Improved precision in strain measurement using nanobeam electron diffraction

Improvements in transmission electron microscopy have transformed nanobeam electron diffraction into a simple and powerful technique to measure strain. A Si0.69Ge0.31 layer, grown onto a Si substrate has been used to evaluate the precision and accuracy of the technique. Diffraction patterns have been acquired along a ⟨110⟩ zone axis using a FEI-Titan microscope and have been analyzed using dedicated software. A strain precision of 6×10−4 using a probe size of 2.7 nm with a convergence angle of 0.5 mrad has been reached. The bidimensional distortion tensor in the plane perpendicular to the electron beam has been obtained.

[1]  A. G. Cullis,et al.  Application of convergent beam electron diffraction to two-dimensional strain mapping in silicon devices , 2003 .

[2]  D. Gerthsen,et al.  Quantitative determination of lattice parameters from CBED patterns: accuracy and performance , 1998 .

[3]  R. Pantel,et al.  Strain measurements by convergent-beam electron diffraction: The importance of stress relaxation in lamella preparations , 2004 .

[4]  F. Hüe,et al.  Nanoscale holographic interferometry for strain measurements in electronic devices , 2008, Nature.

[5]  E. Sarigiannidou,et al.  Theoretical discussions on the geometrical phase analysis. , 2005, Ultramicroscopy.

[6]  J. Hartmann,et al.  SiGe growth kinetics and doping in reduced pressure-chemical vapor deposition , 2002 .

[7]  Dmitri O. Klenov,et al.  Strain relaxation in transistor channels with embedded epitaxial silicon germanium source/drain , 2008 .

[8]  M. Casanove,et al.  Quantitative analysis of HOLZ line splitting in CBED patterns of epitaxially strained layers. , 2006, Ultramicroscopy.

[9]  T. Numata,et al.  Strain evaluation of strained-Si layers on SiGe by the nano-beam electron diffraction (NBD) method , 2005 .

[10]  Shinichi Takagi,et al.  Strain relaxation of strained-Si layers on SiGe-on-insulator (SGOI) structures after mesa isolation , 2004 .

[11]  O. Krivanek,et al.  Developments in EELS instrumentation for spectroscopy and imaging , 1991 .

[12]  V. Senez,et al.  Techniques for mechanical strain analysis in sub-micrometer structures: TEM/CBED, micro-Raman spectroscopy, X-ray micro-diffraction and modeling , 2003 .

[13]  F. Hüe,et al.  Direct mapping of strain in a strained silicon transistor by high-resolution electron microscopy. , 2008, Physical review letters.

[14]  G. Gazzadi,et al.  Electron diffraction with ten nanometer beam size for strain analysis of nanodevices , 2008 .