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The interaction of oxygen molecules with Ar+ sputter-etched (amorphized) Ge(100) and rf sputter-deposited amorphous germanium carbides (a-Ge1−xCx:H), 0≤x≤0.5, was investigated using Auger measurements and core-level, valence-band, and high-resolution electron energy-loss spectroscopies (EELS). A film covered with native oxide was also studied. Samples were exposed to oxygen following surface cleaning by Ar+ etching. This procedure, as previously reported, preferentially removed hydrogen bonded to Ge in a-Ge:H and a-Ge1−xCx:H films. High-resolution EELS indicated dissociative chemisorption of oxygen on Ge in all Ar+-etched samples used in this study. The oxygen appears to be bonded to Ge mainly in an isolated bridge form (+1 oxidation state) at the early stages of oxidation. Even when the surface was pre-exposed to 104-L O2, subsequent exposure to hydrogen atoms indicated the existence of a high density of bonds available for hydrogen bonding, contrary to observations at Ge(111). Under these conditions the Ge–H stretch loss split into two features separated by ∼8 meV. Possible bonding configurations, including oxygen bridging between the first and second layers, are discussed. Valence-band EEL spectra exhibited a single oxygen induced loss at an energy loss similar to that observed for single crystals of Ge. Core-level shifts due to oxidation were not observed as was the case for room-temperature adsorption on single crystals. In addition, no change in the Ge(MVV) Auger line shape was induced by oxygen chemisorption, in contrast to previously observed hydrogen related changes. These results are compared to those reported for single crystals of Ge.

Improving the vacuum degree inside the vacuum device is vital to the performance and lifespan of the vacuum device. The influence of the Ti and ZrCoCe barrier layers on the performance of ZrCoCe getter films, including sorption performance, anti-vibration performance, and binding force between the ZrCoCe getter film and the Ge substrate were investigated. In this study, the Ti and ZrCoCe barrier layers were deposited between the ZrCoCe getter films and Ge substrates. The microtopographies of barrier layers and the ZrCoCe getter film were analyzed using scanning electron microscopes. The sorption performance was evaluated using the constant-pressure method. The surface roughness of the barrier layers and the getter films was analyzed via atomic force microscopy. The binding force was measured using a nanoscratch tester. The anti-vibration performance was examined using a vibration test bench. The characterization results revealed that the Ti barrier layer significantly improved the sorption performance of the ZrCoCe getter film. When the barrier material was changed from ZrCoCe to Ti, the initial sorption speed of the ZrCoCe getter film increased from 141 to 176 cm3·s−1·cm−2, and the sorption quantity increased from 223 to 289 Pa·cm3·cm−2 in 2 h. The binding force between the Ge substrate and the ZrCoCe getter film with the Ti barrier layer was 171 mN, whereas that with the ZrCoCe barrier layer was 154 mN. The results showed that the Ti barrier layer significantly enhanced the sorption performance and binding force between the ZrCoCe getter film and the Ge substrate, which improved the internal vacuum level and the stability of the microelectromechanical system vacuum devices.