Tungsten oxide thin films chemically vapor deposited at low pressure by W(CO){sub 6} pyrolysis

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1837453· OSTI ID:465106

Davazoglou, D; Moutsakis, A; Valamontes, V; Psycharis, V ^[1]; Tsamakis, D ^[2]

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1. NCSR Demokritos, Agia Paraskevi Attiki (Greece)
2. National Polytechnic School of Athens (Greece)

Tungsten oxide thin films were grown by chemical vapor deposition at low pressure (0.1 Torr) and at temperatures ranging between 450 and 600 C, in a cold wall horizontal reactor by pyrolysis of W(CO){sub 6} vapors. A small air flow through the reactor induces the growth of remarkably well-textured polycrystalline WO{sub 3} films, oriented with the <010> crystallographic axis perpendicular to the substrate as shown by x-ray diffraction and atomic force microscopy measurements. The films were grown on silicon wafers covered by SiO{sub 2}, Si{sub 3}N{sub 4}, and polycrystalline silicon; the film texture was not influenced by the nature of the substrate. In the absence of oxygen during deposition the x-ray diffraction patterns show peaks corresponding to W{sub 3}O (beta-tungsten) and to body centered cubic tungsten. These films exhibited metallic or insulating properties depending on the deposition temperature, as determined by resistivity measurements within the range 77 to 350 K. The metallic character was enhanced at lower temperatures. After thermal annealing of these films at 1,000 C for 10 s in medium vacuum (2 {times} 10{sup {minus}2} Torr) their character changed to purely metallic. The x-ray diffraction patterns taken after annealing show peaks corresponding to body centered cubic W and WO{sub 2}.

• Sponsoring Organization: USDOE
• OSTI ID: 465106
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 144; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBONYLS
CHEMICAL VAPOR DEPOSITION
ELECTRICAL PROPERTIES
PYROLYSIS
SUBSTRATES
TUNGSTEN COMPOUNDS
TUNGSTEN OXIDES
VAPOR DEPOSITED COATINGS