Strained interface of lattice-mismatched wafer fusion

A model has been developed for the periodic strain field near the wafer-fusion interface of lattice-mismatched single crystals. A solution has been found that satisfies the elastic mechanical equilibrium and the boundary conditions. It reveals a wavy interface with the amplitude of the atomic displacement rapidly decaying a short distance from the interface. The model is consistent with the experimental observations of nearly defect-free material except at the interface. The strong alternating strains along the interface have implications for its electronic energy-band structure and electrical characteristics.