Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA.
Science. 2023 Jun 9;380(6649):1034-1038. doi: 10.1126/science.adh7670. Epub 2023 Jun 8.
Ferroelectric wurtzites have the potential to revolutionize modern microelectronics because they are easily integrated with multiple mainstream semiconductor platforms. However, the electric fields required to reverse their polarization direction and unlock electronic and optical functions need substantial reduction for operational compatibility with complementary metal-oxide semiconductor (CMOS) electronics. To understand this process, we observed and quantified real-time polarization switching of a representative ferroelectric wurtzite (AlBN) at the atomic scale with scanning transmission electron microscopy. The analysis revealed a polarization reversal model in which puckered aluminum/boron nitride rings in the wurtzite basal planes gradually flatten and adopt a transient nonpolar geometry. Independent first-principles simulations reveal the details and energetics of the reversal process through an antipolar phase. This model and local mechanistic understanding are a critical initial step for property engineering efforts in this emerging material class.
铁电纤锌矿结构有潜力彻底改变现代微电子学，因为它们很容易与多种主流半导体平台集成。然而，为了与互补金属氧化物半导体（CMOS）电子设备兼容，需要大幅度降低反转其极化方向和解锁电子和光学功能所需的电场。为了理解这一过程，我们使用扫描透射电子显微镜在原子尺度上观察和量化了代表性铁电纤锌矿（AlBN）的实时极化反转。分析揭示了一种反转模型，其中纤锌矿基面中的褶皱的铝/氮化硼环逐渐变平并采用瞬态非极性几何形状。独立的第一性原理模拟通过反铁电相揭示了反转过程的细节和能量学。该模型和局部机械理解是对这一新兴材料体系进行性能工程研究的关键初始步骤。
