1 02 Zn-doped Silicon Dioxide Resistance Random Access Memory 1 2 2 2 1 3 4 1 2 3 4 Resistance Random Access Memory : RRAM RRAM SiO 2 IC SiO 2 SiO 2 SiO 2 IC IC Abstract Among the next-generation memory devices, resistance random access memory (RRAM) is a promising candidate for the applications on digital storage system due to its simple cell structure, low power consumption, high operating speed, and nondestructive readout. Therefore, the research of RRAM devices is a hot topic in the academia. Because the underlying mechanism of resistive switching behavior is still not understood clearly, many researches of RRAM focus on the physical models of resistive switching behaviors and its reliability and feasibility of nonvolatile memory properties for various
NANO COMMUNICATION 20 No.1 03 materials. Silicon dioxide is a promising material for integrated circuits (IC) process due to its great chemical stability. In thisstudy, although the pure SiO 2 material didn t reveal the resistive switching behaviors, the bipolar switching characteristics of silicon based material can be obtained through light metal doped in the SiO2 by co-sputtering technology. Therefore, the research using silicon-based oxide as the resistance-switching layer was worthy of investigation due to its high compatibility in IC fabrication for semiconductor industries. In addition, we proposed a novel supercritical CO 2 fluid (SCCO 2 ) treatment method on the silicon based Zn-doped (Zn:SiO 2 ) RRAM for the application in back-end of line (BEOL) of IC process. It was found that the operation current of Zn:SiO 2 RRAM can be reduced to decrease the power consumption and heating degradation of RRAM devices through the SCCO 2 treatment technology. We believe that the method is useful to raise device density of IC product. Keywords RRAMSiO 2 RRAM Nonvolatile Silicon Oxide Resistive Switching SCCO 2 PCRAM RRAM RRAM ns DRAM SRAM Flash 3C Volatile Non-volatile μa Retention Endurance RRAM Metal-Insulator-Metal MIM RRAM RRAM DRAM Flash Flash Flash DRAM DRAM FeRAM MRAM Memory Non-volatile Memory, NVM
1 04 SRAM DRAM Flash Read Only Memory, ROM Flash Floating gate Flash MP3 USB Endurance [1] 1T1R 1D1R MIM 1D1R [2-6] SiO 2 - based RRAM MIM SiO 2 CMOS RRAM COMS RRAM [7-9] SiO 2 600 COMS Multi-target Sputter Metal-doped SiO 2 Thin-film Supercritical CO 2 Fluid, SCCO 2 3.1 Filament RRAM 1 FTIR XPS 2 2 RRAM 2 3 Endurance > 10 7, Retentio > 10 4 RRAM
NANO COMMUNICATION 20 No.1 05 RRAM 4 Poole-frenkel 5 1 FTIR Zn SiO x XPS Zn 2
1 06 [10] 3.2 Supercritical CO 2 Fluid, SCCO 2 RRAM IC 3 Endurance R H / R L = 10 10 7 Retention R H / R L >10 10 4 4
NANO COMMUNICATION 20 No.1 07 5 Pt / Zn:SiO x / TiN RRAM 400 o C 120 o C 6 TEM [11] Thermal Budget HfOx 120 6 TEM
1 08 Threshold Voltage on Current Sub-threshold Slope [12] HfOx Traps [13] 7 8(a) RRAM 8(a) HRS Poole-frenkel Schottky 8(b) 9 RRAM LRS Ohmic Conduction 9 (c) Hopping Conduction 3-9 (b) 10 FTIR [14] 7 HfOx 8 SCCO 2 RRAM HRS LRS HRS Poole-frenkel Schottky
NANO COMMUNICATION 20 No.1 09 SiO 2 RRAM RRAM RRAM [15-18] NSC 100-2120-M- 110-003 NSC 100-2221-E-110-060 9 SCCO 2 RRAM LRS Ohmic Hopping 10 (a) SCCO 2 FTIR (b) SCCO 2 Si-O-Zn (c) SCCO 2 Si-O-Si
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