Long Xiao, Tan Huan, Sánchez Florencio, Fina Ignasi, Fontcuberta Josep
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra08193, Catalonia, Spain.
ACS Appl Electron Mater. 2023 Jan 30;5(2):740-747. doi: 10.1021/acsaelm.2c01186. eCollection 2023 Feb 28.
The recent discovery of ferroelectricity in doped HfO has opened perspectives on the development of memristors based on ferroelectric switching, including ferroelectric tunnel junctions. In these devices, conductive channels are formed in a similar manner to junctions based on nonferroelectric oxides. The formation of the conductive channels does not preclude the presence of ferroelectric switching, but little is known about the device ferroelectric properties after conduction path formation or their impact on the electric modulation of the resistance state. Here, we show that ferroelectricity and related sizable electroresistance are observed in pristine 4.6 nm epitaxial HfZrO (HZO) tunnel junctions grown on Si. After a soft breakdown induced by the application of suitable voltage, the resistance decreases by about five orders of magnitude, but signatures of ferroelectricity and electroresistance are still observed. Impedance spectroscopy allows us to conclude that the effective ferroelectric device area after the breakdown is reduced, most likely by the formation of conducting paths at the edge.
最近在掺杂的HfO中发现铁电性，为基于铁电开关的忆阻器（包括铁电隧道结）的发展开辟了前景。在这些器件中，导电通道的形成方式与基于非铁电氧化物的结类似。导电通道的形成并不排除铁电开关的存在，但对于传导路径形成后器件的铁电特性或其对电阻状态电调制的影响知之甚少。在此，我们表明在生长于Si上的原始4.6nm外延HfZrO（HZO）隧道结中观察到了铁电性和相关的可观电致电阻。在施加合适电压引起软击穿后，电阻降低约五个数量级，但仍观察到铁电性和电致电阻的特征。阻抗谱使我们能够得出结论，击穿后有效铁电器件面积减小，很可能是由于边缘处形成了导电路径。
