Switching Mode and Mechanism in Binary Oxide Resistive Random Access Memory Using Ni Electrode

Abstract

Resistive-switching (RS) modes in different CMOS-compatible binary oxides have been shown to be governed by the interplay with the Ni top electrode. Unipolar RS and metallic low-resistance state in polycrystalline HfO 2 and ZrO 2 are distinct from the preferential bipolar RS and semiconductive low-resistance state in amorphous Al 2 O 3 and SiO 2 . Backside secondary ion mass spectrometry (SIMS) has shown the formation of Ni filaments in HfO 2 , in contrast to the formation of oxygen-vacancy filaments in Al 2 O 3 . The differences have been explained by strong dependence of Ni migration on the oxide crystallinity. Additionally, the RS mode can be further tailored using bilayer structures. The oxide layer next to the Si bottom electrode and its tendency of forming Ni filaments play significant roles in unipolar RS in the bilayer structures, in support of the conical-shape Ni filament model where the connecting and rupture of filaments for unipolar RS occur at the smallest diameter near the bottom electrodes. #

Analysis of the Switching Variability in <inline-formula> <tex-math notation="TeX">$\hbox{Ni/HfO}_{2}$</tex-math></inline-formula>-Based RRAM Devices

“…RESULTS AND DISCUSSION Fig. 1(b) shows typical unipolar switching behavior [3], [4], [10], [11] for the studied Ni/HfO 2 -based resistive switching structures. It is interesting to note that significant variability of the LRS current levels (I on ) is observed [see Fig.…”

“…This is because filamentary RRAM have shown excellent characteristics in terms of fast operation speed, low power consumption, high scalability, and high density 3-D integration. Among a wide range of transition metal oxides, HfO 2 presents excellent switching properties [2], [3]. The main factor behind the resistive switching phenomenon is the formation and rupture of a conductive filament (CF) path constructed by oxygen vacancies or metallic atoms.…”

The Future of Memristors: Materials Engineering and Neural Networks

“…For example, for the HfO 2 RS layer, the application of different electrodes may change the switching performance of the memristor and even the RS mode. [ 92,93 ]…”

Electrical Contact Formation in Micro Four‐Point Probe Measurements

“…Indeed, filament‐based switching behavior has been observed in similar material stacks, that is, Ni–SiO 2 –Si. Such a process could also explain why R 1 breaks down first, as the filament formation is favored when a positive field is applied from the metal toward the semiconductor. The electric field is indeed not symmetric for both electrodes as it points into the sample under electrode 1 and out of the sample under electrode 2 (red arrows in Figure a) .…”