Zhang Wen Jie, Wang Chao, Jiang Jun, Jiang An Quang
State Key Laboratory of ASIC & System School of Microelectronics, Fudan University, Shanghai 200433, China.
ACS Appl Mater Interfaces. 2022 Jul 20;14(28):32227-32235. doi: 10.1021/acsami.2c05923. Epub 2022 Jul 8.
The microampere-level domain wall currents in LiNbO single crystals have promising applications in nonvolatile ferroelectric domain wall random access memory and logic with high-density integration, ultrafast operation speeds, and almost unlimited switching cycles. For the memory commercialization, the improvements of the reliability and operation speed of the devices are challenging due to the high-field charge injection. The injected charge could compensate the domain-wall boundary charge that screens the domain switching field and reduces the domain wall current. In this work, two kinds of memory nanocells were fabricated on the surfaces of X-cut LiNbO single crystals to study the geometry-dependent charge injection. The striped memory cell due to the appearance of the size-driven reconstruction has a smaller coercive field than that of a clamped memory cell without relaxation of the lattice matching stress, which reduces low-frequency charge injection and increases the domain switching speed. At an operating voltage of 5 V, we observed a retention time of more than 1 week and an on/off current ratio of 2 × 10 for a striped-like cell, paving the route to integrate energy-efficient high-density domain wall memory in high reliability.
铌酸锂（LiNbO）单晶中的微安级畴壁电流在非易失性铁电畴壁随机存取存储器以及具有高密度集成、超快运行速度和几乎无限开关周期的逻辑器件中有着广阔的应用前景。对于存储器商业化而言，由于高场电荷注入，提高器件的可靠性和运行速度具有挑战性。注入的电荷会补偿屏蔽畴开关场并降低畴壁电流的畴壁边界电荷。在这项工作中，在X切铌酸锂单晶表面制备了两种存储纳米单元，以研究与几何形状相关的电荷注入。由于尺寸驱动重构的出现，条纹状存储单元的矫顽场比没有晶格匹配应力松弛的夹紧存储单元小，这减少了低频电荷注入并提高了畴开关速度。在5V的工作电压下，我们观察到条纹状单元的保持时间超过1周，开/关电流比为2×10，为在高可靠性下集成节能型高密度畴壁存储器铺平了道路。
