Single-Electron Capacitance Spectroscopy of Individual Dopants in Silicon

Abstract

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.

17 pages (main text is 5 pages), 3 figures and 4 supplementary figures

References in corpus (4)

• Charge qubits in semiconductor quantum computer architectures: Tunnel coupling and decoherence
• Electric field driven donor-based charge qubits in semiconductors
• Scanning-probe spectroscopy of semiconductor donor molecules
• Direct observation by resonant tunneling of the B^+ level in a delta-doped silicon barrier