Investigation of resistive switching in Cu-doped HfO₂thin film for multilevel non-volatile memory applications

Abstract

In this paper, the resistive switching characteristics in a Cu/HfO(2):Cu/Pt sandwiched structure is investigated for multilevel non-volatile memory applications. The device shows excellent resistive switching performance, including good endurance, long retention time, fast operation speed and a large storage window (R(OFF)/R(ON)>10(7)). Based on the temperature-dependent test results, the formation of Cu conducting filaments is believed to be the reason for the resistance switching from the OFF state to the ON state. By integrating the resistive switching mechanism study and the device fabrication, different resistance values are achieved using different compliance currents in the program process. These resistance values can be easily distinguished in a large temperature range, and can be maintained over 10 years by extrapolating retention data at room temperature. The integrated experiment and mechanism studies set up the foundation for the development of high-performance multilevel RRAM.

Demonstration and modeling of multi-bit resistance random access memory

“…1 RRAM can also exhibit >2 resistance states that may promise multi-bit storage. [2][3][4][5][6][7][8] In principle, if each single cell can display 2 N distinguished states, then for the same storage capacity the required die area will scale with 1/N. Stated alternatively, for the same die area, each 2 N -state layer of a 2D memory has the same storage capacity of N 2-state layers of a 3D memory.…”

“…In the literature, multilevel states of RRAM are usually revealed by imposing a current compliance 3,4 or through voltage programming. 2,7 The fact that these approaches seem to be applicable to all types of RRAM, irrespective of their underlying switching/conduction mechanisms, suggests a common understanding of their existence and control may be possible.…”

Multilevel resistance in ZnO nanowire memristors enabled by hydrogen annealing treatment

“…Finally, at sufficiently high voltage (region III), where the electrons fully occupy trap sites, an abrupt surge of current is observed, similar to the formation phenomena reported in numerous resistive switching devices. [4][5][6][7][11][12][13][14][31][32][33][34][36][37][38][39][40][41][42][43][44][45] In the present system, this abrupt turn-on is likely associated with a large local concentration of oxygen vacancies or to the development of a conducting metal (Zn) filaments with the a-ZnO layer. 33 To test the model, we have subjected HAT ZnO devices to different voltage pulse sequences.…”

Oxygen vacancy effects in HfO2-based resistive switching memory: First principle study

“…Among them, the Transition Metal Oxides (TMOs) are widely considered as the most promising materials, and the conduction filament mechanism in TMO is widely accepted by most people. [14][15][16] Due to the limitations of the experiment in practice (such as the cost and the manufacturing time), simulations and theoretical analysis were used to study the performance parameters. As described by Dearnaley's model, 17 the oxygen vacancy (Vo) defects play a crucial role for resistance switching.…”