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Stacked 3D RRAM Array with Graphene/CNT as Edge Electrodes.

Bai Y, Wu H, Wang K, Wu R, Song L, Li T, Wang J, Yu Z, Qian H - Sci Rep (2015)

Bottom Line: The electrical results reveal that the RRAM devices could switch normally with this very thin edge electrode at nanometer scale.Meanwhile, benefited from the asymmetric carrier transport induced by Schottky barrier at metal/CNT and oxide/CNT interfaces, a selector built-in 3D RRAM structure using CNT as edge electrode is successfully fabricated and characterized.Furthermore, the discussion of high array density potential is presented.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microelectronics, Tsinghua University, Beijing, China, 100084.

ABSTRACT
There are two critical challenges which determine the array density of 3D RRAM: 1) the scaling limit in both horizontal and vertical directions; 2) the integration of selector devices in 3D structure. In this work, we present a novel 3D RRAM structure using low-dimensional materials, including 2D graphene and 1D carbon nanotube (CNT), as the edge electrodes. A two-layer 3D RRAM with monolayer graphene as edge electrode is demonstrated. The electrical results reveal that the RRAM devices could switch normally with this very thin edge electrode at nanometer scale. Meanwhile, benefited from the asymmetric carrier transport induced by Schottky barrier at metal/CNT and oxide/CNT interfaces, a selector built-in 3D RRAM structure using CNT as edge electrode is successfully fabricated and characterized. Furthermore, the discussion of high array density potential is presented.

No MeSH data available.


(a) The Schematic diagram of two-layer 3D Ta2O5-x/TaOy RRAM with graphene edge electrode; the physical structure was characterized by (b) TEM image and (c) magnified false-color EELS map in cross-sectional view and (d) optical microscope image in top view; (e) the Raman spectra indicated the single layer graphene; (f) The fabrication flow of the single 3D RRAM cell.
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f2: (a) The Schematic diagram of two-layer 3D Ta2O5-x/TaOy RRAM with graphene edge electrode; the physical structure was characterized by (b) TEM image and (c) magnified false-color EELS map in cross-sectional view and (d) optical microscope image in top view; (e) the Raman spectra indicated the single layer graphene; (f) The fabrication flow of the single 3D RRAM cell.

Mentions: Two-layer 3D Ta2O5-x/TaOy RRAM cells are fabricated using monolayer graphene as the edge electrode. Figure 2(a) shows the schematic view of the device structure. The monolayer graphene was grown on the Pt substrate using CVD method and transferred to SiO2 substrate by an electrochemical approach23. The Pt pillar and graphene layer serve as pillar electrode and edge electrode respectively, while the transitional metal oxide (TMO) resistive switching layer is located vertically on the sidewall between pillar electrode and edge electrode. Pd is chosen as the contact metal to graphene for signal output. The cross-sectional TEM image in Fig. 2(b) and magnified false-color EELS map in Fig. 2(c) show the typical structure of 3D Ta2O5-x/TaOy RRAM devices using monolayer graphene as the edge electrode. Figure 2(d) shows the optical top view of the monolayer graphene with pillar electrode and metal contact. Raman spectrum analysis was applied on the grown graphene layer, as shown in Fig. 2(e). The position and shape of G and 2D peaks in the spectrum confirm that the graphene used in the 3D RRAM structure is a monolayer graphene with thickness of ~0.3 nm.


Stacked 3D RRAM Array with Graphene/CNT as Edge Electrodes.

Bai Y, Wu H, Wang K, Wu R, Song L, Li T, Wang J, Yu Z, Qian H - Sci Rep (2015)

(a) The Schematic diagram of two-layer 3D Ta2O5-x/TaOy RRAM with graphene edge electrode; the physical structure was characterized by (b) TEM image and (c) magnified false-color EELS map in cross-sectional view and (d) optical microscope image in top view; (e) the Raman spectra indicated the single layer graphene; (f) The fabrication flow of the single 3D RRAM cell.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562297&req=5

f2: (a) The Schematic diagram of two-layer 3D Ta2O5-x/TaOy RRAM with graphene edge electrode; the physical structure was characterized by (b) TEM image and (c) magnified false-color EELS map in cross-sectional view and (d) optical microscope image in top view; (e) the Raman spectra indicated the single layer graphene; (f) The fabrication flow of the single 3D RRAM cell.
Mentions: Two-layer 3D Ta2O5-x/TaOy RRAM cells are fabricated using monolayer graphene as the edge electrode. Figure 2(a) shows the schematic view of the device structure. The monolayer graphene was grown on the Pt substrate using CVD method and transferred to SiO2 substrate by an electrochemical approach23. The Pt pillar and graphene layer serve as pillar electrode and edge electrode respectively, while the transitional metal oxide (TMO) resistive switching layer is located vertically on the sidewall between pillar electrode and edge electrode. Pd is chosen as the contact metal to graphene for signal output. The cross-sectional TEM image in Fig. 2(b) and magnified false-color EELS map in Fig. 2(c) show the typical structure of 3D Ta2O5-x/TaOy RRAM devices using monolayer graphene as the edge electrode. Figure 2(d) shows the optical top view of the monolayer graphene with pillar electrode and metal contact. Raman spectrum analysis was applied on the grown graphene layer, as shown in Fig. 2(e). The position and shape of G and 2D peaks in the spectrum confirm that the graphene used in the 3D RRAM structure is a monolayer graphene with thickness of ~0.3 nm.

Bottom Line: The electrical results reveal that the RRAM devices could switch normally with this very thin edge electrode at nanometer scale.Meanwhile, benefited from the asymmetric carrier transport induced by Schottky barrier at metal/CNT and oxide/CNT interfaces, a selector built-in 3D RRAM structure using CNT as edge electrode is successfully fabricated and characterized.Furthermore, the discussion of high array density potential is presented.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microelectronics, Tsinghua University, Beijing, China, 100084.

ABSTRACT
There are two critical challenges which determine the array density of 3D RRAM: 1) the scaling limit in both horizontal and vertical directions; 2) the integration of selector devices in 3D structure. In this work, we present a novel 3D RRAM structure using low-dimensional materials, including 2D graphene and 1D carbon nanotube (CNT), as the edge electrodes. A two-layer 3D RRAM with monolayer graphene as edge electrode is demonstrated. The electrical results reveal that the RRAM devices could switch normally with this very thin edge electrode at nanometer scale. Meanwhile, benefited from the asymmetric carrier transport induced by Schottky barrier at metal/CNT and oxide/CNT interfaces, a selector built-in 3D RRAM structure using CNT as edge electrode is successfully fabricated and characterized. Furthermore, the discussion of high array density potential is presented.

No MeSH data available.