Antiphase structures in a periodically inverted GaAs/AlGaAs waveguide investigated by transmission electron microscopy

Abstract

We have performed transmission electron microscopy (TEM) observation of antiphase structures in a periodically inverted GaAs/Al 0.1 Ga 0.9 As waveguide fabricated on a (100) GaAs substrate intentionally misoriented toward ½0 11 by 2°. We have unambiguously confirmed that the artificial (011) boundaries between the inverted and noninverted domains are of antiphase nature by TEM observations including conventional dark-field imaging and a two-beam technique. We also investigated unintentionally formed self-annihilating non-inverted GaAs domains grown on a Ge interlayer introduced for growing inverted GaAs epilayers using the sublattice-reversal epitaxy technique.

Transmission electron microscopy observation of crystal twinning in periodically inverted AlGaAs grown by low-temperature molecular beam epitaxy

“…Here, we note that the antiphase nature (or 90°rotation between the inverted and noninverted domains) of QPM devices fabricated by SRE has been confirmed on the basis of various experimental results. [15][16][17][18]25) Therefore, the unidentified lines in the inverted domains are inferred as 90°rotated (111)A and ð1 1 1ÞA twin planes observed in the noninverted domains. The observation of contrast fringes indicates that the unidentified lines are due to the twin structures in the inverted domain.…”