Depth distribution of Mn in Mn doped GaAs using secondary ion mass spectrometry

Abstract

Secondary ion mass spectrometry (SIMS) was used for depth distribution analysis of Mn in GaAs formed by ion implantation of Mn in GaAs single crystal wafers at an implant energy of 300 keV, followed by laser pulse heating to anneal out the radiation damage. Mn doped GaAs, due to its ferromagnetic behavior, has potential applications in spintronic devices. Knowledge of the quantitative depth distribution, diffusion and segregation of these dopant atoms in the host material are necessary for fabrication of these devices. The depth distribution of Mn was carried out using oxygen and cesium primary ion beams at various impact energies. The obtained depth profiles of Mn demonstrated that Mn was uniformly distributed in as-implanted and single shot laser annealing samples, whereas in case of double shot annealing, segregation effect of Mn atoms toward the decaying trail of the distribution curve was observed, thanks to extremely high detection sensitivity of SIMS. Relative sensitivity factors of Mn in GaAs were determined for oxygen and cesium primary ion beams using as-implanted samples at various impact energies under the optimized analysis conditions, retaining the high depth resolution. Surface distribution of Mn was carried out using SIMS, which revealed uniform lateral distribution of Mn in as-implanted as well as laser annealed samples.