M.Cervantes^a,b, M. López^a, J. Luyo^a, M. Meléndez^a. ^aDepartamento de Física, CINVESTAV-IPN. Apartado Postal 14-740, México, D.F. ^bDepartamento de Biofísica y Fisiología UPIBI-IPN. Av. Acueducto de Guadalupe s/n Barrio la Laguna Ticomán, México, D.F. 07340

M. Tamura and Y. Hiroyama. Joint Research Center for Atom Technology, Angstrom Technology Partnership (JRCAT-ATP), 1-1 4-4 Higashi, Tsukuba, Ibaraki 305-0046, Japan.

In this work we present a study of the optical and structural properties of GaN films grown by RF plasma-assisted molecular beam epitaxy on Si substrates. The samples were deposited using a variety of growth conditions on Si(001) and Si (111) substrates. In order to promote the epitaxial growth of the GaN cubic fase, a very thin (~2.5 nm) SiC buffer layer was used¹. The films were characterized by in-situ reflection high-energy electron diffraction (RHEED), x-ray diffraction, atomic force microscopy, and photoreflectance (PR). We will discuss the optical characteristics in terms of the structural properties of the films grown on under different growth conditions.

1. Y. Hiroyama and M. Tamura, Jpn. J. Appl. Phys. 37, L630 (1998).