Park Yunkyu, Yoon Daseob, Fukutani Keisuke, Stania Roland, Son Junwoo
Department of Materials Science and Engineering (MSE) , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea.
Center for Artificial Low Dimensional Electronic Systems , Institute for Basic Science (IBS) , Pohang 37673 , Republic of Korea.
ACS Appl Mater Interfaces. 2019 Jul 10;11(27):24221-24229. doi: 10.1021/acsami.9b04015. Epub 2019 Jun 27.
Super-steep two-terminal electronic devices using NbO, which abruptly switch from insulator to metal at a threshold voltage (), offer diverse strategies for energy-efficient and high-density device architecture to overcome fundamental limitation in current electronics. However, the tight control of stoichiometry and high-temperature processing limit practical implementation of NbO as a component of device integration. Here, we demonstrate a facile room-temperature process that uses solid-solid phase transformation induced by pulsed laser to fabricate NbO-based threshold switches. Interestingly, pulsed laser annealing under a reducing environment facilitates a two-step nucleation pathway (a-NbO → o-NbO → t-NbO) of the threshold-enabled NbO phase mediated by oxygen vacancies in o-NbO. The laser-annealed devices with embedded NbO crystallites exhibit excellent threshold device performance with low off-current and high on/off current ratio. Our strategy that exploits the interactions of pulsed lasers with multivalent metal oxides can guide the development of a rational route to achieve NbO-based threshold switches that are compatible with current semiconductor fabrication technology.
使用NbO的超陡双端电子器件在阈值电压（）下从绝缘体突然转变为金属，为节能和高密度器件架构提供了多种策略，以克服当前电子学中的基本限制。然而，化学计量比的严格控制和高温处理限制了NbO作为器件集成组件的实际应用。在此，我们展示了一种简便的室温工艺，该工艺利用脉冲激光诱导的固-固相变来制造基于NbO的阈值开关。有趣的是，在还原环境下的脉冲激光退火促进了由o-NbO中的氧空位介导的阈值启用NbO相的两步成核途径（a-NbO → o-NbO → t-NbO）。具有嵌入式NbO微晶的激光退火器件表现出优异的阈值器件性能，具有低关断电流和高开/关电流比。我们利用脉冲激光与多价金属氧化物相互作用的策略可以指导开发一条合理的路线，以实现与当前半导体制造技术兼容的基于NbO的阈值开关。
