Strain Relaxation of Patterned Ge and SiGe Layers on Si

It was found that patterning of Ge and SiGe layers on Si(001) substrates principally leads to the strain anisotropy. The striped mesa structure readily induces elastic relaxation of the strained Ge and SiGe. Furthermore, a clear difference of strain relaxation mechanism depending on the dislocation introduction was confirmed. Introduction of 60deg dislocations is sensitive to the shape of patterned region, resulting in the anisotropic strain. On the other hand, the pure-edge dislocation network explicitly leads to isotropic strain relaxation even in the miniaturized region