A two terminal semiconducting device like a memristor is indispensable to emulate the function of synapse in the working memory. The analog switching characteristics of memristor play a vital role in the emulation of biological synapses. The application of consecutive voltage sweeps or pulses (action potentials) changes the conductivity of the memristor which is considered as the fundamental cause of the synaptic plasticity. In this study, a neuromorphic device using an in-situ growth of sub-tantalum oxide switching layer is fabricated, which exhibits the digital SET and analog RESET switching with an electroforming process without any compliance current (compliance free). The process of electroforming and SET is observed at the positive sweeps of +2.4 V and +0.86 V, respectively, while multilevel RESET is observed with the consecutive negative sweeps in the range of 0 V to -1.2 V. The movement of oxygen vacancies and gradual change in the anatomy of the filament is attributed to digital SET and analog RESET switching characteristics. For the Ti/Ta₂O_3-x/Pt neuromorphic device, the Ti top and Pt bottom electrodes are considered as counterparts of the pre-synaptic input terminal and a post-synaptic output terminal, respectively.

中文翻译：

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基于亚氧化钽的神经形态设备的无遵从性，数字SET和模拟RESET突触特性。

像忆阻器这样的两端子半导体器件对于模拟工作存储器中突触的功能是必不可少的。忆阻器的模拟开关特性在模拟生物突触中起着至关重要的作用。连续施加电压扫描或脉冲（动作电位）会改变忆阻器的电导率，这被认为是突触可塑性的根本原因。在这项研究中，制造了使用原位生长亚钽氧化物开关层的神经形态器件，该器件通过电铸工艺显示出数字SET和模拟RESET开关，而没有任何顺从电流（无遵从性）。分别在+2.4 V和+0.86 V的正扫描上观察到电铸和SET的过程，而在连续的负扫描范围为0 V至-1.2 V的情况下观察到多级RESET。氧空位的移动和灯丝解剖结构的逐渐变化归因于数字SET和模拟RESET开关特性。对于钛/钽_在2 O _3-x / Pt神经形态装置中，Ti顶部电极和Pt底部电极分别被视为突触前输入端子和突触后输出端子的对应物。