Influence of chlorine implantation on phosphorus diffusivity and oxidation-induced defects in silicon

Abstract

Chlorine implantation in silicon reduces the phosphorus diffusivity in oxidizing atmosphere and avoids the formation (or strongly reduces the size) of the oxidation induced stacking faults. These effects are evidenced after oxidation in steam atmosphere at the temperatures of 1100 and 1150 °C. These phenomena can be explained by hypothesizing a direct reaction between Cl atoms and silicon interstitials, which results in the reduction of the interstitial supersaturation produced by the oxidation process. On the other hand, the presence of chlorine atoms inside the silicon lattice introduces additional scattering centers, thus reducing the electron mobility; moreover, the formation of secondary defects, mostly dislocations, are observed by electron microscopy after the oxidation step.