X-ray study of lateral strains in ion-implanted silicon

Lateral strains induced by 80 keV argon ion implants into silicon have been studied using X-ray interferometry and X-ray diffraction topography. The stressed state is described by the expansion of a thin surface layer, and it is shown, how it will affect the dilatational moiré patterns observed in the interferograms. The integrated stress acting in the damaged layer has been studied as a function of the bombardment dose. A maximum is reached at a dose of about 2×10¹⁴ ions/cm². The maximum local stress is of the order of 1×10⁹ dyn/cm².