Investigation into the mechanism of ductility of thin amorphous Ta/sub 2/O/sub 5/ films

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5954693

Rizkalla, H L

Thin films (300-800 A) of tantalum metal were successfully sputter deposited on uniformly deformable fluoropolymer and polyimide substrates in stress free form. The crystal structure of the deposited Ta films depends mainly on the sputtering parameters. These films were later anodized into amorphous Ta/sub 2/O/sub 5/ which is a non-porous (barrier-type) oxide with excellent corrosion resistant properties. Ta/sub 2/O/sub 5/ films were also obtained by direct electron beam evaporation (EBE) of Ta/sub 2/O/sub 5/ on different metallic and polymeric substrates, XPS and AES studies were carried out on Ta, anodic and EBE Ta/sub 2/O/sub 5/ films to determine the chemical composition and oxidation states of elements. Thin Ta and Ta/sub 2/O/sub 5/ films on fluoropolymer substrates contained fluorine as an impurity while similar films on polyimide contained no fluorine and, in general, fewer impurities. EBE Ta/sub 2/O/sub 5/ films gave a stoichiometric O/Ta ratio all through the film thickness while the presence of suboxides and adsorbed OH group in anodic films was suggested by XPS and confirmed by FTIR absorption characteristics. Both thin Ta film and the corresponding anodic oxides, when deformed at room temperature to 10% strain, exhibied the ductile behavior of metals where slip bands were observed in the electron microscope. On the other hand, EBE Ta/sub 2/O/sub 5/ films failed in a brittle manner when deformed beyond 1% tensile strain at room temperature.

• Research Organization: Minnesota Univ., Minneapolis (USA)
• OSTI ID: 5954693
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TANTALUM
DEPOSITION
TANTALUM OXIDES
DUCTILITY
THIN FILMS
DEFORMATION
FAILURES
SPUTTERING
CHALCOGENIDES
ELEMENTS
FILMS
MECHANICAL PROPERTIES
METALS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
TANTALUM COMPOUNDS
TENSILE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties