Browsing by Author "Siang, Lew Wen"

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High-Performance TiN/Al2O3/ZnO/Al2O3/TiN Flexible RRAM Device With High Bending Condition
(2020-02-01)
Kumar, Dayanand
;
Chand, Umesh
;
Siang, Lew Wen
;
Tseng, Tseung-Yuen
;
電子工程學系及電子研究所
The bipolar resistive switching (RS) characteristics of the ZnO-based TiN/Al2O3/ZnO/Al2O3/TiN structure are investigated for flexible nonvolatile memory applications. Using a thin Al2O3 buffer layer on both sides of the ZnO device shows uniform and eminently stable bipolar resistance switching characteristics. The device exhibits good RS with more than two orders of resistance ON-OFF ratio, retention of 10(4) s at 120 C, good dc endurance 10(4) cycles, and high ac endurance of 10(8) cycles with 40-ns pulsewidth without any degradation. The device shows high mechanical stability when under 10(4) continuous repetitive flexible bendings, indicating that high endurance with a very small bending radius of up to 3 mm. The lower Gibbs free energy of the Al2O3 (-1676 kJ/mol) film compared with the ZnO (-320.4 kJ/mol) and TiO2 (-994 kJ/mol) films can improve the RS properties of the TiN/Al2O3/ZnO/Al2O3/TiN device. The significant improvement in the TiN/Al2O3/ZnO/Al2O3/TiN device is due to the reason that thin Al2O3 layers on both sides of ZnO would help stabilize the local oxygen migrations for the formation and rupture of the conductive filament during the continuous switching cycles, resulting in high memory switching characteristics.
ZrN-Based Flexible Resistive Switching Memory
(2020-05-01)
Kumar, Dayanand
;
Chand, Umesh
;
Siang, Lew Wen
;
Tseng, Tseung-Yuen
;
電子工程學系及電子研究所
In this letter, ZrN-based resistive random access memory (RRAM) is investigated for flexible memory applications for the near future. Due to the room-temperature fabrication process, the device is suitable for low-temperature flexible monolithic technologies. The TiN/ZrN/TiN device exhibits excellent AC endurance cycling (10(7)), a rapid speed (45 ns) and stable retention (10(4) s) at 100 degrees C without any degradation. In addition, RRAM devices built with an additional HfN interface layer exhibit small operational voltage variations and stable switching characteristics. The flexibility of the device is excellent, and it maintains excellent electrical characteristics at a bending radius of up to 4 mm.