TEM evaluation of strain and stress in III-V semiconductor epitaxial structures Proceedings Paper

Rocher, A, Cabié, M, Ponchet, A et al. (2004). TEM evaluation of strain and stress in III-V semiconductor epitaxial structures . PHYSICA STATUS SOLIDI A-APPLIED RESEARCH, 201(2), 357-363. 10.1002/pssa.200303969

cited authors

  • Rocher, A; Cabié, M; Ponchet, A; Arnoult, A; Bedel-Pereira, E

authors

abstract

  • A new method of determination of the stress induced by a misfit between an epilayer and its substrate is presented. It is based on the experimental measurement of the specimen curvature induced on the bilayer by this misfit stress. The curvature radius, the misfit stress and the thicknesses of the epilayer and the substrate are related by the Stoney formula. Then from the determination of the radius of curvature and the thickness of the substrate we are able to determine the misfit stress. The originality of the method is to measure locally these parameters on specimen thinned for Transmission Electron Microscopy (TEM). For a thickness of TEM specimen of about 0.3 μm, the measured radius of curvature is about 100 μm for a lattice mismatch of 1% and an epilayer thickness of 10 nm. This method has been applied to the GaInAs/GaAs system with an In concentration of 20% and a lattice mismatch of 1.4%. The uniformity of the misfit strain is evaluated at the sub-micrometer scale. Experimental values of the misfit strain obtained by this method are 10 to 40% lower than the theoretical values. This difference is discussed in term of In segregation and chemical gradient at the level of the interface. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

publication date

  • January 1, 2004

published in

Digital Object Identifier (DOI)

start page

  • 357

end page

  • 363

volume

  • 201

issue

  • 2