Depth distribution of gallium ions implanted into silicon crystals

Abstract

Radioactive 72Ga+ ions have been implanted at room temperature into misoriented silicon crystals to a low fluence of 1013 ions/cm2. The resulting depth distribution, measured by anodic stripping, shows a prominent penetrating tail. Previously, such tails have been observed only in high-temperature bombardments and have therefore been attributed to an enhanced diffusion mechanism. It is shown that the scattering of ions into inclined planar or axial channels can account for all the Ga distributions observed. Some consequences for Si device fabrication are discussed.