Cubic HfO{sub 2} doped with Y{sub 2}O{sub 3} epitaxial films on GaAs (001) of enhanced dielectric constant

Journal Article · Mon Apr 09 00:00:00 EDT 2007 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2722226· OSTI ID:20960211

Yang, Z K; Lee, W C; Lee, Y J; Chang, P; Huang, M L; Hong, M; Hsu, C -H; Kwo, J ^[1]

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1. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

Nanometer thick cubic HfO{sub 2} doped with 19 at. % Y{sub 2}O{sub 3} (YDH) epitaxial films were grown on GaAs (001) using molecular beam epitaxy. Structural studies determined the epitaxial orientation relationships between the cubic YDH films and GaAs to be (001){sub GaAs}//(001){sub YDH} and [100]{sub GaAs}//[100]{sub YDH}. The YDH structure is strain relaxed with a lattice constant of 0.5122 nm with a small mosaic spread of 0.023 deg. and a twist angle of 2.9 deg. The YDH/GaAs interface is atomically abrupt without evidence of reacted interfacial layers. From C-V and I-V measurements a 7.7 nm thick YDH film has an enhanced dielectric constant {kappa}{approx}32, an equivalent oxide thickness of {approx}0.94 nm, an interfacial state density D{sub it}{approx}7x10{sup 12} cm{sup -2} eV{sup -1}, and a low leakage current density of 6x10{sup -5} A/cm{sup 2} at 1 V gate bias.

• OSTI ID: 20960211
• Journal Information: Applied Physics Letters, Vol. 90, Issue 15; Other Information: DOI: 10.1063/1.2722226; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
CUBIC LATTICES
DIELECTRIC MATERIALS
DOPED MATERIALS
GALLIUM ARSENIDES
GRAIN ORIENTATION
HAFNIUM OXIDES
INTERFACES
LATTICE PARAMETERS
LAYERS
LEAKAGE CURRENT
MOLECULAR BEAM EPITAXY
PERMITTIVITY
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
YTTRIUM OXIDES