Generation Rule of the Slip Dislocation in LEC GaAs Crystal

In a (001) low dislocation density wafer, an eight-fold circular strain field was observed near the periphery between <110> and <100> radii. The observed result was explained from the viewpoint of ease of slip dislocation generation by calculation of Schmid factor magnitude distribution under the condition that major thermal stress was applied to tangential direction at the round ingot surface. While, in a (001) high dislocation density wafer, a four-fold strain field was observed around the <100> radii. The result was explained by intersection of slip dislocation generated from eight positions at the periphery between <110> and <100> radii as well.