1. Silicon Quantum Dots: Grown by Ion Implantation and annealing By Mary Coan

2. 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

3. History of Si QDs 1960’s: First quantum size effects were seen in semiconductor nanocrystals 1970’s: Louis Brus was working in Bell Labs researching colloidal synthesizes 1980’s: First semiconductor quantum dots were grown 1990: First visible-photoluminescence seen from Si QDs

4. History of Si QDs 1993: Silicon optoelectronic integrated circuit 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

5. Formation of Si QDs: Ion implantation and annealing T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).

6. Properties of Si QDs Photoluminescence –Peak energy and intensity Size ranges from 1 nm to over 10 nm in diameter Size distribution within host material

7. Photoluminescence C.W. White, J.D. Budai, S.P. Withrow, J.G. Zhu and S.J. Pennycock, IEEE Conference Proceeding 824 (1996).

8. Photoluminescence T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).

9. Photoluminescence T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Vacuum 81, 179 (2006).

10. Suggested Mechanisms T.S. Iwayama, T. Hama, D.E. Hole, I.W. Boyd, Solid-State Electronics 45, 1487 (2001).

11. Suggested Mechanisms R. Krishnan, UR, (2005).

12. 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).

13. Size distribution within Host Material M.L. Brongersma, A. Polman, K.S. Min, H.A. Atwater, “J. Appl. Phys. 86, 759 (1999).

14. 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).

15. 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).

16. 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).

17. 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)

18. Other Fabrication Techniques Microwave Plasma Decomposition of Silane Gas Laser breakdown of Silane Gas Plasma Enhanced Chemical Vapor Deposition High Frequency Spark Discharge Colloidal

19. 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

20. 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 now it is outdated by PCVD

21. Questions ??