A Structural and Electrical Comparison of BCl and  BF 2 Ion‐Implanted Silicon

Abstract

The molecular ions and are implanted into <100> silicon at an energy of 16 keV per boron atom in the dose range of to form shallow p+/n junctions. Cross‐sectional transmission electron microscopy shows that chlorine is at least four times as effective as fluorine in amorphizing silicon. The increase in thickness of the amorphous layer, however, has a small effect in the reduction of axial channeling of boron as measured by secondary ion mass spectrometry. After annealing for 30 min at 900°C, diffusion of interstitial boron is enhanced by chlorine relative to fluorine, whereas the electrical activity of boron is inhibited. Diodes made with both and implantations have comparable I‐V characteristics with low reverse‐bias junction leakage currents that are not affected by a band of dislocation loops which remain near the original amorphous‐crystalline interface.