SeGe/Si mesas - Strain Mapping
secondary electron image

The mismatch in lattice parameter between SiGe alloys and Si can lead to very high levels of elastic strain (ie stress). Growth of SiGe on Si mesa pads of small dimension can lead to significant relaxation of the stresses because the lateral constraint has been removed. We have used cross-correlation based analysis of EBSD patterns to determine the strain distribution and lattice rotation in such structures. All six components of the strain tensor and lattice rotations about all three axes are obtained, giving tremendous detail concerning the deformed state of the structure.

e11 strain
normal strain e11
e22 strain
normal strain e22
e33 strain
normal strain e33
e12 strain
shear strain e12
e23 strain
shear strain e23
e31 strain
shear strain e31
w12 rotation
rotation w12
w23 rotation
rotation w23
w31 rotation
rotation w31
angular error
estimated error (rads)
peak height
cross correlation peak height
Contact: Angus Wilkinson

Mapping strains at the nanoscale using electron back scatter diffraction
AJ Wilkinson, G Meaden, DJ Dingley
Superlattices and Microstructures, (2009), vol. 45, 285-294
High resolution measurements of strain and tilt distributions in SiGe mesas using electron backscatter diffraction
Wilkinson AJ
Applied Physics Letters, (2006), vol. 89, 241910