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Effect of thermal treatment on the growth, structure and luminescence of nitride-passivated silicon nanoclusters.

Wilson PR, Roschuk T, Dunn K, Normand EN, Chelomentsev E, Zalloum OH, Wojcik J, Mascher P - Nanoscale Res Lett (2011)

Bottom Line: Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure.The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity.The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4L7, Canada. wilsonpr@mcmaster.ca.

ABSTRACT
Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra.

No MeSH data available.


Related in: MedlinePlus

PL spectra for as-deposited SRSN films grown by (a) PECVD, (b) ECR PECVD, and (c) ICP CVD with their respective excess silicon contents specified in the legend. As excess silicon content increases, emission shifts to lower energies.
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Figure 1: PL spectra for as-deposited SRSN films grown by (a) PECVD, (b) ECR PECVD, and (c) ICP CVD with their respective excess silicon contents specified in the legend. As excess silicon content increases, emission shifts to lower energies.

Mentions: The luminescent properties of the various films were analysed through their room temperature ultraviolet-excited PL spectra. Figure 1 compares the PL spectra from the AD samples from the three systems. Note that the ECR PECVD film with 2% excess silicon content depicted in this figure was grown using a slightly higher substrate heater temperature of 350°C, which may have resulted in higher emission intensity than a film with similar composition deposited at 300°C. Despite the differences in deposition conditions between the systems, similar trends can be observed. Each system produces AD films exhibiting bright PL with emission energies that can be controlled through the full range of the visible and into the near-infrared portion of the electromagnetic spectrum by increasing the excess silicon content in the film. This correlates well with expected quantum confinement effects as Si-ncs increase in size. However, for each system, the emission occurs across a broad range of energies and appears to originate from a combination of quantum confinement effects and defect levels, which have peaks at approximately constant energies independent of the film composition. These defect-related peaks are most prominent in films with low excess silicon content, in which smaller Si-ncs form. As the dimensions of the Si-ncs are reduced, the defect levels become excited and emission through these levels becomes more dominant. The fact that significant PL intensity is observed in the AD films indicates that Si-ncs are formed within SRSN films without the assistance of annealing. This is different from what occurs in silicon-rich silicon oxide (SRSO) films where cluster formation and resulting luminescence occur only after high temperature annealing [14]. The PL intensity of the SRSN films in this study has been qualitatively described as 'bright', which is a rather arbitrary term. Since quantitative measurements of emission intensity have yet to be performed, the term bright is qualified here as PL that is easily visible under typical room lighting conditions.


Effect of thermal treatment on the growth, structure and luminescence of nitride-passivated silicon nanoclusters.

Wilson PR, Roschuk T, Dunn K, Normand EN, Chelomentsev E, Zalloum OH, Wojcik J, Mascher P - Nanoscale Res Lett (2011)

PL spectra for as-deposited SRSN films grown by (a) PECVD, (b) ECR PECVD, and (c) ICP CVD with their respective excess silicon contents specified in the legend. As excess silicon content increases, emission shifts to lower energies.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211220&req=5

Figure 1: PL spectra for as-deposited SRSN films grown by (a) PECVD, (b) ECR PECVD, and (c) ICP CVD with their respective excess silicon contents specified in the legend. As excess silicon content increases, emission shifts to lower energies.
Mentions: The luminescent properties of the various films were analysed through their room temperature ultraviolet-excited PL spectra. Figure 1 compares the PL spectra from the AD samples from the three systems. Note that the ECR PECVD film with 2% excess silicon content depicted in this figure was grown using a slightly higher substrate heater temperature of 350°C, which may have resulted in higher emission intensity than a film with similar composition deposited at 300°C. Despite the differences in deposition conditions between the systems, similar trends can be observed. Each system produces AD films exhibiting bright PL with emission energies that can be controlled through the full range of the visible and into the near-infrared portion of the electromagnetic spectrum by increasing the excess silicon content in the film. This correlates well with expected quantum confinement effects as Si-ncs increase in size. However, for each system, the emission occurs across a broad range of energies and appears to originate from a combination of quantum confinement effects and defect levels, which have peaks at approximately constant energies independent of the film composition. These defect-related peaks are most prominent in films with low excess silicon content, in which smaller Si-ncs form. As the dimensions of the Si-ncs are reduced, the defect levels become excited and emission through these levels becomes more dominant. The fact that significant PL intensity is observed in the AD films indicates that Si-ncs are formed within SRSN films without the assistance of annealing. This is different from what occurs in silicon-rich silicon oxide (SRSO) films where cluster formation and resulting luminescence occur only after high temperature annealing [14]. The PL intensity of the SRSN films in this study has been qualitatively described as 'bright', which is a rather arbitrary term. Since quantitative measurements of emission intensity have yet to be performed, the term bright is qualified here as PL that is easily visible under typical room lighting conditions.

Bottom Line: Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure.The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity.The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4L7, Canada. wilsonpr@mcmaster.ca.

ABSTRACT
Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra.

No MeSH data available.


Related in: MedlinePlus