Raman microprobe analysis of stress in Ge and GaAs/Ge on SiO2-coated Si substrates

Publisher Website
Google Scholar
Abstract
Stress and strain in single‐crystal Ge and GaAs/Ge films grown on SiO2‐coated Si substrates have been investigated through the Raman microprobe analysis. The Ge film is found to be subject to a tensile stress of (3.4–6.1)×109 dyne/cm2 and a strain of (2.4–4.3)×10−3 without distinguished spatial variation within a SiO2 island. The stress agrees well with that evaluated from the GaAs electroluminescence spectral shift with the deformation‐potential model. The strain can be attributed dominantly to the thermal expansion difference between the Ge and the substrate Si. A large Raman spectral shift to the lower frequency side and a large linewidth for Ge have been observed in the seeding opening region, which represents Ge lattice disorder in this region.