A Super Nonlinear Electrodeposition-diffusioncontrolled

Transcription

1 Supplementary Information A Super Nonlinear Electrodeposition-diffusioncontrolled Thin Film Selector Xinglong Ji 1, Li Song 1, Wei He 1, Kejie Huang 2, Zhiyuan Yan 1, Shuai Zhong 1, Yishu Zhang 1 and Rong Zhao* 1 1 Department of Engineering Product Design, Singapore University of Technology and Design, 8 Somapah Road, , Singapore 2 Institute of Information and Communication Engineering, Zhejiang University, Hangzhou, , China *Corresponding author Rong Zhao zhao_rong@sutd.edu.sg S-1

2 Figure S1. The V th and OFF state current are found to be highly related to the Ag concentration. (a) Distribution and cumulative probability of OFF state resistance for three different Ag doping compositions. (b) DC sweeping for different Ag concentrations. The ultra-low leakage of the proposed selector device can be ascribed to ultra-high resistance of 10% Ag composition (up to 10 9 Ω). As Ag concentration further increases, the device resistance dramatically decreases. Figure S2. I-V sweeping characteristics with different compliance current and 1S1R implemtation. (a) I-V curves under different compliance currents. The drive current can be as high as 10 µa. And refer to the OFF current in Figure 1(c), the ON/OFF ratio is larger than (b) Switching characteristic of TiO 2 resistive memory integrated with bidirectional selector, which can imitate the 1 selector 1 resistive NVM (1S1R) structure. S-2

3 Figure S3. Device to device variability in a 6 6 crossbar array. (a) Top view of a 6 6 crossbar array of selector device. (b) Threshold voltage distribution of the 6 6 crossbar structure of selector device, showing good device to device variability. Figure S4. The breakdown induced by cycling can be recovered by thermal annealing. (a) I- V curves of breakdown device (red line) and recovered device (green line). (b) Device resistance evolution with time at 80 o C. After breakdown, the device stays at low resistance state and cannot return to high resistance state. However, it is surprising to find that the selection characteristic of device can be fully recovered by thermal annealing (80 o C for 12 hours). This indicates that the breakdown may relate to the formation of metallic conductive bridging between TE and BE and thermal treatment can accelerate the diffusion of metallic bridge, resulting the recovery of the selector. S-3

4 Figure S5. HRTEM image of the Ag clustering region and Ag diffusing region. Both two regions (clustering region and diffusing region) maintain in amorphous phase. Figure S6. TEM and EDX analyses based on a pristine device. (a) Cross-sectional TEM S-4

5 image of pristine selector device. (b) Enlarged bright field image of switching layer. (c) EDX mapping image of Ag of the switching layer. The switching layer of pristine device shows uniform contrast, and no Ag-rich cluster can be identified. Figure S7. 3 V voltage was applied to the lateral device until the device was switched to low resistance state, exhibiting as a memory switching. (a) SEM image capturing the Ag filament in lateral device. (b) EDX mapping of the Ag filament in the shorting lateral device. Figure S8. (a) Molecular dynamics model of glassy GST at 300K. (b) Schematic illustration of the Anderson-Stuart model. Ag+ ion migrates between two equivalent sites of non- S-5

6 bonding Te (NBT) atoms. The bonding Te (BT) atoms create a doorway and inherent strain energy the Ag+ must overcome before migrating through the material. Left: without bias, Right: with bias. Table S1. Bond lengths of Ag-S, Ag-Se, Ag-Te in Ge-chalcogenide glass materials Ag-Ge-S Ag-Ge-Se Ag-Ge-Te Bond Length Ag-S ( Å) 1 Ag-Se (2.67 Å) 2 Ag-Te (2.77 Å) 3 References (1) Lee, J. H.; Owens, A. P.; Pradel, A.; Hannon, A. C.; Ribes, M. and Elliott, S. R. Structure determination of Ag-Ge-S glasses using neutron diffraction. Phys. Rev. B, 1996, 54(6), (2) Piarristeguy, A.; Mirandou, M.; Fontana, M. and Arcondo, B. X-ray analysis of GeSeAg glasses. J. Non-Cryst. Solids, 2000, 273(1), (3) Sakurai, M.; Kakinuma, F.; Matsubara, E. and Suzuki, K. Partial structure analysis of amorphous Ge 15 Te 80 M 5 (M = Cu, Ag and In). J. Non-Cryst. Solids, 2002, 312, S-6