Signal and Thermal Integrity Analysis of 3-D Stacked Resistive Random Access Memories

Abstract

In this article, a 3-D electrothermal numerical model is used to perform the signal and thermal integrity analysis of 3-D stacked Resistive-switching random access memory (RRAM) arrays. Two main issues are found: voltage drop along the interconnects and thermal crosstalk between the memory cells. Possible solutions to these issues are here thoroughly investigated, based either on new biasing schemes or new materials. Especially, conventional nickel bars are replaced by interconnects made by copper (Cu) and carbon nanotubes (CNTs), whose electrical and thermal parameters are here described using physically based models. The analysis is performed on a 5 × 5 × 5 array, under a real case of a RESET switching, which is the worst case scenario from the electrothermal point of view. Simulation results show that the use of CNTs reduces the voltage drop in both word and bitline (BL) interconnects, thermal crosstalk, and the maximum working temperature; hence, it mitigates many of the crucial issues in the roadmap for the large-scale monolithic 3-D RRAM integration.

Emulating Artificial Synaptic Plasticity Characteristics from SiO2-Based Conductive Bridge Memories with Pt Nanoparticles

“…Moreover, as can be ascertained from the TEM plan view image of the Pt NCs (inset of Figure 1 a), the NCs do not exhibit any preferred morphology and several irregular shapes can be detected, which could likewise impact the electric field distribution. Moreover, the thermal conductivity values of the BE has a pronounced impact on the local Joule heat distribution [ 19 ], as is disclosed later in the analytical modeling section. The result of the abovementioned factors is the enhanced thermal accelerated migration of silver ions that could interpret the steeper transition slopes.…”

A physics-based compact model of thermal resistance in RRAMs

“…Commercial implementation of RRAM requires a high density of devices, thus making it essential to study the effect of thermal crosstalk. To this end, several works based on numerical simulation [24][25][26][27] and experimental studies [12-14, 28, 29] have been reported in the literature. In [24,26], using numerical simulations, the authors demonstrated the dominant role of transient thermal effects on the reset mechanism, the impact of thermal crosstalk on RRAM retention characteristics, and the scaling potential of 3-D RRAM arrays.…”

“…On similar lines, authors in [25] have proposed two types of structures, coined as the 'thermal house' (TH), that facilitate thermal management, and studied electro-thermal effects in 3-D RRAM crossbar arrays through detailed numerical simulations. In [27], a 3-D electro-thermal numerical model is used to perform the signal and thermal integrity analysis of 3-D stacked Resistive-switching random access memory (RRAM) arrays. The experimental work in [28] has measured the temperature profile of TaO x RRAM during the operation using an ultra-fast imaging system.…”