Single-Electron Capacitance Spectroscopy of Individual Dopants in Silicon

• Published in: Nano letters Vol. 11; no. 12; pp. 5208 - 5212
• Main Authors: Gasseller, M, DeNinno, M, Loo, R, Harrison, J. F, Caymax, M, Rogge, S, Tessmer, S. H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14-12-2011
• Subjects: Applied sciences; Atomic beam spectroscopy; Boron; Dopants; Electronics; Exact sciences and technology; Molecular electronics, nanoelectronics; Nanostructure; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Spectroscopy; Transport; single-electron tunneling; capacitance; scanning probe microscopy; dopant molecules; Subsurface dopants; Boron; Semiconductor device; Resonance; Silicon; Single electron device; Spatial resolution
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl2025163

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.