The integrated vertically-coupled resistive random-access memory (ReRAM) based microdisk resonator and the relevant performance evaluation

摘要

The integration of the transparent ITO/NiO/ITO Resistive Random-Access Memory (ReRAM) with vertically-coupled buswaveguides, which is ultimately emerged as a ReRAM-based microdisk resonator fabricated on lithium niobate (LiNbO3)substrate, is successfully realized. The transparent ITO and NiO layers are deposited by radio-frequency sputteringtechnique, while the bus waveguides in LiNbO3 is achieved by a proton-exchange method. The ReRAM-based microdiskresonator thus designed and fabricated have dual functionality of memory and optical spectral filtering capabilities. Whenthe ReRAM microdisk resonator is electronically set at different memory states, that is, ReRAM is alternatively set inhigh-resistance state (HRS) and low-resistance state (LRS), the corresponding spectral shifts detected at both through anddrop ports are noticeable different, when compared with those obtained before and after subjecting the ReRAM to arequired forming process. Specifically, the spectral shift associated with the LRS state of ReRAM between the throughand drop port terminal is around 4.4 nm, as compared to the spectral shift of approximately 1.7 nm that is associated withthe HRS state of ReRAM between the same two terminals. The aforementioned characteristics of selective light wavefiltering can be selectively tuned by varying the ReRAM device dimensions. The adoption of the different thin-filmmaterials for the ReRAM fabrication may also play an important role in spectral tuning. Most important of all, because ofdifferent spectral shifts observed, the particular memory state of ReRAM could possibly and uniquely be interrogated byan optical means. The resultant discovery opens a new pathway in the future to the realization of one of the new opticalmemory devices.