X-Ray Micrographic Observation of Imperfections in Si Wafer near the Oxide Film Edge before and after the Localized Diffusion

Imperfections in the region near the edge of oxide film on a silicon wafer was observed by the use of a Lang camera. Before diffusion, an elastic strain field caused by the oxide film edge was observed in the region near the edge. As the impurity concentration of localized diffusion became high, the state in this region changed, showing that the diffusion process caused a strain, and generated dislocation arrays. It was found that inhomogeneity of distribution of diffusion-induced strain at the edge and inside the diffused region near the edge is very likely responsible for the formation of these dislocation arrays.