Ion implantation into gallium arsenide

Secondary-ion-mass-spectrometry studies of the implantation profiles of 20- to 400-keV Si, Se, and Be ions into GaAs are reported. The measured profiles are fit with Pearson-IV distributions whose moments are fit to functions of the ion energy to obtain simple, widely applicable analytical formulas. Also, profiles are measured for varying wafer tilt and rotation angles to the ion beam, and for varying dislocation densities and doses. For implantation through dielectric caps, the profiles in the GaAs can be simulated using shifted, bare-wafer Pearson-IV distributions for Be, or mixtures of shifted Pearson-IV and Gaussians for Si and Se. Also, knock-on distributions of Si and O atoms resulting from implanting through SiO₂ caps were measured.