Gas-Source Molecular Beam Epitaxy of GaNxAs1-x Using a N Radical as the N Source

We propose the application of GaNAs as a novel material fabricated on a Si wafer. It is a direct-transition type semiconductor, and can be lattice-matched to Si. Therefore, it is valid for use in the active region of light-emitting devices fabricated on Si. In this letter, GaNAs with a low N content is grown on a GaAs wafer to explore the gas-source molecular beam epitaxy under which a N radical is used as the N source. As a consequence, GaNAs with a N content up to 1.5% is grown, even though the conductance of the N-radical beam cell is fixed at a very low value. The bowing parameter of the bandgap is experimentally evaluated at 18 eV.