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IJPAP Vol.46 [2008] >
IJPAP Vol.46(11) [November 2008] >
| Title: | Effect of hydrogen and nitrogen incorporation on the properties of tetrahedral amorphous carbon films grown using S bend filtered cathodic vacuum arc process |
| Authors: | Panwar, O S Khan, Mohd Alim Bhagavanarayana, G Dixit, P N Kumar, Sushil Rauthan, C M S |
| Keywords: | Conductivity Activation energy Residual stress ta-C ta-C: H ta-C: N FCVA |
| Issue Date: | Nov-2008 |
| Publisher: | CSIR |
| Abstract: | The electrical and mechanical properties of as- grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using S bend filtered cathodic vacuum arc process have been reported. First, the effect of varying negative substrate bias on the dark conductivity (σ D), activation energy (ΔE₁) and residual stress of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure on the properties of ta-C: H and ta-C: N films deposited at a high negative substrate bias of -300V are reported. The value of σ D is minimum at 10⁻⁴ ohm ⁻¹cm⁻¹ in as- grown ta-C films deposited at -150V substrate bias whereas the value of ΔE₁ is maximum at 0.22 eV and residual stress is maximum at 0.71 GPa in as- grown ta-C films deposited at -200 V applied substrate bias and it is found to depend on the substrate bias. Hydrogen incorporation in ta-C films decreases the value of σ D to 1.0×10⁻⁹ohm ⁻¹cm⁻¹, increases the values of ΔE₁ to 0.45 eV continuously with the increase of hydrogen partial pressure up to 1.4×10⁻³ mbar whereas nitrogen incorporation in ta-C films increases the value of σ D to 10⁻¹ ohm⁻¹cm⁻¹ and decreases the value of ΔE₁ to 0.07 eV continuously with the increase of nitrogen content up to 16.3 at. %. Low amount of hydrogen incorporation in ta-C films up to 7.4×10⁻⁵mbar hydrogen partial pressure reduces the value of residual stress and larger amount of hydrogen incorporation beyond this pressure increases the value of residual stress whereas nitrogen incorporation in ta-C films reduces the values of residual stress. The effect of hydrogen on ta-C is to give a modest gain in semi-conducting properties by passivating some defect states whereas the effect of nitrogen gives n-type doping effect in ta-C films. |
| Page(s): | 797-805 |
| ISSN: | 0019-5596 |
| Source: | IJPAP Vol.46(11) [November 2008]
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