Molecular beam epitaxial growth of uniform In0.53Ga0.47As on InP with a coaxial In-Ga oven

Abstract

Epitaxial layers of In0.53Ga0.47As lattice matched to InP substrates have been grown by molecular beam epitaxy. The (100) InP substrate surfaces were first oxide passivated and then thermally cleaned under 1.5×10−6 Torr of arsenic moleuclar beam exposure (i.e., 1.24×1014 As4/cm2 sec). When they were heated to 500 °C, damage-free surfaces without oxygen and carbon contamination were obtained. The surface chemical composition as a function of the thermal cleaning temperature was studied with Auger electron spectroscopy. In0.53Ga0.47As epilayers of highly uniform composition were grown over a 7-cm2 InP substrate using an In/Ga coaxial oven design. Reproducible In and Ga beam fluxes to obtain lattice-match condition were achieved by adjusting the aperture ratio of the In and Ga reservoirs, and the oven temperature. Net electron concentration as low as 3×1015 cm−3 has been achieved for the In0.53Ga0.47As layers.