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Physical and chemical mechanisms in oxide-based resistance random access memory.

Chang KC, Chang TC, Tsai TM, Zhang R, Hung YC, Syu YE, Chang YF, Chen MC, Chu TJ, Chen HL, Pan CH, Shih CC, Zheng JC, Sze SM - Nanoscale Res Lett (2015)

Bottom Line: Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device.The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process.Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.

ABSTRACT
In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

No MeSH data available.


Related in: MedlinePlus

Filament 3D speculation diagram. The inset shows the hexagonal-close-packed structure, where the light blue region is the effective cross section area of each atom [5].
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Fig8: Filament 3D speculation diagram. The inset shows the hexagonal-close-packed structure, where the light blue region is the effective cross section area of each atom [5].

Mentions: Based on the above experiment results, the reaction began from the first layer of conductive filament close to the TiN electrode during the reset procedure. During the reaction in the first layer, the effective cross section of filament will reduce and cause the variation of resistance in RRAM. Therefore, we propose a three-dimensional diagram of filament in the LRS of RRAM to represent the continuous conduction path between TiN and Ti electrodes as shown in Figure 8. The effective conduction area of the filament would be reduced due to oxygen atoms oxidized with filament one after another, leading to the rise of the resistance value of RRAM. Because the resistance value is inversely proportional to the effective conduction area determined by the number of component atoms of conduction filament, the ratio of resistance with and without i atoms removed away in effective cross section is RN −i/RN = N/N − i. Therefore, the quantized variation of resistance can be attributed to the atomic-level reaction on the filament during the reset procedure. In order to clarify the switching mechanism, the resistance switching characteristics of RRAM were measured in the 4-K environment to eliminate the thermodynamic effects during reset procedure. The step-by-step resistance change shown in Figure 4 can be explained by the cross-sectional effective atom removal, which will result in the quantized reduction of the resistance.Figure 8


Physical and chemical mechanisms in oxide-based resistance random access memory.

Chang KC, Chang TC, Tsai TM, Zhang R, Hung YC, Syu YE, Chang YF, Chen MC, Chu TJ, Chen HL, Pan CH, Shih CC, Zheng JC, Sze SM - Nanoscale Res Lett (2015)

Filament 3D speculation diagram. The inset shows the hexagonal-close-packed structure, where the light blue region is the effective cross section area of each atom [5].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4388104&req=5

Fig8: Filament 3D speculation diagram. The inset shows the hexagonal-close-packed structure, where the light blue region is the effective cross section area of each atom [5].
Mentions: Based on the above experiment results, the reaction began from the first layer of conductive filament close to the TiN electrode during the reset procedure. During the reaction in the first layer, the effective cross section of filament will reduce and cause the variation of resistance in RRAM. Therefore, we propose a three-dimensional diagram of filament in the LRS of RRAM to represent the continuous conduction path between TiN and Ti electrodes as shown in Figure 8. The effective conduction area of the filament would be reduced due to oxygen atoms oxidized with filament one after another, leading to the rise of the resistance value of RRAM. Because the resistance value is inversely proportional to the effective conduction area determined by the number of component atoms of conduction filament, the ratio of resistance with and without i atoms removed away in effective cross section is RN −i/RN = N/N − i. Therefore, the quantized variation of resistance can be attributed to the atomic-level reaction on the filament during the reset procedure. In order to clarify the switching mechanism, the resistance switching characteristics of RRAM were measured in the 4-K environment to eliminate the thermodynamic effects during reset procedure. The step-by-step resistance change shown in Figure 4 can be explained by the cross-sectional effective atom removal, which will result in the quantized reduction of the resistance.Figure 8

Bottom Line: Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device.The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process.Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.

ABSTRACT
In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

No MeSH data available.


Related in: MedlinePlus