InxGa1−xAs/InP selective area metal-organic vapor phase epitaxy for non-magnetic semiconductor spintronics

We carried out selective area metal-organic vapor phase epitaxy (SA-MOVPE) of In-rich InxGa1−xAs/InP modulation-doped heterostructures in an N2 atmosphere. The aim is to obtain wire structures which exhibit strong spin–orbit coupling without using etching of the heterostructures for their fabrication. The wire geometry was studied as a function of mask opening width. The transport properties were determined at 0.5 K and up to 10 T magnetic field. A clear growth enhancement was confirmed as the initial opening width decreases; thus, the InGaAs as well as the total thicknesses became larger. Moreover, we confirmed the top width saturates in some narrower wires due to geometrically limited growth by facets. Some narrower wires showed high resistivity, which might originate from structural deterioration in In0.77Ga0.23As due to the growth enhancement and/or non-uniformity of the parallel wires. On the other hand, wider wires showed Shubnikov–de Haas (SdH) oscillations, which exhibited SdH beating patterns. All in all it is possible to achieve strong spin–orbit coupling in InxGa1−xAs/InP wires produced by SA-MOVPE.