Evolution of millimetric-range electrostatic forces between an AFM cantilever and a charged dielectric via suspended force curves
Evolution of millimetric-range electrostatic forces between an AFM cantilever and a charged dielectric via suspended force curves
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AFM 悬臂和带电电介质之间毫米级静电力通过悬浮力曲线的演变
DOI：
10.1080/00218464.2021.1969922
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Yuguo Chen
中科院分区：
文献类型：
--
作者：
Tianmao Lai;Mingli Guo;Yuguo Chen
摘要通过在原子力显微镜（AFM）上记录固定距离处的“悬浮”力曲线，研究了硅悬臂梁与带负电荷的电介质样品之间毫米级静电力的演化。结果表明，长程力随时间先急剧增加，然后逐渐增加，直至达到全局最大值，最后略有下降，并呈指数关系。急剧增加是由于高速载流子漂移造成的。此外，由于积累的电荷导致的排斥电场导致温和的增加趋势。此外，指数下降归因于样品表面上的电荷衰减。随着样品缺席一段时间（缺席时间）和再次出现，力再次急剧增加，具有较低的值。缺席时间越长，下降率越大。这是由于浓度差引起的载流子扩散。该方法可用于测量毫米级的静电力，并研究其随时间的演化，以及一些因素对电荷耗散的影响。此外，结果可能表明，AFM硅悬臂梁内的电荷载流子在静电力的贡献中发挥作用。
ABSTRACT The evolution of millimetric-range electrostatic force between a silicon cantilever and a negatively charged dielectric sample was studied by recording “suspended” force curves at a fixed distance on an atomic force microscope (AFM). Results show that the long-range force increases sharply at first with time, then increases moderately until reaching a global maximum, and at last decreases slightly and exponentially. The sharp increase was attributed to carrier drift at a high velocity. Moreover, a repelling electric field due to accumulated charges leads to the moderate increasing trend. In addition, the exponential decrease was attributed to charge decay on the sample surface. With the absence of the sample for a while (absent time) and presence again, the force increases sharply again with a lower value. The longer the absent time, the larger the decreasing rate. This was attributed to carrier diffusion due to the concentration difference. The proposed method can be used to measure millimetric-range electrostatic forces at a fixed distance, and investigate its evolution with time, and study the effect of some factors on the charge dissipation. Furthermore, the outcomes may suggest that charge carriers inside an AFM silicon cantilever play a part in the electrostatic force contribution.