Nanoepitaxy of GaAs on a Si(001) substrate using a round-hole nanopatterned SiO2 mask

GaAs is grown by metal-organic vapor-phase epitaxy on a 55 nm round-hole patterned Si substrate with SiO2 as a mask. The threading dislocations, which are stacked on the lowest energy facet plane, move along the SiO2 walls, reducing the number of dislocations. The etching pit density of GaAs on the 55 nm round-hole patterned Si substrate is about 3.3 x 105 cm(-2). Compared with the full width at half maximum measurement from x-ray diffraction and photoluminescence spectra of GaAs on a planar Si(001) substrate, those of GaAs on the 55 nm round-hole patterned Si substrate are reduced by 39.6 and 31.4%, respectively. The improvement in material quality is verified by transmission electron microscopy, field-emission scanning electron microscopy, Hall measurements, Raman spectroscopy, photoluminescence, and x-ray diffraction studies.