TY  - JOUR
AU  - Kim, W.
AU  - Menzel, S.
AU  - Wouters, D. J.
AU  - Waser, R.
AU  - Rana, V.
TI  - 3-Bit Multilevel Switching by Deep Reset Phenomenon in Pt/W/TaO$_{X}$ /Pt-ReRAM Devices
JO  - IEEE electron device letters
VL  - 37
IS  - 5
SN  - 1558-0563
CY  - New York, NY
PB  - IEEE
M1  - FZJ-2016-07037
SP  - 564 - 567
PY  - 2016
AB  - The influence of two different ohmic electrodes (W and Ta) on the resistive switching characteristics of TaOx-based resistive random access memory (ReRAM) devices has been studied. Consistently, higher resistance OFF states have been observed with the W-ohmic electrode under the same operational conditions for all reset stop voltages (Vreset-stop) during both the dc and ac measurements. The deeper reset for samples with W-electrode is attributed to the less negative Gibbs-free energy of W-oxide compared with Ta-oxide, resulting in easier re-oxidation of the filament through oxygen exchange with the W-electrode. The higher ROFF/RON(>103) with the W-electrode enables 3-bit multilevel cell operation in the Pt/W/TaOx/Pt ReRAM device. An excellent retention for these eight states is demonstrated at 125°C for 104 s. Furthermore, the TaOx ReRAM device with both the electrodes shows high endurance up to 106 cycles based on two states.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000374868300010
DO  - DOI:10.1109/LED.2016.2542879
UR  - https://juser.fz-juelich.de/record/824448
ER  -