ABRUPTNESS OF GAAS/ALINP HETEROINTERFACES GROWN BY GS-MBE

The effect of the exposure of GaAs and AlInP surfaces to phosphorus and arsenic beams were studied using HR-TEM, RHEED, XPS, AES, and Raman scattering. The GaAs surface was found to be fairly reactive with respect to the phosphorus beam. The exposure of GaAs to a phosphorus beam for 60 s caused a surface roughness of at least 20 angstrom, caused by the formation of a GaP-rich island. However, a flat surface of AlInP was found to be structurally stable with respect to the arsenic beam. The arsenic beam was found to induce a replacement of a few percent of P atoms by As atoms in an AlInP surface layer. An atomically flat AlInP-on-GaAs interface was obtained by a sequence in which the GaAs surface was not exposed to a P beam.