Plasma enhanced chemical vapour deposition of tungsten and tungsten silicide thin films

• Published in: Applied surface science Vol. 73; pp. 58 - 63
• Main Authors: McClatchie, S., Thomas, H., Morgan, D.V.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.1993; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Structure and morphology; thickness; Surface double layers, schottky barriers, and work functions; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Grain size; Plasma; Inorganic compounds; Transition element compounds; Experimental study; Fabrication property relation; CVD; CV characteristic; Thin films; Transition elements; Tungsten; Tungsten silicides; Schottky barrier diodes; Microstructure; IV characteristic
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/0169-4332(93)90146-3

The plasma enhanced chemical vapour deposition of tungsten and tungsten silicide thin films onto GaAs has been investigated over a range of deposition conditions using a modified parallel plate radial flow reactor. The tungsten films deposited from WF 6 and H 2 were typically smooth and adherent with as-deposited resistivities in the range 20–100 μΩ·cm and a grain size in the range 200–2000 Å. Schottky properties for diodes fabricated from the as-deposited layers showed current-voltage characteristics governed by thermionic emission with ideality factors ( n) as low as 1.04. WSi x films deposited from WF 6 and SiH 4 were typically smooth and adherent with a grain size <200 Å. Schottky diodes fabricated from these layers also exhibited good Schottky properties. It was possible to deposit films ranging from nearly pure tungsten to nearly pure silicon using this technique by varying the WF 6:SiH 4 gas flow ratio.