Resistive and New Optical Switching Memory Characteristics Using Thermally Grown Ge0.2Se0.8 Film in Cu/GeSex/W Structure

Abstract

It is known that conductive-bridge resistive-random-access-memory (CBRAM) device is very important for future high-density nonvolatile memory as well as logic application. Even though the CBRAM devices using different materials, structures, and switching performance have been reported in Nanoscale Res. Lett., 2015, however, optical switching characteristics by using thermally grown Ge0.2Se0.8 film in Cu/GeSex/W structure are reported for the first time in this study. The Cu/GeSex/W memory devices have low current compliances (CCs) ranging from 1 nA to 500 μA with low voltage of ±1.2 V, high resistance ratio of approximately 103, stable endurance of >200 cycles, and good data retention of >7 × 103 s at 85 °C. Multi-steps of RESET phenomena and evolution of Cu filaments’ shape under CCs ranging from 1 nA to 500 μA have been discussed. Under external white-light illumination with an intensity of 2.68 mW/cm2 (wavelength ranges from 390 to 700 nm), memory device shows optical switching with long read pulse endurance of >105 cycles. This CBRAM device has optically programmed and electrically erased, which can open up a new area of research field for future application.

Multilevel programming in Cu/NiOy/NiOx/Pt unipolar resistive switching devices

“…In order to overcome this, resistive random access memory (RRAM) devices are now emerging as some of the most promising candidates for next-generation memory applications [11,13,14,18,26,35,38]-though there exist several models for understanding the underlying mechanism [1,4,15,19,37]. Electrochemical-metallization-(ECM)based resistive switching (RS) [6,7,18,22,34,35] is considered to be the strongest contender, due to its easy backend-of-the-line (BEOL) processability with conventional CMOS technology using Cu as the active electrode [35]. However, the low solubility of Cu ions in metal oxide (MO) matrices is creating a bottleneck regarding the integration of metal-insulator-metal (MIM) devices.…”

Retention Model of TaO/HfO x and TaO/AlO x RRAM with Self-Rectifying Switch Characteristics

“…Those oxygen vacancies are recombined during the negative biasing reset process. Unlike filamentary-type RRAM, the HRS is always lower than the initial resistance state (IRS) after a reset operation [15–17]. To summarize, defect-trapping is a process that modulates vacancies through oxygen ion–vacancy recombination to control the resistance variation in the switching layer.…”

Impact of the Heat Conductivity of the Inert Electrode on ReRAM Performance and Endurance

“…A CBRAM device consists of an insulating/solid-state electrolyte layer sandwiched between an oxidizable active anode and an inert cathode. Different dielectric and semi-conductor materials have been investigated as solid electrolytes in CBRAM cells, such as GeSe, GeS 2 , WO 3 , ZnO 2 , Al 2 O 3 , Ta 2 O 5 or TaO x (6)(7)(8)(9). The active metal can be an oxidizing metal like Cu or Ag which has a relatively low work function of 5.1eV and 4.64eV, respectively, thus yielding ions readily (10).…”