen ion
energy, were determined with Auger electron spectroscopy using standard spectra, and are compared to the Schulz-Wittmaack model [1]. The nitrogen ranges were determined by 500 eV argon sputter depth profiling and are compared to the predictions of commonly accepted range theories. The experimentally determined ranges were also compared to the results obtained using various simulation codes e.g. TRIM, MARLOWE, PRAL and TRIDYN.
[1] F. Schulz and K. Wittmaack, Rad. Eff. 29 (1976) 31. |