Lateral extent of oxidation-enhanced diffusion of phosphorus in 〈100〉 silicon

Abstract
The lateral extent of oxidation‐enhanced diffusion (OED) of phosphorus in (100) silicon oxidized in dry oxygen has been investigated. OED was observed near the Si/SiO2 interface under an oxidation mask composed of Si3N4/SiO2. It was found that under the mask OED decays nearly exponentially from the edge of the oxidized region. The characteristic decay length increases with square root of oxidation time and is exponentially dependent on temperature with activation energy of 2 eV. It is proposed that the OED observations can be explained on the basis of excess silicon self‐interstitials diffusing away from the oxidized regions. Both diffusion and interface capture of self‐interstitials play a role in their distribution in the silicon bulk.