Correlation of electrical carrier and atomic profiles of Mg implants in GaAs

Abstract
A comparative study of secondary ion mass spectrometry (SIMS) atomic profiles and electrical carrier profiles by Hall measurements has been carried out for Mg-implanted GaAs. It has been found that as-implanted Mg profiles in GaAs do not follow simple Gaussian distributions, but can be fitted to type-IV Pearson distributions. For low dose, implanted Mg does not redistribute significantly during annealing at 750 °C, whereas for high dose, Mg is found to diffuse out substantially. In general, the electrical carrier profiles follow roughly the SIMS atomic profiles of annealed samples. It is believed that the outdiffusion of Mg is chiefly responsible for poor electrical activation efficiency at high doses.