Charge injection and decay of nanoscale dielectric films resolved via dynamic scanning probe microscopy
Charge injection and decay of nanoscale dielectric films resolved via dynamic scanning probe microscopy
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DOI：
10.1111/jace.17776
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发表时间：
2021-03-31
影响因子：
3.9
通讯作者：
Huey，Bryan D.
中科院分区：
文献类型：
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作者：
Moran，Thomas J.;Suzuki，Keigo;Huey，Bryan D.
为了满足对多层陶瓷电容器和相关微电子器件中更高性能介电材料的持续需求，新的表征方法是将材料特性映射到纳米尺度的必要条件，在纳米尺度下，使能材料的发展越来越相关。因此，一种基于原子力显微镜的方法被用于表征基于放电动力学映射的绝缘体性能。通过偏置接触介质表面的导电尖端进行表面充电，连续非接触开尔文力表面电位映射（KPFM）揭示了电荷通过指数衰减的耗散。在具有不同微结构但厚度相同的钛酸钡（BTO）薄膜中，放电速率变化可达2倍，较小的晶粒尺寸与较长的耗散时间相关，从而为改善电容器性能提供了最佳微结构的见解。因此，作为时间函数的高分辨率电位映射为直接研究电介质中的电荷注入和放电机制提供了一条途径，电介质越来越多地被设计到纳米级，并且具有全球意义，因为每年制造数万亿这样的器件。
To satisfy continual demands for higher performance dielectrics in multi‐layer ceramic capacitors and related microelectronic devices, novel characterization methods are necessary for mapping materials properties down to the nanoscale, where enabling materials developments are increasingly relevant. Accordingly, an atomic force microscopy‐based approach is implemented for characterizing insulator performance based on the mapping of discharging dynamics. Following surface charging by biasing a conducting tip contacting a dielectric surface, consecutive non‐contact Kelvin force surface potential mapping (KPFM) reveals charge dissipation via exponential decay. In barium titanate (BTO) thin films engineered with distinct microstructures but identical thicknesses, discharging rates vary by up to a factor of 2, with smaller grain size correlating to longer dissipation times, providing insight into optimal microstructures for improved capacitor performance. High‐resolution potential mapping as a function of time thereby provides a route for directly investigating charge injection and discharging mechanisms in dielectrics, which are increasingly engineered down to the nanoscale and have global implications given the trillions of such devices manufactured each year.