Abstract
Electron paramagnetic resonance (EPR) measurements have been made of defects in amorphous hydrogenated carbon (a-C:H) thin films. The films were grown on silicon substrates on the earthed electrode of an rf-powered plasma enhanced chemical vapour deposition reactor and were subsequently implanted with a range of doses of boron, carbon or nitrogen ions with energies from 20 keV to 32.5 keV. Two paramagnetic centres are observed, the carbon defect in the film with g = 2.0028(1) and a silicon defect in the substrate with g = 2.0058(6). The volume concentration of the carbon defect increases approximately linearly with dose, from approximately 3 × 1017 cm-3 for unimplanted samples to 2.7 × 1020 cm-3 at the highest implantation of 2 × 1016 B+ ions cm-2. The increase in dose over this range also causes a narrowing of the EPR line (from 0.83 mT to 0.13 mT) and a significant decrease in the spin-lattice relaxation time (from 3 × 10-5 s to 6 × 10-8 s) which approaches the spin-spin relaxation time at the highest dose. The narrowing is attributed to motional averaging produced by either exchange or hopping. We also report the effects of annealing samples implanted with a range of boron doses. The prime novelty of this paper is that it is the first EPR study of defects produced by the implantation of a range of ions into polymer-like amorphous hydrogenated carbon.
| Original language | English |
|---|---|
| Pages (from-to) | 993-997 |
| Number of pages | 5 |
| Journal | Diamond and Related Materials |
| Volume | 10 |
| Issue number | 3-7 |
| DOIs | |
| Publication status | Published - Mar 2001 |
| Externally published | Yes |
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Electron paramagnetic resonance study of ion implantation induced defects in amorphous hydrogenated carbon. / Jones, B. J.; Barklie, R. C.; Khan, R. U A; Carey, J. D.; Silva, S. R P.
In: Diamond and Related Materials, Vol. 10, No. 3-7, 03.2001, p. 993-997.Research output: Contribution to journal › Article
TY - JOUR
T1 - Electron paramagnetic resonance study of ion implantation induced defects in amorphous hydrogenated carbon
AU - Jones, B. J.
AU - Barklie, R. C.
AU - Khan, R. U A
AU - Carey, J. D.
AU - Silva, S. R P
PY - 2001/3
Y1 - 2001/3
N2 - Electron paramagnetic resonance (EPR) measurements have been made of defects in amorphous hydrogenated carbon (a-C:H) thin films. The films were grown on silicon substrates on the earthed electrode of an rf-powered plasma enhanced chemical vapour deposition reactor and were subsequently implanted with a range of doses of boron, carbon or nitrogen ions with energies from 20 keV to 32.5 keV. Two paramagnetic centres are observed, the carbon defect in the film with g = 2.0028(1) and a silicon defect in the substrate with g = 2.0058(6). The volume concentration of the carbon defect increases approximately linearly with dose, from approximately 3 × 1017 cm-3 for unimplanted samples to 2.7 × 1020 cm-3 at the highest implantation of 2 × 1016 B+ ions cm-2. The increase in dose over this range also causes a narrowing of the EPR line (from 0.83 mT to 0.13 mT) and a significant decrease in the spin-lattice relaxation time (from 3 × 10-5 s to 6 × 10-8 s) which approaches the spin-spin relaxation time at the highest dose. The narrowing is attributed to motional averaging produced by either exchange or hopping. We also report the effects of annealing samples implanted with a range of boron doses. The prime novelty of this paper is that it is the first EPR study of defects produced by the implantation of a range of ions into polymer-like amorphous hydrogenated carbon.
AB - Electron paramagnetic resonance (EPR) measurements have been made of defects in amorphous hydrogenated carbon (a-C:H) thin films. The films were grown on silicon substrates on the earthed electrode of an rf-powered plasma enhanced chemical vapour deposition reactor and were subsequently implanted with a range of doses of boron, carbon or nitrogen ions with energies from 20 keV to 32.5 keV. Two paramagnetic centres are observed, the carbon defect in the film with g = 2.0028(1) and a silicon defect in the substrate with g = 2.0058(6). The volume concentration of the carbon defect increases approximately linearly with dose, from approximately 3 × 1017 cm-3 for unimplanted samples to 2.7 × 1020 cm-3 at the highest implantation of 2 × 1016 B+ ions cm-2. The increase in dose over this range also causes a narrowing of the EPR line (from 0.83 mT to 0.13 mT) and a significant decrease in the spin-lattice relaxation time (from 3 × 10-5 s to 6 × 10-8 s) which approaches the spin-spin relaxation time at the highest dose. The narrowing is attributed to motional averaging produced by either exchange or hopping. We also report the effects of annealing samples implanted with a range of boron doses. The prime novelty of this paper is that it is the first EPR study of defects produced by the implantation of a range of ions into polymer-like amorphous hydrogenated carbon.
U2 - 10.1016/S0925-9635(00)00364-2
DO - 10.1016/S0925-9635(00)00364-2
M3 - Article
AN - SCOPUS:0035269984
VL - 10
SP - 993
EP - 997
JO - Diamond and Related Materials
JF - Diamond and Related Materials
SN - 0925-9635
IS - 3-7
ER -