Oxidation of diamond films by atomic oxygen: High resolution electron energy loss spectroscopy studies

Abstract

Investigation of oxygen-related defects and the electrical properties of atomic layer deposited HfO 2 films using electron energy-loss spectroscopy High resolution electron energy loss spectroscopy study of Fomblin Z-tetraol thin filmsa) A combined scanning tunneling microscopy and electron energy loss spectroscopy study on the formation of thin, well-ordered β-Ga 2 O 3 films on CoGa (001) Diamond surface oxidation by atomic oxygen, annealing up to ϳ700°C, and in situ exposure to thermally activated hydrogen were studied by high resolution electron energy loss spectroscopy ͑HREELS͒. After atomic oxygen ͑AO͒ exposure, HREELS revealed peaks associated with CH x groups, carbonyl, ether, and peroxide-type species and strong quenching of the diamond optical phonon and its overtones. Upon annealing of the oxidized surfaces, the diamond optical phonon overtones at 300 and 450 meV emerge and carbonyl and peroxide species gradually desorb. The diamond surface was not completely regenerated after annealing to ϳ700°C and in situ exposure to thermally activated hydrogen, probably due to the irreversible deterioration of the surface by AO.

Hydrogen plasma and atomic oxygen treatments of diamond: Chemical versus morphological effects

“…[7][8][9][10] The correlation between chemical modification and morphological changes is important both from fundamental and applied points of views. 10,21 Following the exposures, the morphology of the polycrystalline diamond films was investigated using atomic force microscopy ͑AFM͒, and the surface bonding states were measured using high resolution electron energy loss spectroscopy ͑HREELS͒. [18][19][20] However, morphological changes following exposures to hydrogen plasma and AO have not been reported.…”

“…10,21 The system was operated at a pressure of 50 mTorr, gas flow of 10 SCCM ͑SCCM denotes cubic centimeter per minute at STP͒ and power of 2000 W. During exposure the diamond samples were maintained at room temperature and located in the afterglow of the plasma system after two right angle bends in the gas tube system emerging from the plasma source. 10,21 The system was operated at a pressure of 50 mTorr, gas flow of 10 SCCM ͑SCCM denotes cubic centimeter per minute at STP͒ and power of 2000 W. During exposure the diamond samples were maintained at room temperature and located in the afterglow of the plasma system after two right angle bends in the gas tube system emerging from the plasma source.…”

“…10,21 The system was operated at a pressure of 50 mTorr, gas flow of 10 SCCM ͑SCCM denotes cubic centimeter per minute at STP͒ and power of 2000 W. During exposure the diamond samples were maintained at room temperature and located in the afterglow of the plasma system after two right angle bends in the gas tube system emerging from the plasma source. 10 Exposure to hydrogen plasma was performed in a MW plasma reactor, at a pressure of 50 Torr, flow of 250 SCCM H 2 gas, and MW power of 1100 W, for a period of 30 min. 21 The sample was exposed for 17 h resulting in AO fluence of 5.5ϫ 10 19 atoms cm −2 .…”

“…21 The sample was exposed for 17 h resulting in AO fluence of 5.5ϫ 10 19 atoms cm −2 . 10 The morphology of the samples was studied using AFM ͑Nanoscope IV MultiMode from Veeco͒ operated in tapping mode. During exposure the sample temperature was maintained at 650°C.…”

“…During exposure the sample temperature was maintained at 650°C. 10 The vibrational spectrum of a pristine diamond film ͓Fig. 23,24 HREELS studies were carried out using a Delta 0.5 spectrometer ͑VSI-SPECS͒; detailed description of the operation parameters can be found elsewhere.…”