High performance of graphene oxide-doped silicon oxide-based resistance random access memory
- Rui Zhang1,
- Kuan-Chang Chang2,
- Ting-Chang Chang3, 4Email author,
- Tsung-Ming Tsai2,
- Kai-Huang Chen5,
- Jen-Chung Lou1,
- Jung-Hui Chen6Email author,
- Tai-Fa Young7,
- Chih-Cheng Shih2,
- Ya-Liang Yang2, 7,
- Yin-Chih Pan2,
- Tian-Jian Chu2,
- Syuan-Yong Huang2,
- Chih-Hung Pan2,
- Yu-Ting Su3,
- Yong-En Syu3 and
- Simon M Sze8
© Zhang et al.; licensee Springer. 2013
Received: 22 August 2013
Accepted: 11 October 2013
Published: 21 November 2013
In this letter, a double active layer (Zr:SiO x /C:SiO x ) resistive switching memory device with outstanding performance is presented. Through current fitting, hopping conduction mechanism is found in both high-resistance state (HRS) and low-resistance state (LRS) of double active layer RRAM devices. By analyzing Raman and FTIR spectra, we observed that graphene oxide exists in C:SiO x layer. Compared with single Zr:SiO x layer structure, Zr:SiO x /C:SiO x structure has superior performance, including low operating current, improved uniformity in both set and reset processes, and satisfactory endurance characteristics, all of which are attributed to the double-layer structure and the existence of graphene oxide flakes formed by the sputter process.
KeywordsHigh performance Graphene oxide RRAM Hopping conduction
Recently, the applications of mobile electronic products, such as combined display designs[1–9], memories[10–12], and logic ICs, have popularized considerably. With the growing demand of powerful mobile electronic products, non-volatile memory (NVM) has been widely applied due to its low power consumption requirements. To surmount the technical and physical limitation issues of conventional charge storage-based memories[13–17], the resistance random access memory (RRAM) is a kind of promising NVM due to its superior characteristics such as low cost, simple structure, high-speed operation, non-destructive readout, and the compatibility in the semiconductor industry[18–39].
Graphene and graphene oxide-based materials attract vast attention and have been applied into various fields. Graphene oxide (GO) is a material of great interest for its special quality, and its electrical properties can be modified by altering the attached chemical groups. It exhibits resistance switching behaviors by adding and removing oxygen-containing groups, which are quite different from common filament dominant resistance switching[41–44].
In our research, double resistive switching layer RRAM with a sandwiched structure of Pt/Zr:SiO x /C:SiO x /TiN was fabricated to investigate the switching merits by inserting C:SiO x layer. Graphene oxide was observed in the inserted layer from the analysis of Raman and Fourier transform infrared (FTIR) spectra. Meanwhile, single resistive switching layer devices (Pt/Zr:SiO x /TiN) were also fabricated so as to make a comparison. Through current fitting, hopping conduction mechanism was found in both high-resistance state (HRS) and low-resistance state (LRS) of Zr:SiO x /C:SiO x RRAM devices. The resistance switching properties of graphene oxide was different from unstable metal filament formation and rupture[45, 46]. The performance of RRAM devices has always been one of the targets which influence its mass production and wide application in the semiconductor industry. This is also the reason why the performance of Zr:SiO x /GO:SiO x stacking structure is focused and analyzed in detail in this paper owing to its superior properties from various aspects.
The experimental specimens were prepared as follows: for the single active layer specimen, the Zr:SiO x thin film (about 20 nm) was deposited on the TiN/Ti/SiO2/Si substrate by co-sputtering with the pure SiO2 and Zr targets. The active layer was deposited onto patterned TiN bottom electrode, and the sputtering power was fixed at RF power 200 and 20 W for SiO2 and Zr targets, respectively. The co-sputtering was executed in argon ambient (Ar = 30 sccm) with a working pressure of 6 mTorr at room temperature. However, for the double resistive switching layer specimen, first a C:SiO x film (about 6 nm) was deposited by co-sputtering with the SiO2 and C targets. The sputtering power was fixed at RF power 200 and 5 W for SiO2 and C targets, respectively. The co-sputtering was also executed in argon ambient (Ar = 30 sccm) with a working pressure of 6 mTorr at room temperature. Then, the layer of Zr:SiO x (about 14 nm) was deposited with the same RF power, argon ambient, and working pressure as antecedent single Zr:SiO x layer specimen.
Ultimately, the Pt top electrode of 200-nm thickness was deposited on both specimens by direct current (DC) magnetron sputtering. The entire electrical measurements of devices with the Pt electrode of 250-μm diameter were performed using Agilent B1500 semiconductor parameter analyzer (Santa Clara, CA, USA). Besides, X-ray photoelectron spectroscopy (XPS), FTIR, and Raman spectroscopy were used to analyze the mole fraction, chemical composition, and bonding of these insulator materials, respectively.
Results and discussion
The resistive switching mechanism in Zr:SiO x can be explained by the stochastic formation and rupture of conduction filaments. This is also the reason why we can find Ohmic conduction mechanism in LRS and Pool-Frenkel conduction mechanism in HRS. As in LRS, electrons conduct through metal filaments from the top electrode to the bottom electrode, and in HRS, electrons conduct through shallow defects between the tip of ruptured filament and the bottom TiN electrode. Due to the stochastic formation of conduction filament process, single active layer RRAM device exhibits less stable set voltage and lower degree of uniformity in the reset process.
Comparatively, the C:SiO x film works as the switching layer, in which the carrier will hop through the carbon atoms within the carbocycle. If the bottom TiN electrode is applied with a negative bias, oxygen atoms are repelled to the reverse direction of TiN electrode and adsorbed by graphene oxide. With the adsorption of oxygen atoms, carbon-carbon bonds are stretched and carbocycle is enlarged, which results in longer hopping distance of carriers. The adsorption and desorption of oxygen-containing groups are responsible for the resistive switching in graphene oxide-doped silicon RRAM[41–44]. Compared with random formation of conduction filament process, adsorption and desorption of oxygen-containing groups are more stable, as the movement of oxygen-containing groups is much more directional (to graphene oxide). Meanwhile, conduction path always exists, and the difference is hopping distance variation and oxidation rate of graphene oxide. At the top Zr:SiO2 layer, the metal filament serves as the conduction way and has the ability of concentrating the electrical field, which facilitates the adsorption and desorption processes of oxygen chemical groups.
In conclusion, by co-sputtering C and Zr with SiO2, respectively, we fabricated a double resistive switching layer RRAM, which has significantly outstanding performance. Both FTIR and Raman spectra confirm the existence of graphene oxide in the switching layer of double active layer RRAM devices. Compared with the stochastic formation of conducting filaments, the adsorption and desorption of oxygen atoms from carbocycle work much more stable. This is also the reason why Zr:SiO x /C:SiO x structure has superior switching performance and higher stability.
This work was performed at the National Science Council Core Facilities Laboratory for Nano-Science and Nano-Technology in the Kaohsiung-Pingtung area and was supported by the National Science Council of the Republic of China under contract nos. NSC-102-2120-M-110-001, and NSC 101-2221-E-110-044-MY3.
- Nomura K, Ohta H, Takagi A, Kamiya T, Hirano M, Hosono H: Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors. Nature 2004, 432: 488. 10.1038/nature03090View ArticleGoogle Scholar
- Tsai CT, Chang TC, Chen SC, Lo I, Tsao SW, Hung MC, Chang JJ, Wu CY, Huang CY: Influence of positive bias stress on N2O plasma improved InGaZnO thin film transistor. Appl Phys Lett 2010, 96: 242105. 10.1063/1.3453870View ArticleGoogle Scholar
- Chen TC, Chang TC, Tsai CT, Hsieh TY, Chen SC, Lin CS, Hung MC, Tu CH, Chang JJ, Chen PL: Behaviors of InGaZnO thin film transistor under illuminated positive gate-bias stress. Appl Phys Lett 2010, 97: 112104. 10.1063/1.3481676View ArticleGoogle Scholar
- Yabuta H, Sano M, Abe K, Aiba T, Den T, Kumomi H: High-mobility thin-film transistor with amorphous InGaZnO4 channel fabricated by room temperature rf-magnetron sputtering. Appl Phys Lett 2006, 89: 112123. 10.1063/1.2353811View ArticleGoogle Scholar
- Chen TC, Chang TC, Hsieh TY, Lu WS, Jian FY, Tsai CT, Huang SY, Lin CS: Investigating the degradation behavior caused by charge trapping effect under DC and AC gate-bias stress for InGaZnO thin film transistor. Appl Phys Lett 2011, 99: 022104. 10.1063/1.3609873View ArticleGoogle Scholar
- Chung WF, Chang TC, Li HW, Chen SC, Chen YC, Tseng TY, Tai YH: Environment-dependent thermal instability of sol–gel derived amorphous indium-gallium-zinc-oxide thin film transistors. Appl Phys Lett 2011, 98: 152109. 10.1063/1.3580614View ArticleGoogle Scholar
- Jeong S, Ha YG, Moon J, Facchetti A, Marks TJ: Role of gallium doping in dramatically lowering amorphous-oxide processing temperatures for solution-derived indium zinc oxide thin-film transistors. Adv Mater 2010, 22: 1346–1350. 10.1002/adma.200902450View ArticleGoogle Scholar
- Tsao SW, Chang TC, Huang SY, Chen MC, Chen SC, Tsai CT, Kuo YJ, Chen YC, Wu WC: Hydrogen-induced improvements in electrical characteristics of a-IGZO thin-film transistors. Solid State Electron 2010, 54: 1497–1499. 10.1016/j.sse.2010.08.001View ArticleGoogle Scholar
- Chen TC, Chang TC, Hsieh TY, Tsai CT, Chen SC, Lin CS, Hung MC, Tu CH, Chang JJ, Chen PL: Light-induced instability of an InGaZnO thin film transistor with and without SiOx passivation layer formed by plasma-enhanced-chemical-vapor-deposition. Appl Phys Lett 2010, 97: 192103. 10.1063/1.3514251View ArticleGoogle Scholar
- Chen WR, Chang TC, Yeh JL, Sze SM, Chang CY: Reliability characteristics of NiSi nanocrystals embedded in oxide and nitride layers for nonvolatile memory application. Appl Phys Lett 2008, 92: 152114. 10.1063/1.2905812View ArticleGoogle Scholar
- Yeh PH, Chen LJ, Liu PT, Wang DY, Chang TC: Metal nanocrystals as charge storage nodes for nonvolatile memory devices. Electrochim Acta 2007, 52: 2920–2926. 10.1016/j.electacta.2006.09.006View ArticleGoogle Scholar
- Jiang DD, Zhang MH, Huo ZL, Wang Q, Liu J, Yu ZA, Yang XN, Wang Y, Zhang B, Chen JN, Liu M: A study of cycling induced degradation mechanisms in Si nanocrystal memory devices. Nanotechnology 2011, 22: 254009. 10.1088/0957-4484/22/25/254009View ArticleGoogle Scholar
- Pavan P, Bez R, Olivo P, Zanoni E: Flash memory cells - an overview. Proc IEEE 1997, 85: 8.View ArticleGoogle Scholar
- Bu J, White MH: Design considerations in scaled SONOS nonvolatile memory devices. Solid State Electron 2001, 45: 1.View ArticleGoogle Scholar
- Chang TC, Jian FY, Chen SC, Tsai YT: Developments in nanocrystal memory. Mater Today 2011, 14: 608. 10.1016/S1369-7021(11)70302-9View ArticleGoogle Scholar
- Zhen L, Guan W, Shang L, Liu M, Liu G: Organic thin-film transistor memory with gold nanocrystals embedded in polyimide gate dielectric. J Phys D Appl Phys 2008, 41: 135111. 10.1088/0022-3727/41/13/135111View ArticleGoogle Scholar
- Tsai YT, Chang TC, Lin CC, Chen SC, Chen CW, Sze SM, Yeh FS, Tseng TY: Influence of nanocrystals on resistive switching characteristic in binary metal oxides memory devices. Electrochem Solid-State Lett 2011, 14: H135-H138. 10.1149/1.3531843View ArticleGoogle Scholar
- Guan WH, Long SB, Jia R, Liu M: Nonvolatile resistive switching memory utilizing gold nanocrystals embedded in zirconium oxide. Appl Phys Lett 2007, 91: 062111. 10.1063/1.2760156View ArticleGoogle Scholar
- Liu Q, Guan WH, Long SB, Jia R, Liu M, Chen JN: Resistive switching memory effect of ZrO2 films with Zr+ implanted. Appl Phys Lett 2008, 92: 012117. 10.1063/1.2832660View ArticleGoogle Scholar
- Syu YE, Chang TC, Tsai TM, Hung YC, Chang KC, Tsai MJ, Kao MJ, Sze SM: Redox reaction switching mechanism in RRAM device with Pt/CoSiOX/TiN structure. IEEE Electron Device Lett 2011, 32: 545.View ArticleGoogle Scholar
- Tsai TM, Chang KC, Chang TC, Chang GW, Syu YE, Su YT, Liu GR, Liao KH, Chen MC, Huang HC, Tai YH, Gan DS, Sze SM: Origin of hopping conduction in Sn-doped silicon oxide RRAM with supercritical CO2 fluid treatment. IEEE Electron Device Lett 2012, 33: 1693.View ArticleGoogle Scholar
- Tsai TM, Chang KC, Chang TC, Syu YE, Chuang SL, Chang GW, Liu GR, Chen MC, Huang HC, Liu SK, Tai YH, Gan DS, Yang YL, Young TF, Tseng BH, Chen KH, Tsai MJ, Ye C, Wang H, Sze SM: Bipolar resistive RAM characteristics induced by nickel incorporated into silicon oxide dielectrics for IC applications. IEEE Electron Device Lett 2012, 33: 1696.View ArticleGoogle Scholar
- Chen MC, Chang TC, Tsai CT, Huang SY, Chen SC, Hu CW, Sze SM, Tsai MJ: Influence of electrode material on the resistive memory switching property of indium gallium zinc oxide thin films. Appl Phys Lett 2010, 96: 262110. 10.1063/1.3456379View ArticleGoogle Scholar
- Syu YE, Chang TC, Lou JH, Tsai TM, Chang KC, Tsai MJ, Wang YL, Liu M, Simon M, Sze SM: Atomic-level quantized reaction of HfOx memristor. Appl Phys Lett 2013, 102: 172903. 10.1063/1.4802821View ArticleGoogle Scholar
- Liu M, Abid Z, Wang W, He XL, Liu Q, Guan WH: Multilevel resistive switching with ionic and metallic filaments. Appl Phys Lett 2009, 94: 233106. 10.1063/1.3151822View ArticleGoogle Scholar
- Chang KC, Tsai TM, Chang TC, Wu HH, Chen JH, Syu YE, Chang GW, Chu TJ, Liu GR, Su YT, Chen MC, Pan JH, Chen JY, Tung CW, Huang HC, Tai YH, Gan DS, Sze SM: Characteristics and mechanisms of silicon-oxide-based resistance random access memory. IEEE Electron Device Lett 2013, 34: 399–401.View ArticleGoogle Scholar
- Li YT, Long SB, Zhang MH, Liu Q, Zhang S, Wang Y, Zuo QY, Liu S, Liu M: Resistive switching properties of Au/ZrO2/Ag structure for low voltage nonvolatile memory applications. IEEE Electron Device Lett 2010, 31: 117–119.View ArticleGoogle Scholar
- Chang KC, Pan CH, Chang TC, Tsai TM, Zhang R, Lou JC, Young TF, Chen JH, Shih CC, Chu TJ, Chen JY, Su YT, Jiang JP, Chen KH, Huang HC, Syu YE, Gan DS, Sze SM: Hopping effect of hydrogen-doped silicon oxide insert RRAM by supercritical CO2 fluid treatment. IEEE Electron Device Lett 2013, 34: 617–619.View ArticleGoogle Scholar
- Chang KC, Tsai TM, Chang TC, Wu HH, Chen KH, Chen JH, Young TF, Chu TJ, Chen JY, Pan CH, Su YT, Syu YE, Tung CW, Chang GW, Chen MC, Huang HC, Tai YH, Gan DS, Wu JJ, Hu Y, Sze SM: Low temperature improvement method on Zn:SiOx resistive random access memory devices. IEEE Electron Device Lett 2013, 34: 511–513.View ArticleGoogle Scholar
- Syu YE, Chang TC, Tsai TM, Chang GW, Chang KC, Lou JH, Tai YH, Tsai MJ, Wang YL, Sze SM: Asymmetric carrier conduction mechanism by tip electric field in WSiOx resistance switching device. IEEE Electron Device Lett 2012, 33(3):342–344.View ArticleGoogle Scholar
- Chang KC, Tsai TM, Zhang R, Chang TC, Chen KH, Chen JH, Young TF, Lou JC, Chu TJ, Shih CC, Pan JH, Su YT, Tung CW, Chen MC, Wu JJ, Hu Y, Sze SM: Electrical conduction mechanism of Zn:SiOx resistance random access memory with supercritical CO2 fluid process. Appl Phys Lett 2013, 103: 083509. 10.1063/1.4819162View ArticleGoogle Scholar
