Regularities in the formation of dislocation networks on the boundary of bonded Si(001) wafers

The dislocation networks in structures with hydrophilically bonded Si (001) wafers are investigated by transmission electron microscopy. Networks with differing geometry and type of dominant dislocations are observed. One type of networks, which is typical of bonded structures, is formed on the basis of a square network of screw dislocations and contains a system of unidirectional 60$^\circ$ zigzag-shaped dislocations. It is established that such dislocation networks are flat in structures with an azimuthal misorientation of wafers exceeding 2$^\circ$, whereas they are three-dimensional at smaller misorientation angles. A unique network of another type is formed only by 60$^\circ$ dislocations, the majority of which are extended along one direction, which does not coincide with the $\langle$110$\rangle$ directions in the boundary plane and has a number of specific features, the explanation of which is impossible within the framework of conventional representations.