An Increasing High Resistance State Phenomenon in Al/VO_x/Cu Resistive Switching Device

Abstract

In this paper, we reported increasing high resistance state (HRS) phenomenon of Al/VO x /Cu resistive random access memory (RRAM). The current of HRS became lower in current-voltage (I-V) curves and resistance of HRS gradually increased from a lower pristine sate to a higher HRS during cycling operation. Schottky emission theory was employed to investigate the HRS conduction. We found that the slope of HRS I-V curves on ln(J) and sqrt(V) plot decreased after cycling operation. According to Schottky emission theory, we concluded that generation of AlO x layer between Al electrode and VO x film was the cause of increasing HRS resistance. We finally verify the conclusion by data retention under constant voltage stress.

Reduction of optical bleaching in phosphorus doped Ge layer on Si

“…Since the reduction in absorption coefficient for both samples is > 0, OB dominates the pump-induced free carrier absorption. Similar observations have been reported in [7,8]. However, for a fixed excited carrier concentration of 1×10 19 cm -3 , optical bleaching in the doped Ge layer is suppressed as compared to that of undoped Ge, as clearly shown in Fig.…”

Conduction Mechanism of Valence Change Resistive Switching Memory: A Survey

“…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.…”

“…Sun Kuo et al employed Schottky emission to explain the increasing HRS resistance during cycling operation on the Al/VOx/Cu [38]. Noted that Al electrode has lower work function (4.28 eV) thus can form a Schottky barrier with p-type VOx that has higher work function of 4.7 eV.…”

“…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...…”

Electron Emission Devices for Energy‐Efficient Systems

“…c) Typical Schottky plot. (b,c) Reproduced with permission . Copyright 2014, Electrochemical Society.…”