Low-Power Switching of Nonvolatile Resistive Memory Using Hafnium Oxide

Abstract

Nonstoichiometric hafnium oxide (HfO x ) resistive-switching memory devices with low-power operation have been demonstrated. Polycrystalline HfO x (O : Hf ¼ 1:5 : 1) films with a thickness of 20 nm are grown on a titanium nitride (TiN) bottom electrode by commercial atomic layer deposition. Platinum (Pt) as a top electrode is used in the memory device. Voltage-induced resistance switching is repeatedly observed in the Pt/HfO x /TiN/Si memory device with resistance ratio is greater than 10. During the switching cycles, the power consumptions for high-and low-resistance states are found to be 0.25 and 0.15 mW, respectively. At 85 C, the memory device shows stable resistance switching and superior data retention with resistance ratio is greater than 100. In addition, our memory device shows little area dependence of resistance-switching behavior. The anodic electrode containing noble metal Pt serves an important role in maintaining stable resistance switching. The resistance switching in the HfO x films is thought to be due to the defects that are generated by the applied bias. The nonstoichiometric HfO x films are responsible for the low SET and RESET currents during switching. Our study shows that the HfO x resistive-switching memory is a promising candidate for next-generation nonvolatile memory device applications.

Switching by Ni Filaments in a HfO2 Matrix: A New Pathway to Improved Unipolar Switching RRAM

“…[10](b) and after 10 3 cycles in unipolar mode in Fig.[10](d)). To the best of our knowledge, the 10 3 cycle in unipolar mode is the best unipolar endurance data that was reported on HfO 2 -based RRAM system [4,5,6,7] . Fig.…”

“…[4] shows the forming behavior of 5nm HfO 2 film on Ni, NiPt and NiPtSi bottom electrodes. The forming here was done with positive bias to all these Ni-containing electrodes.…”

“…On the other hand, the unipolar switching properties of HfO 2 RRAM system are still poor. HfO 2 RRAM systems, which show unipolar switching, still suffer from low endurance (<500 cycles) [4,5,6,7] , and the essential usage of nonintegratable electrode materials like Pt or Au. However, as unipolar switching could potentially simplify the selector circuit, where one diode one RRAM (1D1R) structure can be used, instead of one transistor one RRAM (1T1R), unipolar switching devices are more promising for high-density nonvolatile memory application.…”

$\hbox{HfO}_{x}$ Bipolar Resistive Memory With Robust Endurance Using AlCu as Buffer Electrode

“…A 100-nm-thick bottom electrode TiN was deposited on an 8-in Si wafer by a sputtering system. A HfO 2 film with a thickness of 20 nm was then deposited by atomic layer deposition (ALD) [10]. A 6-nm-thick Al-Cu layer and a TiN top electrode were sequentially deposited on the HfO x layer by sputtering.…”

Improved Resistive Switching Properties of Solution-Processed TiOxFilm by Incorporating Atomic Layer Deposited TiO2layer

“…[1][2][3] In particular, ReRAM devices based on transition metal oxides (TMOs) such as NiO, 4) ZnO, 5) HfO 2 , 6) and TiO 2 , [7][8][9] have been proposed as strong candidates for reliable ReRAM device fabrication. Among them, TiO 2 is considered as one of the promising TMO materials, because of its stable resistive switching characteristics and relatively clear switching mechanism.…”