Atmospheric pressure chemical vapor deposition of doped zinc oxide thin films and their electrical and optical properties

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:6960505

Hu, J

Zinc oxide thin films have been deposited on various substrates in an atmospheric pressure chemical vapor deposition system. THe film thicknesses and refractive indices were determined with an ellipsometer or by prism coupler. The structure properties of the films were examined by X-ray diffraction and scanning electron microscopy. the film compositions were determined by electron microprobe analysis and Rutherford backscattering and forward recoil spectrometry. Highly transparent and conductive zinc oxide films were produced by doping with foreign atoms such as the Group VII element fluorine and the Group III elements boron, aluminum and gallium. The electrical properties of the doped films were characterized by resistance and Hall coefficient measurements. The optical properties were obtained from UV-Visible-IR reflectance and transmittance measurements. The crystallite size and orientation were found to depend on the deposition temperature and the oxidant and dopant used. The fluorine and aluminum concentrations in the films were generally below 1.5 at.%. The gallium concentration in the film increases almost linearly with the triethyl gallium concentration in the gas phase, up to a gallium concentration of 10 at %. All of the doped films have similar high conductivities. Fluorine doped films have lower electron densities and higher mobilities than to the films doped with the Group III elements. All of the dopands are n-type and increase the free electron density. Zinc oxide films doped with fluorine are more transparent to visible and near infrared light than films doped with the Group III elements. A resistor network model was used to model the electrical and optical properties of zinc oxide films. The most important scattering mechanisms are ionized impurity and grain boundary scattering. The dispersion of the high frequency dielectric constant in the ultraviolet is modeled by a damped Lorentz oscillator.

• Research Organization: Harvard Univ., Cambridge, MA (United States)
• OSTI ID: 6960505
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DOPED MATERIALS
ELECTRICAL PROPERTIES
OPTICAL PROPERTIES
THIN FILMS
ZINC OXIDES
CHEMICAL VAPOR DEPOSITION
ELECTRIC CONDUCTIVITY
MATHEMATICAL MODELS
CHALCOGENIDES
CHEMICAL COATING
DEPOSITION
FILMS
MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SURFACE COATING
ZINC COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
360204 - Ceramics
Cermets
& Refractories- Physical Properties