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Ramanandan SP, Reñé Sapera J, Morelle A, Martí-Sánchez S, Rudra A, Arbiol J, Dubrovskii VG, Fontcuberta I Morral A. Control of Ge island coalescence for the formation of nanowires on silicon. Nanoscale Horiz 2024; 9:555-565. [PMID: 38353654 PMCID: PMC10962639 DOI: 10.1039/d3nh00573a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/05/2024] [Indexed: 03/26/2024]
Abstract
Germanium nanowires could be the building blocks of hole-spin qubit quantum computers. Selective area epitaxy enables the direct integration of Ge nanowires on a silicon chip while controlling the device design, density, and scalability. For this to become a reality, it is essential to understand and control the initial stages of the epitaxy process. In this work, we highlight the importance of surface treatment in the reactor prior to growth to achieve high crystal quality and connected Ge nanowire structures. In particular, we demonstrate that exposure to AsH3 during the high-temperature treatment enhances lateral growth of initial Ge islands and promotes faster formation of continuous Ge nanowires in trenches. The Kolmogorov-Johnson-Mehl-Avrami crystallization model supports our explanation of Ge coalescence. These results provide critical insight into the selective epitaxy of horizontal Ge nanowires on lattice-mismatched Si substrates, which can be translated to other material systems.
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Affiliation(s)
- Santhanu Panikar Ramanandan
- Laboratory of Semiconductor Materials, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland.
| | - Joel Reñé Sapera
- Laboratory of Semiconductor Materials, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland.
| | - Alban Morelle
- Solid State Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Sara Martí-Sánchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, Catalonia, Spain
| | - Alok Rudra
- Laboratory of Semiconductor Materials, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland.
- Institute of Physics, Faculty of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, Catalonia, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Catalonia, Spain
| | - Vladimir G Dubrovskii
- Faculty of Physics, St. Petersburg State University, Universitetskaya Embankment 13B, 199034 St. Petersburg, Russia
| | - Anna Fontcuberta I Morral
- Laboratory of Semiconductor Materials, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland.
- Institute of Physics, Faculty of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland
- Center for Quantum Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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Žaper L, Rickhaus P, Wyss M, Gross B, Wagner K, Poggio M, Braakman F. Scanning Nitrogen-Vacancy Magnetometry of Focused-Electron-Beam-Deposited Cobalt Nanomagnets. ACS Appl Nano Mater 2024; 7:3854-3860. [PMID: 38420184 PMCID: PMC10897878 DOI: 10.1021/acsanm.3c05470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 03/02/2024]
Abstract
Focused-electron-beam-induced deposition is a promising technique for patterning nanomagnets in a single step. We fabricate cobalt nanomagnets in such a process and characterize their content, saturation magnetization, and stray magnetic field profiles by using a combination of transmission electron microscopy and scanning nitrogen-vacancy (NV) magnetometry. We find agreement between the measured stray field profiles and saturation magnetization with micromagnetic simulations. We further characterize magnetic domains and grainy stray magnetic fields in the nanomagnets and their halo side-deposits. This work may aid in the evaluation of Co nanomagnets produced through focused electron-beam-induced deposition for applications in spin qubits, magnetic field sensing, and magnetic logic.
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Affiliation(s)
- Liza Žaper
- Department
of Physics, University of Basel, 4056 Basel, Switzerland
- Qnami
AG, 4132 Muttenz, Switzerland
| | | | - Marcus Wyss
- Swiss
Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Boris Gross
- Department
of Physics, University of Basel, 4056 Basel, Switzerland
| | - Kai Wagner
- Department
of Physics, University of Basel, 4056 Basel, Switzerland
| | - Martino Poggio
- Department
of Physics, University of Basel, 4056 Basel, Switzerland
- Swiss
Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Floris Braakman
- Department
of Physics, University of Basel, 4056 Basel, Switzerland
- Swiss
Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
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