Figure 6
Differentiated counts with respect to kinetic energy (dC/dE). AES spectra vs. kinetic energy for pristine and after-switching RRAM devices. The spectra are from a typical via size of 0.4 × 0.4 μm2 and measured inside the middle of via regions (open blue square symbols for pristine and yellow solid triangle symbols for switched devices). An oxygen-deficient TaO x layer is observed after few switching cycles, confirming oxygen-deficient TaO x filament formation after SET.