Investigation of the relaxation behaviour of epitaxially grown wire structures by means of Monte‐Carlo‐Simulation

Abstract

We present results on the elastic relaxation behaviour of II-VI and III-V wire structures. The structures were obtained by wet etching of extended layers as well as shadow mask assisted Selected Area Epitaxy (SAE). The SAE wire structures are especially interesting since they are grown directly, do not require treatment after the growth process, and posess the ability to relax elastically during growth. Reciprocal space maps of strained semiconductor structures, obtained by High Resolution X-ray Diffraction (HRXRD) have so far been interpreted in the context of bulk elastic properties. In this contribution we introduce a relaxation procedure based on interatomic potentials. The wire structure is simulated with atomic resolution atop of the substrate material. A Monte-Carlo algorithm is applied to relax the structure while minimizing the strain energy. The reciprocal space maps calculated from the relaxed structure are in good agreement with the observed HRXRD maps. Hence we can interprete the strain state of the wire structures with atomic resolution.