Growth of TaC thin films by reactive direct current magnetron sputtering: Composition and structure

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA)

DOI:https://doi.org/10.1116/1.576492· OSTI ID:6485397

Hakansson, G; Petrov, I; Sundgren, J ^[1]

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1. Thin Film Group, Department of Physics, Linkoeping University, S-58183 Linkoeping (Sweden)

Single-phase TaC films were grown by reactive dc magnetron sputtering onto high speed steel substrates kept at 650 {degree}C (0.22 {ital T}{sub {ital m}} ). The films were grown in both Ar/CH{sub 4} and Xe/CH{sub 4} mixtures using target-to-substrate distances, {ital d}{sub ts}, of 6 and 15 cm. For all growth conditions, plasma-probe measurements were carried out. As-deposited films were analyzed using Auger electron spectroscopy (AES), x-ray diffraction (XRD), and transmission electron microscopy (TEM). The C content of the films, as measured with AES, was found to increase linearly with increasing CH{sub 4} partial pressure in all cases. However, both the slope of these curves and the CH{sub 4} pressure needed in order to obtain a certain C content in the films were different depending on both {ital d}{sub ts} and the sputtering gas. These results are explained with arguments based on cracking of the CH{sub 4} molecules into more reactive CH{sub {ital n}} radicals in the plasma and a different gas scattering of these radicals compared to the sputtered Ta atoms. Also, the structure of the deposited films was depending on the sputtering gas and all films grown in Ar/CH{sub 4} showed a considerably higher strain level compared to films grown in Xe/CH{sub 4} discharges. This higher strain level is due to the generation of defects in the films induced by a large flux of backscattered energetic neutral Ar atoms that imping on the growing film. In the Xe case, the energy of the backscattered neutrals is not sufficient to generate defects in the films. The structure of the films was also found to depend on the C content. For over-stoichiometric films, TEM analyses showed that the grain size was only a few nanometers and that there are low density regions surrounding the grains suggesting a precipitation of the excess C.

• OSTI ID: 6485397
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA), Vol. 8:5; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TANTALUM CARBIDES
SPUTTERING
AUGER ELECTRON SPECTROSCOPY
CHEMICAL COMPOSITION
FILMS
MAGNETRONS
STRAINS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
CARBIDES
CARBON COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
MICROSCOPY
MICROWAVE EQUIPMENT
MICROWAVE TUBES
REFRACTORY METAL COMPOUNDS
SCATTERING
SPECTROSCOPY
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication