Growth of scandium magnesium oxide on GaN

A. H. Onstine, A. Herrero, B. P. Gila, Ji Hyun Kim, R. Mehandru, C. R. Abernathy, F. Ren, S. J. Pearton

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Sc 2O 3 and MgO have been previously shown to be promising gate dielectrics for III-nitride devices. However, even though the films are initially epitaxial, they possess large numbers of defects due to the large mismatch with GaN. Thus further improvements in interface electrical characteristics will require a reduction in the interfacial mismatch between the oxides and the GaN. This paper discusses the feasibility of reducing the Sc 2O 3 lattice constant via the introduction of Mg and in particular investigates the relationship between growth parameters and microstructure for the resulting ScMgO alloy. Increasing the magnesium cell temperature was found to increase the growth rate but have little effect on surface roughness. Higher Mg cell temperatures also produced evidence in x-ray diffraction (XRD) of a second phase of MgScO which has the rock salt crystal structure and contains ∼2%Sc. Increasing the substrate temperature from 100°C to 300°C was found to have little effect on the growth rate and dramatically increased surface roughness. However higher substrate temperature combined with a lower Mg cell temperature produced a more uniform oxygen profile as determined by depth profiling Auger Electron Spectroscopy (AES). From AES and XRD, the solid solubility limit for Sc xMg 1-xO with the Bixbyite structure was reached at about X Mg =0.28.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsC.R. Abernathy, E.P. Gusev, D. Schlom, S. Stemmer
Pages397-401
Number of pages5
Volume786
Publication statusPublished - 2003
Externally publishedYes
EventFundamentals of Novel Oxide/Semiconductor Interfaces Symposium - Boston, MA., United States
Duration: 2003 Dec 12003 Dec 4

Other

OtherFundamentals of Novel Oxide/Semiconductor Interfaces Symposium
CountryUnited States
CityBoston, MA.
Period03/12/103/12/4

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Onstine, A. H., Herrero, A., Gila, B. P., Kim, J. H., Mehandru, R., Abernathy, C. R., ... Pearton, S. J. (2003). Growth of scandium magnesium oxide on GaN. In C. R. Abernathy, E. P. Gusev, D. Schlom, & S. Stemmer (Eds.), Materials Research Society Symposium - Proceedings (Vol. 786, pp. 397-401)