(AIAs)1/2(GaAs)1/2 fractional-layer superlattices (FLSs) are grown on (001) vicinal substrates by metalorganic chemical vapor deposition. Various kinds of GaAs substrates are used. When the substrate is misoriented to  direction by 1.92° and  by 0.10°, uniform superlattice periods in a large surface area are observed with a bright field transmission electron microscope (TEM). The results suggest ideal crystal growth from kink sites during MOCVD growth, and the distances between the kink sites are equal.
On a substrate misoriented to  by 1.90°, the superlattice periods exhibit an undulation. This shows that kink flow mode growth is not dominant in the  direction. On a substrate misoriented to [010[ by 2.0°, no superlattice periods were observed. From the above results, we discuss the growth mechanisms.
Polarization dependent photolumlnescence and optical absorption spectra of FLS were also observed. Electron wave interference devices with lateral periodic potential were fabricated.