X-Ray Observations of Defect Structures in Silicon Crystals

Abstract

The structure of defects in silicon crystals, which causes X-ray double images, was studied in detail by the X-ray diffraction topography and the etching technique. Generation of these defects was found to be closely related to growing conditions of the crystal, particularly to the condition of hydrogen gas flow used as an ambient. A pair of parallel etch pit arrays was observed on an etched surface and was confirmed to have one-to-one correspondence to the double image. When a specimen was annealed in the range from 700°C to 1000°C, the double image showed fine structures, which could be only observed by using softer radiation, CuKα₁. Two types of dislocation loops were generated from the defect corresponding to the double image when a specimen was annealed at 1200°C. The origin and the mechanism of formation of the defect was discussed.