Jiang An Quan, Geng Wen Ping, Lv Peng, Hong Jia-Wang, Jiang Jun, Wang Chao, Chai Xiao Jie, Lian Jian Wei, Zhang Yan, Huang Rong, Zhang David Wei, Scott James F, Hwang Cheol Seong
State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai, China.
School of Instrument and Electronics, North University of China, Taiyuan, China.
Nat Mater. 2020 Nov;19(11):1188-1194. doi: 10.1038/s41563-020-0702-z. Epub 2020 Jun 15.
Interfacial 'dead' layers between metals and ferroelectric thin films generally induce detrimental effects in nanocapacitors, yet their peculiar properties can prove advantageous in other electronic devices. Here, we show that dead layers with low Li concentration located at the surface of LiNbO ferroelectric materials can function as unipolar selectors. LiNbO mesa cells were etched from a single-crystal LiNbO substrate, and Pt metal contacts were deposited on their sides. Poling induced non-volatile switching of ferroelectric domains in the cell, and volatile switching in the domains in the interfacial (dead) layers, with the domain walls created within the substrate being electrically conductive. These features were also confirmed using single-crystal LiNbO thin films bonded to SiO/Si wafers. The fabricated nanoscale mesa-structured memory cell with an embedded interfacial-layer selector shows a high on-to-off ratio (>10) and high switching endurance (~10 cycles), showing potential for the fabrication of crossbar arrays of ferroelectric domain wall memories.
金属与铁电薄膜之间的界面“死”层通常会在纳米电容器中产生有害影响，但其独特性质在其他电子器件中可能具有优势。在此，我们表明位于铌酸锂铁电材料表面的低锂浓度死层可作为单极选择器。从单晶铌酸锂衬底蚀刻出铌酸锂台面单元，并在其侧面沉积铂金属接触。极化诱导单元中铁电畴的非易失性切换以及界面（死）层中畴的易失性切换，且衬底内形成的畴壁具有导电性。使用键合到SiO/Si晶圆上的单晶铌酸锂薄膜也证实了这些特性。所制备的具有嵌入式界面层选择器的纳米级台面结构存储单元显示出高开关比（>10）和高开关耐久性（~10次循环），展现出制造铁电畴壁存储器交叉阵列的潜力。
