Figure 4: Direct observation of a Ta-rich and O-deficient conduction channel.
From: Sub-10 nm Ta Channel Responsible for Superior Performance of a HfO2 Memristor
(a) HAADF-STEM image shows a sub-10 nm conduction channel connecting Ta top and Pt bottom electrodes. The conduction channel is brighter in the image, which means it contains more atoms with large atomic numbers (Ta in this case). (b) Comparison of core-loss EELS spectra collected at the pristine HfO2 layer, conduction channel region and Ta electrode. It indicates the conduction channel is Ta-rich. (c) O-K edge EELS spectra taken at three areas, which clearly show the conduction channel is also O-deficient.
