biostudies-literatureUnknown603(7901)Kim SJOxidation can deteriorate the properties of copper that are critical for its use, particularly in the semiconductor industry and electro-optics applications^1-7. This has prompted numerous studies exploring copper oxidation and possible passivation strategies⁸. In situ observations have, for example, shown that oxidation involves stepped surfaces: Cu₂O growth occurs on flat surfaces as a result of Cu adatoms detaching from steps and diffusing across terraces^9-11. But even though this mechanism explains why single-crystalline copper is more resistant to oxidation than polycrystalline copper, the fact that flat copper surfaces can be free of oxidation has not been explored further. Here we report the fabrication of copper thin films that are semi-peNature434-438https://www.ebi.ac.uk/biostudies/studies/S-EPMC8930770biostudies-literatureFlat-surface-assisted and self-regulated oxidation resistance of Cu(111).PMC8930770Cho CRJeong SYKim JLee YHHa TCheon MKim SGKim YMLamichhane BKim YIKim YHJeong HYLee YKim SJKim JCfalseFlat-surface-assisted and self-regulated oxidation resistance of Cu(111).Oxidation can deteriorate the properties of copper that are critical for its use, particularly in the semiconductor industry and electro-optics applications^1-7. This has prompted numerous studies exploring copper oxidation and possible passivation strategies⁸. In situ observations have, for example, shown that oxidation involves stepped surfaces: Cu₂O growth occurs on flat surfaces as a result of Cu adatoms detaching from steps and diffusing across terraces^9-11. But even though this mechanism explains why single-crystalline copper is more resistant to oxidation than polycrystalline copper, the fact that flat copper surfaces can be free of oxidation has not been explored further. Here we report the fabrication of copper thin films that are semi-pe2022-01-01T00:00:00Z2022 Mar2025-04-21T23:09:49.63Z2025-04-05T19:06:25.829ZS-EPMC89307703529684410.1038/s41586-021-04375-5