Thermoelectric power, Hall coefficient, and structure properties of Ta thin films rf sputtered in Ar--N/sub 2/--O/sub 2/

Journal Article · Sat Jan 01 04:00:00 EST 1977 · J. Vac. Sci. Technol.; (United States)

DOI:https://doi.org/10.1116/1.569114· OSTI ID:7125137

Perinati, A; Piacentini, G F

The electrical properties of 1000-A-thick tantalum films rf sputtered in Ar--N/sub 2/--O/sub 2/ mixtures have been studied. The properties of these films can be related to film structure and composition. For nitrogen-doped films, as shown by AES analysis, thermoelectric power (TEP) may be related to the nitrogen content in the range of values between 10 and 40 at. %; at higher nitrogen contents the Hall coefficient may be more usefully used; in any case TEP and Hall coefficient measurements give complementary informations on transport properties and can be used to evaluate the carrier contribution. The ..beta..-tantalum phase observed at zero reactive-gas flow rate also remains when the oxygen flow rate is increased until the transition to Ta/sub 2/O/sub 5/ is observed. Doubly ionized oxygen vacancies for oxygen-doped films affect the transport properties, thereby giving a small dependence of the electrical parameters on the oxygen content. The AES analysis results for N/sub 2/+O/sub 2/ doped films show that, when oxygen is admitted to a system in which Ta is being sputtered in Ar--N/sub 2/ discharge, the nitrogen content in the film initially increases upon increase of the oxygen flow rate. These data relate well with the observed behavior of the electrical parameters even though the dependence on the reactive-gas flow rate sum is not verified by the Hall coefficient, meaning that also at low oxygen flow rates, small amounts of oxygen reach the Ta film.

• Research Organization: Telettra S.p.A., 20059 Vimercate, Italy
• OSTI ID: 7125137
• Journal Information: J. Vac. Sci. Technol.; (United States), Journal Name: J. Vac. Sci. Technol.; (United States) Vol. 14:1; ISSN JVSTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
CHALCOGENIDES
CRYOGENIC FLUIDS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
FLUIDS
HALL EFFECT
METALS
NITROGEN
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METALS
SPUTTERING
TANTALUM
TANTALUM COMPOUNDS
TANTALUM OXIDES
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS