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In the last decade, a surge in research on hafnium oxide (HfOx)-based ferroelectricity has become a significant part of the semiconductor research trend. In this work, we present a new factor, that is, process damage to the HfOx-based ferroelectric implementation. By reversely exploiting harmful damage in the metal-oxide-semiconductor process, the ferroelectricity in HfOx is improved by eliciting early amorphization suitable for orthorhombic phase formation. In addition, through various pulsed polarization measurements, it is found that the damaged HfOx film has a fast polarization switching speed, with an initial pinning site that is suitable for domain wall growth motion; advantageous for high-performance memory applications. [ABSTRACT FROM AUTHOR]

We propose self-rectifying resistive random access memory (RRAM) synapse to prevent reverse leakage current problem which occurs when RRAM is integrated with integrate and fire (IF) circuit in spiking neural network (SNN). Ni/W/SiNx/n-Si RRAM was fabricated by varying the bottom electrode (BE) doping concentration and their rectifying characteristics were analyzed. Low BE doping concentration device showed self-rectifying characteristics without any additional selector or diode device. Furthermore, hardware-based system-level simulation was conducted to evaluate the effect of self-rectifying RRAM synapse on MNIST classification accuracy. About 93.34% accuracy was obtained using the proposed RRAM. [ABSTRACT FROM AUTHOR]

In this article, we report a method for recovering a resistive-switching random access memory (RRAM) from the reset breakdown and enhancing the endurance characteristics. A SiNx-based RRAM device has been fabricated and its switching characteristics are analyzed with a particular interest in reset breakdown. It has been found that the SiNx RRAM in permanent reset breakdown can be revived to high-resistance state (HRS) by thermal recovery, a low-temperature annealing method. The memory window could be widened even with enhanced reset stability and conductance distribution. Temperature-dependent conductance change has been measured in order to figure out the substantial component of conductive filament and the mechanism of thermal recovery. The experimental evidences show that the reset breakdown process is the result of unwanted Si dangling bond (Si-DB) formation. By thermal recovery, Ni filament could be ruptured without applying a high electric field which induces negative set. [ABSTRACT FROM AUTHOR]