Scalability of voltage-controlled filamentary and nanometallic resistance memory devices

Abstract

Much effort has been devoted to device and materials engineering to realize nanoscale resistance random access memory (RRAM) for practical applications, but a rational physical basis to be relied on to design scalable devices spanning many length scales is still lacking. In particular, there is no clear criterion for switching control in those RRAM devices in which resistance changes are limited to localized nanoscale filaments that experience concentrated heat, electric current and field. Here, we demonstrate voltage-controlled resistance switching, always at a constant characteristic critical voltage, for macro and nanodevices in both filamentary RRAM and nanometallic RRAM, and the latter switches uniformly and does not require a forming process. As a result, area-scalability can be achieved under a device-area-proportional current compliance for the low resistance state of the filamentary RRAM, and for both the low and high resistance states of the nanometallic RRAM. This finding will help design area-scalable RRAM at the nanoscale. It also establishes an analogy between RRAM and synapses, in which signal transmission is also voltage-controlled.

Comparison of diverse resistive switching characteristics and demonstration of transitions among them in Al-incorporated HfO2-based resistive switching memory for neuromorphic applications

“…40 Table 1 compares the ON/OFF ratio, the endurance cycle, the linearity, the weight update error rate of potentiation and depression, and the read margin for the three types of switching. The Pt/HfAlO x /TiN device shows good stability as well as multilevel and tunable switching based on different measurement conditions such as CC, 42 bias polarity, and voltage sweep range, 43 which are explained in the ow chart presented in the inset in Fig. 9.…”

Purely electronic nanometallic resistance switching random-access memory

“…Regardless of the type, simple methods can help clarify ReRAM characteristics-pressure tests to detect nonionic switching and fracture tests to confirm filamentary switching. Finally, methods are now available to remove the load effect to reveal the true voltage, 14,16 area, 14 temperature, and magnetic-field scaling 8,17 in these two-terminal devices.…”

Electroforming-Free Bipolar Resistive Switching Memory Based on Magnesium Fluoride

“…After the SET process, charge carriers flowed through the conduction filament (CF) instead of the whole device area in the LRS. After the RESET process, current contribution is dominated by thermally activated localized states at the partially ruptured filaments and not by the bulk layer [23][24][25][26][27].…”