Atmospheric pressure metal-organic vapour phase epitaxy of InP, (GaIn)as, and (GaIn)(AsP) alloys

Abstract

An introduction to optical communications and opto-electronic devices is given, which demonstrates the motivation for research into III/V devices, and materials. Different epitaxial growth techniques are compared, an introduction to Metal-Organic Vapour Phase Epitaxy (MOVPE) is given, and the author's reactor is described. The reaction chemistry of MOVPE is discussed and results from studies of the passivation of p-type InP are used to confirm the surface nature of reactions. Results upon the background doping of MOVPE grown InP and the effect of growth conditions are discussed. High electron mobility results from InP layers are presented. The growth of epitaxial alloy layers of (Galn)As and (GaIn)(AsP) is described with particular reference to crystallinity, lattice matching and composition control. A novel method of monitoring the dynamic vapour pressure of metal alkyls is described, and theoretical and practical results upon the factors affecting gas mixing and alloy uniformity are presented. Results on the intentional doping of epitaxial layers with dimethylzinc, hydrogen selenide, and silane and the effect of varying the growth conditions are presented; and the use of other dopants is reviewed. The passivation of zinc acceptors by hydrogen in p-type InP is reported and discussed in detail. Results upon the use of ferrocene as a semi-insulating dopant are presented and the literature is reviewed. Photoluminescence and transmission electron microscopy results are presented upon the growth of low dimensional structures, containing layers of less than lOOA thickness. Systematic studies of growth conditions are reported which have led to an understanding of the factors affecting hetero-interface abruptness. Experimental results are reported upon distributed feedback lasers and all MOVPE double heterostructure and ridge waveguide lasers. A discussion on safety aspects of MOVPE is included, with particular reference to the toxicity of arsine and phosphine, and the prevention of environmental pollution.