Deposition spot profiles by XPS for at low energy and at high energies—two extremes of the beam focusing conditions. Also shown are the best fit model profiles (dashed curves) and the resulting convoluted fits (solid curves). (Inset) Relative Ir coverages measured in the center of spot (gray) and calculated total spot coverage (black).
Ir XPS for ( and 10) as deposited, after heating to 750 K, and after 5 ISS runs. These data were taken for depositions with different Ir coverages in the XPS analysis area ( ML; ML; ML). The solid vertical lines indicate the and binding energies in bulk iridium. The dashed line notes the final state correction obtained for clusters of similar size on (Ref. 9).
ISS spectra for . Top: 1 keV ISS before and after sputter removal of the film, also indicating the background subtraction process. Bottom: 500 eV ISS showing accumulation of damage from 4 min of beam exposure.
ISS spectra for ML (, 2, and 10) for different deposition energies, before and after heating to 750 K. The “as deposited” and “after heating” experiments were done on different cluster spots to eliminate possible effects of ISS damage. The bottom spectrum for 110 K atom deposition is the fourth ISS in the sequence summarized in Fig. 6.
(Top) ratios for 0.1 ML (, 2, and 10) soft landed on at room temperature as a function of 0.5 keV exposure. (Bottom) Analogous plots for new samples of the same compositions, heated to 750 K prior to analysis.
Ratios for 0.1 ML ( and 10) soft landed on at 110 K as a function of 0.5 keV exposure.
(Top) ratios for 0.10 ML (, 2, and 10) hard landed on room temperature as a function of 0.5 keV exposure. (Bottom) Analogous plots for new samples of the same compositions, heated to 750 K prior to analysis.
(a) Top: TPD from 0.05 ML after a 5 L exposure at 105 K. Bottom: TPD from 0.09 ML following adventitious exposure to chamber background during sample preparation. In both cases, the deposition energy was 1.5 eV per atom. (b) Temperature-programmed ISS demonstrating that CO is the dominant adventitious adsorbate affecting ISS (see text).
Comparison of ratios to metal/substrate ratios measured previously for and . Ratios have been scaled to 0.1 ML Ir surface coverage and corrected for the differing substrate detection efficiency for and as described in text.
ISS ratio as a function of initial CO coverage and exposure to 1 keV for 0.10 ML landed at 1 eV per atom.
Article metrics loading...
Full text loading...