Asymmetrical Profiles of Ion Implanted Phosphorus in Silicon

Abstract

The concentration profiles of phosphorus implanted into amorphous Si at energies ranging from 150 to 300 keV have been studied by using Secondary Ion Mass Spectrometry (SIMS). It is found that the phosphorus profiles in amorphous Si deviate from Gaussian distributions in the surface region. The concentration profiles are shown to be well fitted by the joined half-Gaussian distributions using the values of the projected ranges, the standard deviations and the third central moments obtained from the measured profiles. The experimental projected ranges are about 10 to 15% smaller than those theoretically calculated. From the data of the projected ranges measured, the electronic stopping power coefficient is evaluated to be 1.4KL.