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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.


Abrupt set procedure and multistep reset procedure for oxide-based RRAM device[5].
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Fig5: Abrupt set procedure and multistep reset procedure for oxide-based RRAM device[5].

Mentions: The typical resistance switching characteristics of Ti/HfOx/TiN cells were measured by DC voltage sweep mode shown in Figure 5. For the operation of RRAM, an irreversible forming procedure is required to activate the as-fabricated RRAM cells. A compliance current of 500 μA was set to prevent permanent breakdown during RRAM operation in DC-voltage sweeping mode. A sudden increase of the current was observed at the voltage of about 3.5 V to achieve the forming procedure. After forming process, a gradual descent of current interpreted the cell that was switched back to HRS from LRS while a positive bias was swept over the reset voltage (Vreset, 0.55 V), which is called as ‘reset procedure’ and due to the rupture of the filament. Conversely, as the negative bias was swept over the set voltage (Vset, −0.55 V), the RRAM cell will switch from HRS to LRS, i.e. ‘set procedure,’ which is attributed to the formation of filament. The inset diagram in the upper left shows that the set procedure is the transformation of HRS changed to LRS. The inset diagram in the lower right shows the reset procedure, which can be divided into different resistive stages by altering the negative stop voltage of DC sweeping cycle (Vstop). The resistance value increases with increasing the Vstop, leading to the multi-level resistance state obtained by controlling the Vstop.Figure 5


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)

Abrupt set procedure and multistep reset procedure for oxide-based RRAM device[5].
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig5: Abrupt set procedure and multistep reset procedure for oxide-based RRAM device[5].
Mentions: The typical resistance switching characteristics of Ti/HfOx/TiN cells were measured by DC voltage sweep mode shown in Figure 5. For the operation of RRAM, an irreversible forming procedure is required to activate the as-fabricated RRAM cells. A compliance current of 500 μA was set to prevent permanent breakdown during RRAM operation in DC-voltage sweeping mode. A sudden increase of the current was observed at the voltage of about 3.5 V to achieve the forming procedure. After forming process, a gradual descent of current interpreted the cell that was switched back to HRS from LRS while a positive bias was swept over the reset voltage (Vreset, 0.55 V), which is called as ‘reset procedure’ and due to the rupture of the filament. Conversely, as the negative bias was swept over the set voltage (Vset, −0.55 V), the RRAM cell will switch from HRS to LRS, i.e. ‘set procedure,’ which is attributed to the formation of filament. The inset diagram in the upper left shows that the set procedure is the transformation of HRS changed to LRS. The inset diagram in the lower right shows the reset procedure, which can be divided into different resistive stages by altering the negative stop voltage of DC sweeping cycle (Vstop). The resistance value increases with increasing the Vstop, leading to the multi-level resistance state obtained by controlling the Vstop.Figure 5

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.