Photoelectron spectra of the O 1s core-level for “exfoliated” HOPG samples before (Black—bottom spectra) and after (Red—top spectra) exposure to (i) 102 L, (ii) 104 L, (iii) 106 L, (iv) 108 L, (v) 1010 L, (vi) 1012 L of ozone.
(a) O 1s core-level feature for “exfoliated” HOPG after (i) no exposure (ii) 100 × 1s cycles of ozone at room temperature (iii) and 100 × 1 s cycles of ozone at 200 °C, in the ALD reactor. (b) C 1s difference spectra obtained by the subtraction of the “exfoliated” HOPG spectra from spectra obtained after (ii) 100 × 1 s cycles of ozone at room temperature and (iii) 100 × 1 s cycles of ozone at 200 °C, in the ALD reactor.
Photoelectron spectra for (a) the O 1s, (b) Al 2p, and (c) C 1s core-levels for Al2O3 grown on “exfoliated” HOPG at room temperature with 6 cycles of TMA and ozone precursors. For (a) the first pulse was TMA, for (b) the first pulse was ozone.
(a) 3 μm × 3 μm AFM image after TMA first process. (b) 3 μm × 3 μm AFM image of ozone first process. It is clear that the TMA first process results in an almost conformal layer that can be used for seeding further ALD. The ozone first process results in deposition primarily on step edges.
Photelectron spectra of (a) O 1s, (b) Al 2p for (i) 6 ALD half-cycles interupted for 6 hours of UHV XPS analysis between each half cycle and (ii) 3 uninterupted ALD cycles (6 half-cycle equivalent) on “exfoliated + annealed” HOPG.
Photoelectron spectra of (a) O 1s and (b) Al 2p core-levels for Al2O3 grown on “exfoliated + Annealed” HOPG at room temperature with 18 cycles of TMA and ozone precursors. Precursor pulses were both 0.2 s, while the nitrogen purge time was (i) 30 s and (ii) 300 s.
Photoelectron spectra of the C 1s (a) and (b), and O 1s (c) and (d) core-level features for (i) before and (ii) after a 300 °C UHV 1 h anneal for Al2O3 on HOPG (left) and HF-last silicon (right).
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