University of Virginia MRSEC

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University of Virginia MRSEC
Nanoscale Control of GeSi/Si Quantum Dot
Nucleation by In-Situ FIB Surface Modification A.
Portavoce, M. Kammler, R. Hull, UVa
F. Ross, M. Reuter, R.
Tromp, IBM
Typical Ga Dose 1014 cm-2
In-Situ TEM Images Left FIB implanted Right
Ge QD Nucleation
QCA Bistable Logic
QCA Adder Circuit
Ex-Situ AFM Image
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• Intrinsic Merit
• Fundamental advances in understanding epitaxial
  nucleation on locally modified surfaces
• Detailed understanding of FIB-guided nucleation
  local strain plus surface nano-topography
• Scaleable to large arrays FIB write speed c.
  104 features per second
• Extraploation to new systems e.g. epitaxial
  metallic oxide dots (J. Groves, Y. Du, UVa)
• Broader Impact
• Possible application to Quantum Cellular Automata
  and other Nanoelectronic Architectures (with G.
  Snider, X. Luo, Notre Dame)
• Close collaboration between leading industrial
  research lab (IBM Yorktown Heights) and UVa MRSEC
  
• Integration of Research and Education new course
  at UVa MSE 791, Nanoscale Processes at Surfaces
• Next Steps
• Smaller QD spacings (reduce instrumental
  vibration, smaller ion spot sizes)
• Developing mass-selecting FIB column Si, Ge,
  As. B beams from mass separated alloy sources
• In-situ LEEM, STM studies