Enhanced switching stability in Ta2O5 resistive RAM by fluorine doping

Abstract

The effect of fluorine doping on the switching stability of Ta2O5 resistive random access memory devices is investigated. It shows that the dopant serves to increase the memory window and improve the stability of the resistive states due to the neutralization of oxygen vacancies. The ability to alter the current in the low resistance state with set current compliance coupled with large memory window makes multilevel cell switching more favorable. The devices have set and reset voltages of <1 V with improved stability due to the fluorine doping. Density functional modeling shows that the incorporation of fluorine dopant atoms at the two-fold O vacancy site in the oxide network removes the defect state in the mid bandgap, lowering the overall density of defects capable of forming conductive filaments. This reduces the probability of forming alternative conducting paths and hence improves the current stability in the low resistance states. The doped devices exhibit more stable resistive states in both dc and pulsed set and reset cycles. The retention failure time is estimated to be a minimum of 2 years for F-doped devices measured by temperature accelerated and stress voltage accelerated retention failure methods.

Sputtering-deposited amorphous SrVOx-based memristor for use in neuromorphic computing

“…2(a). The I-V characteristics during the voltage sweeps are indicative of typical bipolar resistive switching behavior [15][16][17][18][19][20] . After the electroforming process, DC voltage sweeping from 0 V → 1 V → 0 V with an I CC of 1 mA resulted in a SET process (i.e., an off-to-on transition) and sweeping from 0 V → −0.7 V → 0 V without an I CC led to a RESET process (i.e., an on-to-off transition).…”

“…This type of multilevel resistance allows the possibility of multilevel storage, which can provide more storage space within a single cell and generate synaptic behavior, leading to material and structural innovation [11][12][13][14] . Thus, researchers have made an effort to realize multilevel storage using a variety of approaches, including heterostructures 15,16 , the insertion of an interlayer 17,18 , and doping techniques 19,20 .…”

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

“…Sedghi et al fabricated a N‐doped Ti/Ta 2 O 5 /Pt device through atomic layer deposition (ALD), in which H 2 O was substituted by NH 4 OH solution. [ 118 ] During the formation of the CFs, N dopants capture the excess electrons introduced by the formation of oxygen vacancies, thus eliminating the alternative conductive paths, and reduce the number of weak CFs, improving the stability and reducing the HRS current. Li and Su prepared Cr‐doped ZnO as an RS layer to improve device performance.…”

Annealing atmosphere effect on the resistive switching and magnetic properties of spinel Co3O4 thin films prepared by a sol–gel technique

“…1 The observed RS behaviors can be classied as bipolar, unipolar, complementary, and threshold switching. 1,4,5 In recent years, a variety of metal oxides such as RS active layers have been demonstrated to show the RS effect such as binary oxides HfO 2 , ZnO, Ta 2 O 5 , [6][7][8] ternary oxides BiFeO 3 , CaTiO 3 , and ferrite materials. 3,9,10 along with complex oxides Ba 0.6 Sr 0.4 TiO 3 , PrBa 2 -Cu 3 O x , and La 0.3 Pr 0.4 Ca 0.3 MnO 3 .…”