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7/31/2019 Silicon Quantum Dots
1/21
Silicon Quantum Dots: Grownby Ion Implantation and
annealing
By
Mary Coan
7/31/2019 Silicon Quantum Dots
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Outline
History of Silicon quantum dots How they were made
Properties of Silicon Quantum Dots grown
by ion implantation and annealing Advantages/Disadvantages
Different methods to grow Silicon
Quantum Dots Which method is the best?
Summary
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History of Si QDs
1960s: First quantum size effects were
seen in semiconductor nanocrystals
1970s: Louis Brus was working in Bell
Labs researching colloidal synthesizes
1980s: First semiconductor quantum dots
were grown
1990: First visible-photoluminescence
seen from Si QDs
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History of Si QDs
1993: Silicon optoelectronic integratedcircuit is suggested
1993 to present: Si Quantum dots have
been extensively researched Different fabrication methods
microwave plasma decomposition of SiH4
laser breakdown of SiH4
plasma-enhanced chemical vapor deposition
high frequency discharge
high dose ion implantation
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Formation of Si QDs: Ion
implantation and annealing
T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).
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Properties of Si QDs
Photoluminescence
Peak energy and intensity
Size ranges from 1 nm to over 10 nm indiameter
Size distribution within host material
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Photoluminescence
C.W. White, J.D. Budai, S.P. Withrow, J.G. Zhu and S.J. Pennycock, IEEEConference Proceeding 824 (1996).
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Photoluminescence
T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).
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Photoluminescence
T.S. Iwayama, T. Hama, D.E. Hole, I.W.Boyd, Vacuum 81, 179 (2006).
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Suggested Mechanisms
T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Solid-State Electronics 45, 1487 (2001).
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Suggested Mechanisms
R. Krishnan, UR, (2005).
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Range of Sizes
Longer anneals = Larger Si QDs
Ostwald Ripening
T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).
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Size distribution within Host Material
M.L. Brongersma, A. Polman, K.S. Min, H.A.Atwater, J. Appl. Phys. 86, 759 (1999).
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Defects within Host
C. J. Nicklaw, M. P. Pagey, S. T. Pantelides, D. M. Fleetwood, R. D. Schrimpf, K. F.
Galloway, J. E. Wittig, B. M. Howard, E. Taw, W. H. McNeil, J. F. Conley, Jr., IEEE Trans.Nucl. Science 47, 2269 (2000).
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Defects within Host
C. J. Nicklaw, M. P. Pagey, S. T. Pantelides, D. M. Fleetwood, R. D. Schrimpf, K. F.
Galloway, J. E. Wittig, B. M. Howard, E. Taw, W. H. McNeil, J. F. Conley, Jr., IEEE Trans.Nucl. Science 47, 2269 (2000).
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Defects within Host
C. J. Nicklaw, M. P. Pagey, S. T. Pantelides, D. M. Fleetwood, R. D. Schrimpf, K. F.
Galloway, J. E. Wittig, B. M. Howard, E. Taw, W. H. McNeil, J. F. Conley, Jr., IEEE Trans.Nucl. Science 47, 2269 (2000).
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Advantages/Disadvantages
Advantages:
Ease of integration into silicon based
microelectronics (Dots and Process)
Ability to control the PL intensity and peak
energy
Disadvantages:
Large size distribution within host material
Defects within host material
Surface damage (QDs)
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Other Fabrication Techniques
Microwave Plasma Decomposition of
Silane Gas
Laser breakdown of Silane Gas
Plasma Enhanced Chemical Vapor
Deposition
High Frequency Spark Discharge Colloidal
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Which Method is Best?
It depends on what you want to use the
Silicon QDs for.
If you want to make an optoelectical
integrated circuit:
Plasma Enhanced CVD
Ion Implantation
If you want some cool flourishing Si QDs:
Colloidal
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Summary
Properties of Si QDs were discussed
PL dependent on: Anneal time, temperature and process
Ion dose Defects caused by Ion Implantation
Quantum dot surface\host material Causing lower luminescence intensity
A Large size distribution throughout the Host
In the past this was a good technique nowit is outdated by PCVD
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Questions ??