- Chang KC, Zhang R, Chang TC, Tsai TM, Lou JC, Chen JH, Young TF, Chen MC, Yang YL, Pan YC, Chang GW, Chu TJ, Shih CC, Chen JY, Pan CH, Su YT, Syu YE, Tai YH, Sze SM: Origin of hopping conduction in graphene-oxide-doped silicon oxide resistance random access memory devices. IEEE Electron Device Lett 2013, 34(5):677–679.View ArticleGoogle Scholar
- Tsai TM, Chang KC, Chang TC, Syu YE, Liao KH, Tseng BH, Sze SM: Dehydroxyl effect of Sn-doped silicon oxide resistance random access memory with supercritical CO2 fluid treatment. Appl Phys Lett 2012, 101: 112906. 10.1063/1.4750235View ArticleGoogle Scholar
- Chang KC, Tsai TM, Chang TC, Syu YE, Liao KH, Chuang SL, Li CH, Gan DS, Sze SM: The effect of silicon oxide based RRAM with tin doping. Electrochem Solid-State Lett 2012, 15(3):H65-H68. 10.1149/2.013203eslView ArticleGoogle Scholar
- Chang KC, Tsai TM, Chang TC, Syu YE, Wang C-C, Liu SK, Chuang SL, Li CH, Gan DS, Sze SM: Reducing operation current of Ni-doped silicon oxide resistance random access memory by supercritical CO2 fluid treatment. Appl Phys Lett 2011, 99(26):263501. 10.1063/1.3671991View ArticleGoogle Scholar
- Syu YE, Chang TC, Tsai CT, Chang GW, Tsai TM, Chang KC, Tai YH, Tsai MJ, Sze SM: Improving Resistance Switching Characteristics with SiGeOx/SiGeON Double Layer for Nonvolatile Memory Applications. Electrochem Solid-State Lett 2012, 14(10):H419-H421.View ArticleGoogle Scholar
- Syu YE, Chang TC, Tsai TM, Chang GW, Chang KC, Tai YH, Tsai MJ, Wang YL, Sze SM: Silicon introduced effect on resistive switching characteristics of WOX thin films. Appl Phys Lett 2012, 100: 022904. 10.1063/1.3676194View ArticleGoogle Scholar
- Tsai TM, Chang KC, Zhang R, Chang TC, Lou JC, Chen JH, Young TF, Tseng BH, Shih CC, Pan YC, Chen MC, Pan JH, Syu YE, Sze SM: Performance and characteristics of double layer porous silicon oxide resistance random access memory. Appl Phys Lett 2013, 102(25):253509. 10.1063/1.4812474View ArticleGoogle Scholar
- Su YT, Chang KC, Chang TC, Tsai TM, Zhang R, Lou JC, Chen JH, Young TF, Chen KH, Tseng BH, Shih CC, Yang YL, Chen MC, Chu TJ, Pan CH, Syu YE, Sze SM: Characteristics of hafnium oxide resistance random access memory with different setting compliance current. Appl Phys Lett 2013, 103(16):163502. 10.1063/1.4825104View ArticleGoogle Scholar
- Geim AK, Novoselov KS: The rise of grapheme. Nature Mater 2007, 6: 3.View ArticleGoogle Scholar
- Dreyer DR, Park S, Bielawski CW, Ruoff RS: The chemistry of graphene oxide. Chem Soc Rev 2010, 39: 1.View ArticleGoogle Scholar
- Zhuge F, Hu B, He C, Zhou X, Liu Z, Li R: Mechanism of nonvolatile resistive switching in graphene oxide thin films. Carbon 2011, 49: 12.View ArticleGoogle Scholar
- Liao SH, Liu PL, Hsiao MC, Teng CC, Wang CA, Ger MD, Chiang CL: One-step reduction and functionalization of graphene oxide with phosphorus-based compound to produce flame-retardant epoxy nanocomposite. Ind Eng Chem Res 2012, 51: 12.Google Scholar
- Jug K: A bond order approach to ring current and aromaticity. J Org Chem 1983, 48: 8. 10.1021/jo00149a003View ArticleGoogle Scholar
- Li Y, Long S, Hangbing L, Liu Q, Wang W, Wang Q, Huo Z, Wang Y, Zhang S, Liu S, Liu M: Reset instability in Cu/ZrO2:Cu/Pt RRAM device. IEEE Electron Device Lett 2011, 32: 3.View ArticleGoogle Scholar
- Guan W, Long S, Liu Q, Liu M, Wang W: Nonpolar nonvolatile resistive switching in Cu doped ZrO2. IEEE Electron Devices Lett 2008, 29: 5.Google Scholar
- Chen D, Feng H, Li J: Graphene oxide: preparation, functionalization, and electrochemical applications. Chem Rev 2012, 112: 11.Google Scholar
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.