Relaxed and Strained Patterned Germanium-Tin Structures: A Raman Scattering Study

We report the first realization of fully-released and relaxed Ge1-xSnx structures on Ge substrate. The coefficients of Raman peak shift a and b due to the alloy disorder and strain, respectively, were experimentally obtained for Ge1-xSnx. In addition, to lower the Sn composition needed to achieve direct bandgap Ge1-xSnx alloys and also to realize channel materials with higher electron mobility, uniaxially tensile strained Ge1-xSnx patterns were fabricated. Large tensile strain (>1%) was detected in the patterned Ge1-xSnx lines. Such tensile-strained Ge1-xSnx structures could enable the realization of Group-IV optoelectronic devices and high mobility n-channel transistors. (C) 2013 The Electrochemical Society. All rights reserved.