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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 Siex = 3% films annealed at 800°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time.
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Figure 12: PL spectra for Siex = 3% films annealed at 800°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time.

Mentions: The PL spectra for the film with 3% excess silicon content annealed at 800°C exhibited the same features as those of the 600°C annealed films as can be seen in Figure 12. As in Figure 8, the annealed spectra have been renormalized so that they have the same peak intensity while the AD spectrum has been renormalized so that it maintained its relative intensity with the 2 s anneal. In this case, the AD peak appears smaller than in Figure 8 due to the relatively large PL intensity of the 2-s-annealed film at 800°C compared with its 600°C counterpart. At 800°C, there was still a main peak that red-shifted with longer annealing times and a high energy shoulder that was less pronounced than at the lower temperature and nearly disappeared at the longer annealing times. The peak PL energy is plotted in Figure 9a, which illustrates that the initial abrupt energy shift upon annealing is much larger than for the 600°C anneals and even exceeds the shift observed for all but the longest anneals measured at this temperature. However, for longer anneals, the peak PL energy shifted at a much slower rate than at 600°C. This was likely due to the reduction of excess silicon in the film within close proximity of a Si-nc that has not already been incorporated into the structure and the larger number of additional Si atoms required for continuing to increase the diameter of a Si-nc as it grows. The total power density profile shown in Figure 9b shows some interesting differences to those observed after the 600°C anneal. At 800°C, there was a very large increase in the emission intensity after just 2 s of annealing, which also far exceeded the total power densities measured for any of the 600°C anneals. While an overall increase in total power density was observed at 600°C over the range of annealing times studied, an intensity peak was observed between 6 and 30 s at the higher temperature, followed by a steady decline, eventually dropping below the 600°C value at the 900 s mark. This decline may indicate Ostwald ripening or structural changes in the silicon nitride host matrix.


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 Siex = 3% films annealed at 800°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 12: PL spectra for Siex = 3% films annealed at 800°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time.
Mentions: The PL spectra for the film with 3% excess silicon content annealed at 800°C exhibited the same features as those of the 600°C annealed films as can be seen in Figure 12. As in Figure 8, the annealed spectra have been renormalized so that they have the same peak intensity while the AD spectrum has been renormalized so that it maintained its relative intensity with the 2 s anneal. In this case, the AD peak appears smaller than in Figure 8 due to the relatively large PL intensity of the 2-s-annealed film at 800°C compared with its 600°C counterpart. At 800°C, there was still a main peak that red-shifted with longer annealing times and a high energy shoulder that was less pronounced than at the lower temperature and nearly disappeared at the longer annealing times. The peak PL energy is plotted in Figure 9a, which illustrates that the initial abrupt energy shift upon annealing is much larger than for the 600°C anneals and even exceeds the shift observed for all but the longest anneals measured at this temperature. However, for longer anneals, the peak PL energy shifted at a much slower rate than at 600°C. This was likely due to the reduction of excess silicon in the film within close proximity of a Si-nc that has not already been incorporated into the structure and the larger number of additional Si atoms required for continuing to increase the diameter of a Si-nc as it grows. The total power density profile shown in Figure 9b shows some interesting differences to those observed after the 600°C anneal. At 800°C, there was a very large increase in the emission intensity after just 2 s of annealing, which also far exceeded the total power densities measured for any of the 600°C anneals. While an overall increase in total power density was observed at 600°C over the range of annealing times studied, an intensity peak was observed between 6 and 30 s at the higher temperature, followed by a steady decline, eventually dropping below the 600°C value at the 900 s mark. This decline may indicate Ostwald ripening or structural changes in the silicon nitride host matrix.

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