CeO{sub 2} epitaxial dielectric film on Si substrate by laser ablation technique

Conference · Thu Jun 01 04:00:00 EDT 1995

OSTI ID:55381

Tye, L; Chikyow, T; El-Masry, N A; Bedair, S M ^[1]

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1. North Carolina State Univ., Raleigh, NC (United States)

Thin films of cerium oxide (CeO{sub 2}) were epitaxially grown on silicon(111) substrates by laser ablation under ultra-high vacuum (UHV) conditions. The laser used as an ArF excimer type (193nm), irradiating a pressed and sintered CeO{sub 2} target (99.9%). Deposition occurred at a UHV condition of {approximately}10{sup {minus}8} torr with substrate temperatures between 500 and 800 C. During growth, both the Si substrate and the CeO{sub 2} target were rotated. The deposition rate was in the range of .2 to 5 nm per minute. Investigation by in situ reflection high-energy electron diffraction (RHEED), ex situ transmission electron microscopy (TEM), and x-ray diffraction revealed that single crystal films can be achieved under certain growth conditions on Si(111). Analysis of high resolution cross-sectional TEM data shows that CeO{sub 2}(111) grows epitaxially on Si(111), but an amorphous layer forms at the interface. This is due to a reaction that occurs between the CeO{sub 2} and the Si substrate during growth. The amorphous region has an undesirable effect on the electrical properties of the CeO{sub 2} films as seen by capacitance-voltage measurements. However, by post annealing the films in oxygen, the interface structure can be controlled and the C-V characteristics of the film are improved.

• OSTI ID: 55381
• Report Number(s): CONF-9310328--; ISBN 1-56676-232-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
ANNEALING
CERIUM OXIDES
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
EPITAXY
INTERFACES
MONOCRYSTALS
SILICON
SILICON OXIDES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION