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The effect of silicon doping and thermal annealing on the electrical and structural properties of hydrogenated amorphous carbon thin films

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Okpalugo, TIT, Maguire, PD, Ogwu, AA and McLaughlin, JAD (2004) The effect of silicon doping and thermal annealing on the electrical and structural properties of hydrogenated amorphous carbon thin films. DIAMOND AND RELATED MATERIALS, 13 (4-8). pp. 1549-1552. [Journal article]

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URL: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TWV-4BBVY5K-9-F&_cdi=5572&_user=126978&_orig=search&_coverDate=08%2F31%2F2004&_sk=999869995&view=c&wchp=dGLbVlz-zSkWb&md5=31aada086279c2516ca7c8c31f971ee6&ie=/sdarticle.pdf

DOI: 10.1016/j.daimond.2003.11.032

Abstract

Silicon addition to a-C:H (hydrogenated amorphous carbon) thin films offers many advantages and a full understanding of the electrical properties of a-C:H:Si thin films is necessary for applications like biomedical implants and biosensor devices. The thin films were deposited with 13.56 MHz RF-PECVD (plasma enhanced chemical vapour deposition) using acetylene, argon and tetramethylsilane (TMS) vapour on p-type and n-type Si (100) wafers, and some of the films were further modified by thermal annealing. Silicon incorporation into a-C:H improves the thermal stability against graphitisation but decreases the film resistivity and breakdown strength. The breakdown strength variation is likely to be determined by inclusion of conductive clusters but the source of these clusters is unclear, since Raman indicates an increase in sp(3) content. The contact potentialdifference (CPD) of a-C:H thin films decreased by (approx. 0.21-0.43 eV) with increasing annealing temperatures, due to reduction in bandgap towards graphite, and increasing amounts of silicon, suggesting a more p-type structure due to higher trap densities, although change in bandgap or surface charge may also play a role. (C) 2003 Elsevier B.V. All rights reserved.

Item Type:Journal article
Keywords:DLC; silicon doping; work function; electrical characteristics
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:217
Deposited By:Mrs Ann Blair
Deposited On:01 Sep 2009 14:53
Last Modified:21 Feb 2014 15:12

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