Finite element analysis on stress distribution in buried quantum dots

The stacked, self-assembled and vertically aligned quantum dot superlattices are fabricated by alternating growth of substrate and epitaxial materials, the stress/strain fields in the buried quantum dots can influence their optical and piezoelectric properties and mechanical stability. The distributions of stresses, strains, hydrostatic strains and biaxial strains in buried strain self-assembled Ge/Si semiconductor quantum dot are investigated based on the theory of anisotropy elasticity and also compared with those of free-standing quantum dot. The sameness and difference of the stresses/strains between the buried and the free-standing quantum dots, and the influence of cap layer on the stress/strain fields in quantum dots are given.