Natural patterning of templates on GaAs by formation of cracks

Substrate pre-patterning is an effective way to overcome large lattice mismatch and suppress threading defects in the growth of heterostructures. In this work, a new concept was proposed to form natural patterns on commercial substrates monolithically by the formation of surface cracks. Tensile strain was intentionally brought in with a GaAs or GaNAs layer above an InGaAs layer on GaAs substrates. Surface crack patterns successfully formed during the strain relaxation. The strain in a 1 mu m buffer layer atop the pattern was found effectively relaxed. Detailed residual strain distribution was simulated by the finite element method. (C) 2015 Author(s).