2017/09/30 by Matthias Brauns, Sergey V. Amitonov, Paul-Christiaan Spruijtenburg +1
Materials Science · Physics and Astronomy · #Aluminium #Aluminium oxide #Chemical and Physical Properties of Materials #Fabrication #Palladium #Quantum and electron transport phenomena #Quantum dot #Qubit #Semiconductor Quantum Structures and Devices #Silicon #cond-mat.mes-hall
paper · pdf · doi:10.1038/s41598-018-24004-y
published as Scientific Reports 8, 5690, (2018)
openalex created_date 2017/10/06 · openalex publication_date 2018/04/04 · arxiv created 2018/04/20 · arxiv updated 2018/04/23 · openalex updated_date 2026/08/05
We replace the established aluminium gates for the formation of quantum dots in silicon with gates made from palladium. We study the morphology of both aluminium and palladium gates with transmission electron microscopy. The native aluminium oxide is found to be formed all around the aluminium gates, which could lead to the formation of unintentional dots. Therefore, we report on a novel fabrication route that replaces aluminium and its native oxide by palladium with atomic-layer-deposition-grown aluminium oxide. Using this approach, we show the formation of low-disorder gate-defined quantum dots, which are reproducibly fabricated. Furthermore, palladium enables us to further shrink the gate design, allowing us to perform electron transport measurements in the few-electron regime in devices comprising only two gate layers, a major technological advancement. It remains to be seen, whether the introduction of palladium gates can improve the excellent results on electron and nuclear spin qubits defined with an aluminium gate stack.