Fig. 6: Nanoscale chemical analysis of Ta oxide.
From: Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation
a Darkfield STEM image of the Ta2O5/Ta interface. Electron energy loss spectra (EELS) taken from the locations indicated in (a) are provided in (b) and (c). b EELS signal taken from the specified region demonstrating how the tantalum O2,3 edge evolves with position. c EELS signal taken from the specified region demonstrating how oxygen K edge evolves as a function of position. The dotted lines indicate minimal variation in the position of various features of the spectra. This suggests that the oxygen stoichiometry remains consistent throughout the oxide region. Scale bars represent 10 nm.
