Large-scale (512kbit) integration of multilayer-ready access-devices based on mixed-ionic-electronic-conduction (MIEC) at 100% yield

Abstract

BEOL-friendly Access Devices (AD) based on Cu-containing MIEC materials [1][2][3][4] are integrated in large (512×1024) arrays at 100% yield, and are successfully co-integrated together with Phase Change Memory (PCM). Numerous desirable attributes are demonstrated: the large currents (>200µA) needed for PCM, the bipolar operation required for high-performance RRAM, the single-target sputter deposition essential for high-volume manufacturing, and the ultra-low leakage (< 10 pA) and high voltage margin (1.5V) needed to enable large crosspoint arrays.

Threshold switching behavior of Ag-Si based selector device and hydrogen doping effect on its characteristics

“…[3][4][5] An alternative method is to connect a nonlinear circuit element such as a selector device to each RRAM cell as one selector and one resistor 1S-1R configuration. Several selector devices such as tunneling didoes, 6 bidirectional varistors, 7 mixed-ionic-electronic-conduction (MIEC), 8 Ovonic threshold switching (OTS) 9 and metal-insulator transition (MIT) have been proposed. 10 However, these selector devices cannot sufficiently suppress the leakage current, which is required for achieving high density RRAM integration.…”

A plasma-treated chalcogenide switch device for stackable scalable 3D nanoscale memory

“…However, the three-terminal Si transistors are not suitable for 3D crossbar stacked structure due to their high processing temperature and difficulty in both scaling and stacking 8,9 . Recently, various bidirectional select devices, for instance the varistor-type switch 16 and mixed-ionic-electronic-conduction device 17 have been proposed for bipolar resistive memory applications. The threshold switching (TS) devices are able to overcome the previous limitations by imitating bidirectional diode-like behaviour while being composed of a single compound and providing sufficient current density.…”

Memory Select Devices

“…A so-called mixed ionic electronic conduction (MIEC) device is developed as select devices for PCM [64][65][66][67]. The device is made from Cu-containing MIEC materials sandwiched between an inert top electrode (TE; e.g., TiN, W) and a bottom electrode (BE).…”

“…Endurance of MIEC increases exponentially with decreasing current and is independent of device sizes. The MIEC select devices were also integrated with PCM in a 512 kb testing array using 180 nm CMOS process and achieved 100% yield [66]. Electrode optimization plays critical roles in the yield improvement.…”