Investigation of resistive switching behaviours in WO₃-based RRAM devices

Abstract

Lian Wen-Tai(连文泰) b) , Liu Su(刘 肃) a) † , and Liu Ming(刘 明) b)

An overview of resistive random access memory devices

“…The dependence of resistive switching on both top and bottom electrode materials has recently been reported [4,15,37]. For some RRAM devices, different electrode materials seem to cause different resistive-switching behaviors, which might depend on the barrier height at the electrode/resistive switching-layer interface.…”

“…To satisfactorily solve the problem of low device yield for nonstoichiometric oxides, Wu et al [14] utilized stoichiometric ZrO 2 instead of nonstoichiometric ZrO 2 for nonvolatile RRAM devices. In addition to this, other methods have been proposed to improve device yield, such as using a suitable electrode material [4], utilizing doped metal oxide [17], and intentionally introducing metal nanocrystals in oxide [28].…”

“…Consequently, the conductive filament can be formed easily with Al as the bottom electrode and the forming process is avoided. On the other hand, we investigated the effect of different top electrodes on the resistive-switching characteristics of WO 3 -based RRAM devices [4]. Compared with the Al/WO 3 /Pt and Cr/WO 3 /Pt devices, the Cu/WO 3 /Pt device has much better resistive-switching characteristics, such as good reproducibility, low power consumption, multilevel storage, and good data retention [4,5].…”

“…On the other hand, we investigated the effect of different top electrodes on the resistive-switching characteristics of WO 3 -based RRAM devices [4]. Compared with the Al/WO 3 /Pt and Cr/WO 3 /Pt devices, the Cu/WO 3 /Pt device has much better resistive-switching characteristics, such as good reproducibility, low power consumption, multilevel storage, and good data retention [4,5]. The excellent resistive-switching characteristics of the Cu/WO 3 /Pt device can be attributed to the electrochemical reactions and migration of the electrochemically active metal Cu in WO 3 film [4].…”

“…It has been reported that doped oxides show better device yield [17]. In addition, compared with non-doped oxides, doped oxides have excellent memory characteristics such as satisfactory switching endurance cycles, potential multilevel storage, long data retention times, and fast switching [4,17,28]. To further confirm the role of metal doping in resistive switching, Guan et al [28] intentionally fabricated a device with Au nanocrystals embedded in ZrO 2 film.…”