Dislocation structure in low-angle interfaces between bonded Si(001) wafers

Abstract

Dislocation structures of interfaces between bonded (001) Si wafers with co-existing low-angle twist and tilt misorientations were studied by transmission electron microscopy. At dominating twist, a square screw dislocation network accommodates the twist, and interacts with steps at the interface, forming 60-degree dislocations. As the step density, i.e., the tilt angle, increases relative to the twist angle, the density of so-called zigzag reactions increases. Finally, hexagonal dislocation meshes dominate the dislocation configuration. It was found that the plan-view observations give the crystallographic relations accurately. The structures of the dislocation configurations were analyzed using Bollmann's dualistic representation. The rotation axes and angles were determined.