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Dynamic-load-enabled ultra-low power multiple-state RRAM devices.

Yang X, Chen IW - Sci Rep (2012)

Bottom Line: Bipolar resistance-switching materials allowing intermediate states of wide-varying resistance values hold the potential of drastically reduced power for non-volatile memory.This approach is entirely scalable and applicable to other bipolar RRAM with intermediate states.The projected power is 12 nW for a 100 × 100 nm(2) device and 500 pW for a 10 × 10 nm(2) device.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6272, USA.

ABSTRACT
Bipolar resistance-switching materials allowing intermediate states of wide-varying resistance values hold the potential of drastically reduced power for non-volatile memory. To exploit this potential, we have introduced into a nanometallic resistance-random-access-memory (RRAM) device an asymmetric dynamic load, which can reliably lower switching power by orders of magnitude. The dynamic load is highly resistive during on-switching allowing access to the highly resistive intermediate states; during off-switching the load vanishes to enable switching at low voltage. This approach is entirely scalable and applicable to other bipolar RRAM with intermediate states. The projected power is 12 nW for a 100 × 100 nm(2) device and 500 pW for a 10 × 10 nm(2) device. The dynamic range of the load can be increased to allow power to be further decreased by taking advantage of the exponential decay of wave-function in a newly discovered nanometallic random material, reaching possibly 1 pW for a 10×10 nm(2) nanometallic RRAM device.

No MeSH data available.


Related in: MedlinePlus

Simulated R–V curves for different cell area A using parallel circuit model in Figure 2(b).Percentage in the bracket shows F at plateau resistance. Simulation parameters: Vc*(V) = ±(1.35±0.15), Rl(Ω) = 300, rL(Ω) = 500, , where V is voltage in volt.
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f5: Simulated R–V curves for different cell area A using parallel circuit model in Figure 2(b).Percentage in the bracket shows F at plateau resistance. Simulation parameters: Vc*(V) = ±(1.35±0.15), Rl(Ω) = 300, rL(Ω) = 500, , where V is voltage in volt.

Mentions: To clarify (b), we simulated the R–V hysteresis under a constant Rl for A spanning over 4 orders of magnitude using the model in Figure 2b. (See Method for more details. Also note that ARlemerges as the control parameter for the switching behavior.) As shown in Figure 5, as the area decreases, the R–V curves develop an expanding gap (to about 7 orders of magnitude) between the plateau resistance and the HRS resistance, the latter indeed scales with A−1. Meanwhile, off-switching continues to occur between 1 V and 2 V even though the transition is no longer abrupt at small ARl. (The abrupt transition is due to the negative slope dV/dVc, which becomes positive definite at small ARl.) While the detailed outcome of the simulated results (e.g., the F value of the plateau state) obviously depends on the parameter used, such as Rl which we assumed to be area-independent, these findings do suggest that item (b) should not be a concern, thus lending support to our scaling hypothesis under a dynamic load. Moreover, since the plateau resistance does increase at smaller A, meaning that Rc>Rl in such case, for a sufficiently small A there will be less need for compliance control rendered by Rex. As a result, Ron should increase less rapidly at small A than indicated by Figure 4d.


Dynamic-load-enabled ultra-low power multiple-state RRAM devices.

Yang X, Chen IW - Sci Rep (2012)

Simulated R–V curves for different cell area A using parallel circuit model in Figure 2(b).Percentage in the bracket shows F at plateau resistance. Simulation parameters: Vc*(V) = ±(1.35±0.15), Rl(Ω) = 300, rL(Ω) = 500, , where V is voltage in volt.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473363&req=5

f5: Simulated R–V curves for different cell area A using parallel circuit model in Figure 2(b).Percentage in the bracket shows F at plateau resistance. Simulation parameters: Vc*(V) = ±(1.35±0.15), Rl(Ω) = 300, rL(Ω) = 500, , where V is voltage in volt.
Mentions: To clarify (b), we simulated the R–V hysteresis under a constant Rl for A spanning over 4 orders of magnitude using the model in Figure 2b. (See Method for more details. Also note that ARlemerges as the control parameter for the switching behavior.) As shown in Figure 5, as the area decreases, the R–V curves develop an expanding gap (to about 7 orders of magnitude) between the plateau resistance and the HRS resistance, the latter indeed scales with A−1. Meanwhile, off-switching continues to occur between 1 V and 2 V even though the transition is no longer abrupt at small ARl. (The abrupt transition is due to the negative slope dV/dVc, which becomes positive definite at small ARl.) While the detailed outcome of the simulated results (e.g., the F value of the plateau state) obviously depends on the parameter used, such as Rl which we assumed to be area-independent, these findings do suggest that item (b) should not be a concern, thus lending support to our scaling hypothesis under a dynamic load. Moreover, since the plateau resistance does increase at smaller A, meaning that Rc>Rl in such case, for a sufficiently small A there will be less need for compliance control rendered by Rex. As a result, Ron should increase less rapidly at small A than indicated by Figure 4d.

Bottom Line: Bipolar resistance-switching materials allowing intermediate states of wide-varying resistance values hold the potential of drastically reduced power for non-volatile memory.This approach is entirely scalable and applicable to other bipolar RRAM with intermediate states.The projected power is 12 nW for a 100 × 100 nm(2) device and 500 pW for a 10 × 10 nm(2) device.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6272, USA.

ABSTRACT
Bipolar resistance-switching materials allowing intermediate states of wide-varying resistance values hold the potential of drastically reduced power for non-volatile memory. To exploit this potential, we have introduced into a nanometallic resistance-random-access-memory (RRAM) device an asymmetric dynamic load, which can reliably lower switching power by orders of magnitude. The dynamic load is highly resistive during on-switching allowing access to the highly resistive intermediate states; during off-switching the load vanishes to enable switching at low voltage. This approach is entirely scalable and applicable to other bipolar RRAM with intermediate states. The projected power is 12 nW for a 100 × 100 nm(2) device and 500 pW for a 10 × 10 nm(2) device. The dynamic range of the load can be increased to allow power to be further decreased by taking advantage of the exponential decay of wave-function in a newly discovered nanometallic random material, reaching possibly 1 pW for a 10×10 nm(2) nanometallic RRAM device.

No MeSH data available.


Related in: MedlinePlus