Accurate analysis of conduction and resistive-switching mechanisms in double-layered resistive-switching memory devices

Abstract

Resistive-switching and current conduction mechanisms have been studied in TiN/Ti/TiOx/HfOx/TiN resistive-switching random access memories (RRAMs). From I-V characteristics and temperature measurement, thermionic emission is found to be the most appropriate mechanism representing the dominant current conduction in all the bias regions and resistance states. Low-frequency noise power spectrum is measured to analyze accurately the conduction mechanism, which corroborates the thermionic-emission. Also, using the migration of oxygen ions depending on the polarity of the applied field, we propose the resistive-switching model of a double-layered RRAM to explain the unique resistive-switching characteristics.

Conduction Mechanism of Valence Change Resistive Switching Memory: A Survey

“…TiN/Ti/TiOx/TiN structure and the double-layered TiN/Ti/TiOx/HfOx/TiN structure [35]. It is clearly seen that the single layer structure demonstrates stronger symmetrical property in I-V characteristic compared to double layered structure.…”

“…Hence, the existence of Schottky emission can be ascertained by fitting to two functions, which are: (i) ln(J/T 2 ) ∝ 1/T under fixed electric field; and (ii) ln(J) ∝ E 1/2 under fixed temperature. There are numerous published resistive switching devices that suggested Schottky emission as the dominant conduction mechanism, such as [33][34][35][36][37][38][39][40][41][42], etc. The combination of electrodes and materials of these works is listed in Table 3.…”

“…While CF evolution is typically associated with thermal, electrical or ion migration [19,20], there is no consensus on the dominant conduction mechanism in resistive switching memory devices [21][22][23]. Among the commonly observed conduction mechanisms are: (i) Poole-Frenkel emission [24][25][26][27][28][29][30][31][32]; (ii) Schottky emission [33][34][35][36][37][38][39][40][41][42]; (iii) SCLC [43][44][45][46][47][48][49][50][51][52][53] (iv) trap-assisted tunneling [54][55][56][57][58][59]; and (v) hopping conduction [60][61][62][63][64][65]. To enhance the device performance and data retention property, it is crucial to identifying t...…”

Effect of Bottom Electrode on Resistive Switching Voltages in Ag-Based Electrochemical Metallization Memory Device

“…It is due to the fact that the conducting filaments are not totally ruptured by partially disconnected in the vicinity of TE. Thus, although forming voltage is largely determined by the thickness of SL since the initial connection by conducting filament between BE and TE takes place through the SL, the set and reset voltages are conditions fully considering the material parameters [9,22]. Fig.…”

Investigation of thermal stability and reliability of HfO2 based resistive random access memory devices with cross-bar structure

“…Al 2 O 3 has a lower Gibbs free energy (À1676 kJ/mol) than both TiO 2 (À994 kJ/ mol) and HfO 2 (À1145 kJ/mol). 31 Materials with a lower Gibbs free energy are more stable than higher Gibbs free energy materials.…”