Hydroxylated α-Al2O3 (0001) surfaces and metal/α-Al2O3 (0001) interfaces

Interaction of nanostructured metal overlayers with oxide surfaces

“…The interfacial OH can be stable even in the presence of two ML Cu [492,493]. Similar to the theoretical results, XPS experimental data do not support any strong chemical reactions between surface OH and Cu adatoms [460]. Lodziana et al [481] have suggested that surface defects which are introduced by the hydroxylation, rather than surface OH groups, are responsible for the experimentally observed enhancement of Cu interaction.…”

“…(1 × 1); 63% inward relaxation of top Al layer; H presence on surface even after annealing at 1100 • C TOF-SARS, LEED [451] Annealing in air at 1500 • C, 3 h (1 × 1); 51% inward relaxation of top Al layer CTR diffraction [25] Heating at 650 • C using atomic deuterium beam Exposure of Al-terminated surface to >1 Torr water followed by oxygen plasma at RT 1 ML coverage of surface OH XPS [459] Exposure of clean surface to water drops followed by oxygen plasma at RT 0.5 ± 0.1 ML coverage of surface OH XPS [460] Exposure to water vapor Formation of surface OH XPS [461][462][463] Other surface phases 1 keV Ar bombardment 3 nm γ -Al 2 O 3 layer with high density defects TEM [464] UHV heating or ion sputtering Surface Al-rich phases; With increasing T : change from (2 × 2),…”

“…The surface OH groups are very sensitive to electron beam illumination, Ar + sputtering, UHV heating, and adsorption of reactive metals. For example, exposure of a hydroxylated Al 2 O 3 surface to a large electron beam dose or high energy ion sputtering resulted in dehydroxylation of the surface [454,460,462,487]. High temperature annealing or Al deposition can transform a hydroxylated surface to an Al-terminated surface [460,490].…”

“…Experimental and theoretical work has shown that others metals, such as Al [455,460,494], Ti [455,488], Rh [489], and Co [459,460], can react with the surface OH to form oxidized metal overlayers at submonolayer coverage. For example, Chambers et al [459] showed that Co deposition on fully hydroxylated sapphire surfaces is accompanied by oxidation to Co 2+ and removal of OH (Fig.…”

A Substrate-Reclamation Technology for GaN-Based Lighting-Emitting Diodes Wafer

“…These results show the Al2p, Al2s, O2s, and O1s peaks located near 74.4, 118, 23, and 531 eV, respectively. The binding energy of O and Al corresponds to that of O and Al in Al2O3 (i.e., the sapphire substrate) [13,14]. This result is consistent with an exposed PSS surface without Ga and demonstrates that no GaO2H is present at the surfaces of the exposed PSS.…”