University of Virginia MRSEC

1. UHV-CVD-TEM-FIB (IBM) 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

2. 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