Single-electron capacitance spectroscopy of individual dopants in silicon.
Motivated by recent transport experiments and proposed atomic-scale semiconductor devices, we present measurements that extend the reach of scanned-probe methods to discern the properties of individual dopants tens of nanometers below the surface of a silicon sample. Using a capacitance-based approach, we have both spatially resolved individual subsurface boron acceptors and detected spectroscopically single holes entering and leaving these minute systems of atoms. A resonance identified as the B+ state is shown to shift in energy from acceptor to acceptor. We examine this behavior with respect to nearest-neighbor distances. By directly measuring the quantum levels and testing the effect of dopant-dopant interactions, this method represents a valuable tool for the development of future atomic-scale semiconductor devices.
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, United States.
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M
Gasseller
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M
DeNinno
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R
Loo
J F
JF
Harrison
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M
Caymax
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S
Rogge
S H
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Tessmer