V-Groove Si Nanopatterning for the Direct Epitaxy of Orientation-Patterned III-V Nonlinear Optical Crystals: Article No. 2400996

Orientation-patterned (OP) III-V semiconductors-used as quasi-phase-matched crystals for nonlinear optics applications-are typically epitaxially grown on expensive III-V substrates using a complex process requiring three separate epitaxy steps. In this work, a method is demonstrated for growing orientation-patterned III-V crystals on Si substrates through V-groove nanopatterning and a single epitaxial growth. V-groove Si allows for suppression of random antiphase domain formation that is typical of III-V growth on (001)-oriented Si through the use of (111)-faceted trenches patterned on (001)-oriented Si substrates. By alternating the directions of the V-groove trenches between [110] and [1 0], antiphase boundaries can be selectively induced at the boundaries between the two directions of trenches due to the difference in symmetry between the III-V material and Si. This approach allows for a greatly simplified process for growing OP-III-Vs and more broadly is a new, robust approach for precisely patterning antiphase boundaries of arbitrary shape and length scales down to 50 nm.