Growth of cubic GaN by molecular-beam epitaxy on porous GaAs substrates

It is shown that GaN layers can be grown on (100)- and (111)- oriented poro us single-crystal GaAs substrates by molecular-beam epitaxy with plasma act ivation of the nitrogen by an rf electron cyclotron resonance discharge. Th e resulting undoped epitaxial layers possessed n-type conductivity with a c arrier concentration similar to 10(18). Data obtained by scanning electron microscopy and cathodoluminescence indicate that at thicknesses similar to 2000 Angstrom, continuous layers of the cubic GaN modification are obtained regardless of the substrate orientation. (C) 1999 American Institute of Ph ysics. [S1063-7850(99)00101- 9].