Effect of nitrogen-accommodation ability of electrodes in SiNx-based resistive switching devices

Physica Status Solidi (a)

Zhang

et al. 2018

Self Cite

In this paper, the resistive switching phenomena in CMOS-compatible Ta/ SiN x /Pt devices with different nitrogen concentrations are investigated. The SiN x resistance random-access memory (RRAM) devices show self-compliance RS characteristics with low operation voltage. This paper suggests that a dendric Si dangling-bond conductive channel and a nitrogen-rich SiN x layer formed at the Ta/SiN x interface are responsible for the self-compliance behavior. Lower operation current and energy consumption are achieved by increasing the nitrogen concentration of the SiN x films, which can be ascribed to increase of the band gap induced by the composition variation.

Section: Resultsmentioning

confidence: 99%

J_{S E} = \frac{4 π q m^{*} k^{2}}{h^{3}} T^{2} \exp [\frac{- q ({normalΦ}_{B} - \sqrt{q E / 4 π ϵ_{0} k_{r}})}{k T}]

Section: Resultsmentioning

confidence: 99%

Influence of Nitrogen Concentration on Self‐Compliance Resistive Switching in Ta/SiN_x/Pt RRAM Devices

Physica Status Solidi (a)

Zhang

et al. 2018

Self Cite

“…Moreover, transistors which are connected to RRAM cells cannot endure such a high voltage and may cause problems of devices size scaling. [28] We found that tantalum has great nitrogenaccommodation ability to be the electrode. [15] But both of them are not perfect: the first one cannot ensure the position of generating defects thus the CCs have a random location and shape; the second one cannot ensure the quality of films and the initial defects are in a state of random distribution, the yield and reliability is not very good.…”

mentioning

confidence: 84%

“…[28] We found that tantalum has great nitrogenaccommodation ability to be the electrode. [28] We found that tantalum has great nitrogenaccommodation ability to be the electrode.…”

mentioning

confidence: 84%

“…[28][29][30][31][32][33] Although we use a Si 3 N 4 target to deposit films, from the X-ray photoelectron spectroscopy (XPS) test result, which can be consulted from Supporting Information, we can find that the ratio of Si and N atoms is much smaller than the normal stoichiometric ratio. [28][29][30][31][32][33] Although we use a Si 3 N 4 target to deposit films, from the X-ray photoelectron spectroscopy (XPS) test result, which can be consulted from Supporting Information, we can find that the ratio of Si and N atoms is much smaller than the normal stoichiometric ratio.…”

mentioning

confidence: 99%

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Enhanced Switching Stability in Forming‐Free SiN_x Resistive Random Access Memory Devices with Low Power Consumptions Based on Local Pt Doping in a Stacked Structure

Yang

et al. 2018

Adv Elect Materials

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a high forming voltage may lead to current overshoot effect. [21,22] High power consumption is also a severe problem led by high forming voltage. Moreover, transistors which are connected to RRAM cells cannot endure such a high voltage and may cause problems of devices size scaling. Therefore, it is necessary to explore RRAM devices which have forming-free RS characteristic.There are many kinds of methods to deposit a forming-free film, and there are two kind of common types: One is by simply reducing the thickness of film or inserting a metal layer for reducing the overall insulation of the film, and make the forming voltage reduce to a very low level (approximate to the Set voltage); another is by using a substoichiometry film, because there are plenty of defects, the film will initially be in low resistance state (LRS). [15] But both of them are not perfect: the first one cannot ensure the position of generating defects thus the CCs have a random location and shape; the second one cannot ensure the quality of films and the initial defects are in a state of random distribution, the yield and reliability is not very good. Besides, in the present study of SiN x -based RRAM devices, due to the influence of preparation process (such as plasma enhanced chemical vapor deposition (PECVD)), there are always hydrogen atoms in the films. But unfortunately, the specific role of hydrogen atoms is still unclear and has some different kinds of comprehensions from scholars. [25][26][27] It will be better if we can exclude hydrogen atoms from the films. In this situa tion, we need a specific method that can solve all the questions above.In our previous work, we have investigated the effect of nitrogen-accommodation ability of electrodes in SiN x -based RS devices. [28] We found that tantalum has great nitrogenaccommodation ability to be the electrode. Besides, we have investigated the influence of nitrogen concentration on selfcompliance RS in Ta/SiN x /Pt RRAM devices and built a reliable RS model. [29] It seems that if we decrease the value of x, there will be more defects in the film. So in this work, we deposit SiN x films using RF sputtering to prevent the effect of hydrogen ions and fabricate forming-free RRAM devices with reliable switching stability successfully. To solve the problems of forming-free devices mentioned above, we try to improve the quality of films by increasing deposit temperature. But with the In this study, forming-free and reliable resistive switching characteristics are demonstrated by using Pt doping in a stacked structure of SiN x resistive random access memory cells. Pt nanoparticles are embedded in situ and the size of them are about 1-2 nm. It ensures the potential of size scaling for the devices. Compared to those without Pt doping, a more reliable switching stability with better endurance and retention characteristics is obtained. The operating voltages and currents are low so that it is suitable for low power consumption applications. Films deposited at higher temperature show better compact...

Influence of Nitrogen Adsorption of Doped Ta on Characteristics of SiN_x‐Based Resistive Random Access Memory

Guo

Physica Status Solidi (a)

et al. 2019

Self Cite

The characteristics and conductive mechanism of Ta/SiN x /Ta:SiN x /SiN x /Pt resistive random access memory (RRAM) are investigated. Compared with Pt-doped devices with the same structure, the Ta-doped devices produce lower operation current in a high resistance state and a larger on/off radio. Furthermore, reliability tests show that the Ta-doped RRAM has good data retention ability and endurance. Ta clusters are observed in the Ta-doped SiN x layer through the transmission electron microscope. Also, the X-ray photoelectron spectra indicate that additional Si dangling bonds and tantalum nitride are present in the Ta-doped SiN x film. Based on the structure of the device, material analysis, and electrical characteristics, a model is proposed to explain the influence of the doped Ta on resistive switching behavior of the device.