Pattern Evolution of Self-Assembled Quantum Dots Under Biaxial Stresses

A stressed epitaxial film can undergo surface instability. The stress field and the interface interaction have profound effects on the dynamics of surface evolution that leads to selfassembled quantum dots. In this paper, by using a nonlinear evolution equation, we investigate pattern evolution of self-assembled quantum dots under general biaxial stresses. It is found that the shape of quantum dots and their spatial ordering are strongly influenced by the relative magnitudes of the biaxial stresses. Linear perturbation analysis and nonlinear numerical simulations are conducted to elucidate the effect of stress anisotropy on the process of selfassembly that selects different patterns.