Laser-Assisted Interface Engineering for Functional Interfacial Layer of Al/ZnO/Al Resistive Random Access Memory (RRAM)

Abstract

In oxide-based RRAMs using reactive electrodes such as Al, the properties of spontaneously formed interfacial layers are critical factors in determining the resistive switching (RS) performance and reliability. This interfacial layer can provide the beneficial function of oxygen reservoir and series resistance, but is very labile and prone to deterioration, causing fatal reliability problems. Moreover, there are technical difficulties in manipulating and improving the functional interfacial layer due to the various interaction dynamics near the interface and the unstable thermodynamic properties of Al. In this work, laser-assisted interface engineering, which allows exquisite manipulation of the labile interfacial layer, is proposed to improve the reliability and performance of Al/ZnO/Al RRAMs. In addition to photothermal and photochemical effects, the proposed laser process enables fine control over out-diffusions of Al atoms in the vicinity of the ZnO/Al interface, forming a robust interfacial layer with a uniform morphology and abundant oxygen Frenkel pairs. This laser-engineered interfacial layer increases the R HRS /R LRS ratio by over 100fold and reduces R HRS variation with improved oxygen reservoir ability. It also appears to reduce leakage current and power consumption by acting as a stable series resistance. The correlation between structural and stoichiometric properties of the functional interfacial layer and the performance and reliability of the RRAM is explicated. The results suggest that laser-assisted interface engineering can be one of the most promising methods to implement highly reliable, high-performance Al/ZnO/Al RRAMs.

A Review of Resistive Switching Devices: Performance Improvement, Characterization, and Applications

“…[ 122 ] Inserting an additional thin film between the RS layer and the electrode is a promising way to improve RS performance, such as power consumption, retention, uniformity, and ON/OFF ratio. [ 123 ] It can also suppress the leakage current in an RS device crossbar array. 2D material insertion, that is, graphene or MoS 2 , provides excellent impermeability, eliminating the penetration of CF atoms into the bottom electrode.…”

Configurable switching behavior in polymer-based resistive memories by adopting unique electrode/electrolyte arrangement

“…To further clarify the presence of AlO x layer and V O in the HRS of the device, the depth-proling XPS scans were also conducted on the Al/PMMA/Al device under pristine state. 54 Though, the O 1s spectra evidences almost similar peak proles in the entire depth-proling studies. The O i peak correspond to the Al-O bonding appeared to be similar from the surface to the interface.…”

“…Fig. 6c and d 54 However, the disappearing trend in Al 2p signal and the emerging trend in Ag 3d signal is observed beyond 600 s. The Ag 3d peak arises majorly because of the existence of pre-dissolved AgNP in the PMMA polymer matrix. Fig.…”

“…In particular, presence of oxygen atoms in the PMMA can able to react with the out-diffused Al atoms due to the higher oxygen concentration gradient in the interface and higher oxidation tendency of Al. 54,67 It is thus forms the AlO x layer under positive biasing and act as charge trap sites, demonstrating the SCLC mechanism. But, in the case of the Al/ AgNP-PMMA/Al device, the resistive switching arises by the electrochemical redox process of the pre-dissolved Ag nanoparticles (AgNP) in the PMMA matrix (Fig.…”

“…This is consistent with the insignicant composition of V O and AlO x layer available in the interfacial region under HRS of the pristine device. 54 To understand the inuence of Ag element on the PMMA device conguration, both AgNP included PMMA and Ag electrode included PMMA devices were also used for depth-proling XPS analysis. Fig.…”