Praseodymium silicate formed by postdeposition high-temperature annealing

Journal Article · Mon Nov 29 04:00:00 EST 2004 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1828584· OSTI ID:20634481

Sakai, Akira; Sakashita, Shinsuke; Sakashita, Mitsuo; Yasuda, Yukio; Zaima, Shigeaki; Miyazaki, Seiichi ^[1]

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1. Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

Praseodymium silicate (Pr silicate) has been synthesized by molecular-beam deposition of Pr{sub 2}O{sub 3} layers on Si(111) substrates and subsequent high-temperature postdeposition annealing at 1000 deg. C. This thermal treatment drastically changes the film texture from the crystalline Pr{sub 2}O{sub 3} epitaxially grown on Si, into Pr silicate with completely amorphized structures, resulting from intermixing of Si from the substrate. It was found that the electrical characteristics of Pr silicate were critically dependent on the quality of the as-deposited Pr{sub 2}O{sub 3} films. A typical dielectric constant and a leakage current density of Pr silicate grown under an optimal condition were, respectively, 19.7 and 3x10{sup -9} A cm{sup -2} at +1 V relative to the flatband voltage for an equivalent oxide thickness of 1.9 nm. Using x-ray photoelectron spectroscopy, a valence-band offset at the Pr-silicate/Si(111) interface of 2.75 eV and a band gap of 6.50 eV were obtained. The large band gap and the highly symmetric band alignment account for the observed low leakage current density.

• OSTI ID: 20634481
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 22 Vol. 85; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
ANNEALING
CURRENT DENSITY
DEPOSITION
DIELECTRIC MATERIALS
ELECTRIC POTENTIAL
ENERGY GAP
EV RANGE 01-10
LAYERS
LEAKAGE CURRENT
MOLECULAR BEAM EPITAXY
PERMITTIVITY
PRASEODYMIUM SILICATES
SILICON
SUBSTRATES
TEMPERATURE RANGE 1000-4000 K
TEXTURE
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY