GaMnN dilute magnetic semiconductor samples, prepared by metalorganic chemical vapor deposition, are shown to exhibit ferromagnetism or even paramagnetism depending upon the type and concentration of extrinsic impurity present in the film. In addition, GaMnN deposited using growth parameters normally yielding a nonferromagnetic film becomes strongly ferromagnetic with the addition of magnesium, an acceptor dopant. Based upon these observations, it seems that ferromagnetism in this material system depends on the relative position of the Mn energy band and the Fermi level within the GaMnN band gap. Only when the Fermi level closely coincides with the Mn-energy level is ferromagnetism achieved. By actively engineering the Fermi energy to be within or near the Mn energy band, room temperature ferromagnetism is realized.

We report on the dependence of ferromagnetic properties of metalorganic chemical vapor deposition grown GaMnN films on carrier transfer across adjacent layers. We found that the magnetic properties of GaMnN, as a part of GaMnN∕GaN:Mg heterostructures, depend on the thickness of both the GaMnN film and the adjacent GaN:Mg layer and on the presence of a wide band gap barrier at this interface. These results are explained based on the occupancy of the Mn energy band and how the occupancy can be altered due to carrier transfer at the GaMnN∕GaN:Mg interfaces.

Several concepts of integration of the epitaxial rare-earth oxides into the emerging advanced semiconductor on silicon technology are presented. Germanium grows epitaxially on gadolinium oxide despite lattice mismatch of more than 4%. Additionally, polymorphism of some of the rare-earth oxides allows engineering of their crystal structure from hexagonal to cubic and formation of buffer layers that can be used for growth of germanium on a lattice matched oxide layer. Molecular beam epitaxy and metal organic chemical vapor deposition of gallium nitride on the rare-earth oxide buffer layers on silicon is discussed.

Growth of GaN on rare earth oxide (REO) buffers grown on silicon (111) was performed. A novel low temperature buffer layer was developed in order to suppress the decomposition of the REO buffer under hydrogen flow during MOCVD. GaN films, grown by this technique, exhibit smooth surface morphologies. XRD studies reveal the formation of an ErN layer during growth. 10.1149/05804.0455ecst ©The Electrochemical Society ECS Transactions, 58 (4) 455-461 (2013) 455 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-06-10 to IP

The erbium oxide and nitride layers were grown as a buffer for GaN on Si(111). Engineering of the nucleation layer on the oxide plays a crucial role in the quality of the GaN layer. The intermediate erbium nitride layer with lattice constant between that of GaN and Si additionally reduces the semiconductor layer lattice mismatch to the substrate and prevents direct bonding of gallium atoms with the oxygen of the rare‐earth oxide. The crystal structure and surface morphology of epitaxial single crystal gallium nitride layer grown on the buffer improves with the semiconductor layer thickness. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)