Measurement of elastic strains and small lattice rotations using electron back scatter diffraction

A method is presented for the determination of elastic strains from electron back scatter diffraction patterns, which are obtained at high spatial resolution, from bulk specimens in a scanning electron microscope. It is estimated that the method is sensitive to strains of the order of 0.02%. Strains in Si1−xGex epitaxial layers grown on planar Si substrates were measured for x from 0.2 to 0.015, there being excellent agreement with X-ray diffraction results. Small lattice rotations can also be measured, the technique being sensitive to rotations of 0.01°, which offers an improvement of approximately two orders of magnitude from the more usual EBSD measurements of misorientation. Small lattice rotations were measured in Si0.85Ge0.15 grown on a patterned Si substrate and were consistent with elastic relaxation of the epilayer strain energy.