Extended Data Fig. 1: Cross-sectional transmission electron microscopy (TEM) bright field (BF) and high-angle annular dark-field (HAADF) images of the NFPCM in the set state.
From: Phase-change memory via a phase-changeable self-confined nano-filament
a. An illustration of the NFPCM with the normal forming condition. b. The TEM BF image of the NFPCM, formed with the normal forming condition. c. The TEM HAADF image exhibiting a highly confined filament is formed in the a-Si layer with approximately 5.5 nm of diameter. d. An illustration of the NFPCM with the aggressive forming condition to form a thick filament. e. The TEM BF image of the NFPCM, formed with the aggressive forming condition. f. The TEM HAADF image of a thick filament in the a-Si layer. Since heavier Te atoms appear brighter than lighter Si atoms in the HAADF image, c and f indicate that the Te atoms are inserted into the a-Si layer and form a SiTex filament. Detailed explanations about forming strategies are provided in the Methods section.