Formation and characterization of locally strained Ge1−xSnx/Ge microstructures

• Main Authors: Ike, Shinichi, Moriyama, Yoshihiko, Kurosawa, Masashi, Taoka, Noriyuki, Nakatsuka, Osamu, Imai, Yasuhiko, Kimura, Shigeru, Tezuka, Tsutomu, Zaima, Shigeaki
• Format: Conference Proceeding
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Epitaxial growth; Exact sciences and technology; Finite element method; Germanium; GeSn; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Physical properties of thin films, nonelectronic; Physics; Strain; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thin film structure and morphology; Tin; X-ray microdiffraction
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.08.126

In this study, we have examined the formation of uniaxially strained Ge microstructures with embedded Ge1−xSnx epitaxial layers and the microscopic local strain structure in Ge and Ge1−xSnx using synchrotron X-ray microdiffraction and the finite element method. We achieved local heteroepitaxial growth of Ge0.947Sn0.053 layers on the Ge recess regions. Microdiffraction measurements reveal that an average uniaxial compressive strain of 0.19% is induced in Ge locally with Ge1−xSnx stressors. In addition, we found that the Sn precipitation near the Ge1−xSnx/Ge(001) interface occurs after post-deposition annealing at 500°C without the introduction of dislocation. It is considered that the local Sn precipitation occurs preferentially due to the larger residual stresses near the Ge1−xSnx/Ge interface. •The formation of locally strained Ge microstructure with GeSn layer was achieved.•We investigated the local strain structure in GeSn/Ge by X-ray microdiffraction.•The microdiffraction measurement reveals that the local strain is induced in Ge.•The non-uniform stress distribution in GeSn can induce the local Sn precipitation.