Analysis of Be doping of InGaP lattice matched to GaAs

We present a study on the growth of Be-doped InGaP layers lattice matched t o GaAs substrates by chemical beam epitaxy. We show that the presence of th e dopant affects not only electrical but the structural properties - crysta l quality and morphology - as well. For samples grown at higher temperature s, a saturation of the electrical carrier concentration is observed, associ ated to degradation of surface morphology and crystal quality. Our results suggest that at these higher temperatures the excess of Be atoms - which ar e not electrically active - are incorporated as microcrystals of Be3P2 whic h may give rise to defects in the layers. Reducing the growth temperature c an alter this scenario, resulting in Be-doped InGaP layers with improved cr ystal quality, planar morphology and no saturation in the electrical carrie r concentration for Be concentrations up to 3 x 10(19) cm(-3). (C) 2000 Els evier Science B.V. All rights reserved.