Atomic-layer doping of SiGe heterostructures for atomic-precision donor devices

Abstract

As a first step to porting scanning tunneling microscopy methods of atomic-precision fabrication to a strained-Si/SiGe platform, we demonstrate post-growth P atomic-layer doping of SiGe heterostructures. To preserve the substrate structure and elastic state, we use a T $\le 800^{\circ }$C process to prepare clean Si${}_{0.86}$Ge${}_{0.14}$ surfaces suitable for atomic-precision fabrication. P-saturated atomic-layer doping is incorporated and capped with epitaxial Si under a thermal budget compatible with atomic-precision fabrication. Hall measurements at T$=0.3$ K show that the doped heterostructure has R${}_{\square }=570\pm 30$ $\Omega$, yielding an electron density $n_e=2.1\pm 0.1\times 10^{14}$cm${}^{-2}$ and mobility ${\mu }_e=52\pm 3$ cm${}^2$ V${}^{-1}$ s${}^{-1}$, similar to saturated atomic-layer doping in pure Si and Ge. The magnitude of ${\mu }_e$ and the complete absence of Shubnikov-de Haas oscillations in magnetotransport measurements indicate that electrons are overwhelmingly localized in the donor layer, and not within a nearby buried Si well. This conclusion is supported by self-consistent Schrödinger-Poisson calculations that predict electron occupation primarily in the donor layer.

arXiv comment7 pages, 6 figures, to be submitted to Physical Review Materials. This work has been supported by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy (DOE). This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science

References in corpus (20)

• Silicon Quantum Electronics
• Electron Spin Resonance Transistors for Quantum Computing in Silicon-Germanium Heterostructures
• Exchange in silicon-based quantum computer architecture
• Spin transport and quasi 2D architectures for donor-based quantum computing
• Practical design and simulation of silicon-based quantum dot qubits
• Design and proof of concept for silicon-based quantum dot quantum bits
• A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots
• Encapsulation of phosphorus dopants in silicon for the fabrication of a quantum computer
• Multivalley effective mass theory simulation of donors in silicon
• Investigation of Mobility Limiting Mechanisms in Undoped Si/SiGe Heterostructures
• Ultra-dense phosphorus in germanium delta-doped layers
• Annealing shallow Si/SiO${}_2$ interface traps in electron-beam irradiated high-mobility metal-oxide-silicon transistors
• Two-dimensional metal-insulator transition and in-plane magnetoresistance in a high mobility strained Si quantum well
• Effective mass theory of monolayer δ-doping in the high-density limit
• QCAD Simulation and Optimization of Semiconductor Quantum Dots
• Electronic transport in two dimensional Si:P $\delta$-doped layers
• Weak Localization Thickness Measurements of Si:P Delta-Layers
• All-optical lithography process for contacting atomically-precise devices
• Simulation of Si:P spin-based quantum computer architecture
• Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy

Cited by in corpus (3)

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• A reduced-temperature process for preparing atomically clean Si(100) and SiGe(100) surfaces with vapor HF