Ferroelectric (FE) capacitor is a critical electric component in microelectronic devices. Among many of its intriguing properties, the recent finding of voltage drop (V-drop) across the FE capacitor while the positive charges flow in is especially eye-catching. This finding was claimed to be direct evidence that the FE capacitor is in negative capacitance (NC) state, which must be useful for (infinitely) high capacitance and ultralow voltage operation of field-effect transistors. Nonetheless, the NC state corresponds to the maximum energy state of the FE material, so it has been widely accepted in the community that the material alleviates that state by forming ferroelectric domains. This work reports a similar V-drop effect from the 150 nm thick epitaxial BaTiO₃ ferroelectric thin film, but the interpretation was completely disparate; the V-drop can be precisely simulated by the reverse domain nucleation and propagation of which charge effect cannot be fully compensated for by the supplied charge from the external charge source. The disappearance of the V-drop effect was also observed by repeated FE switching only up to 10 cycles, which can hardly be explained by the involvement of the NC effect. The retained reverse domain nuclei even after the subsequent poling can explain such behavior.

中文翻译：

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迟延磁畴成核法在铁电单层电容器中的电压降

铁电（FE）电容器是微电子设备中的关键电子组件。在其许多吸引人的特性中，最近发现的是，当正电荷流入时，FE电容器两端的电压降（V-drop）尤其引人注目。声称这一发现是FE电容器处于负电容（NC）状态的直接证据，这对于（无限）场效应晶体管的高电容和超低电压操作必不可少。尽管如此，NC状态对应于FE材料的最大能量状态，因此在社区中已广泛接受该材料通过形成铁电畴来缓解该状态。这项工作报道了150 nm厚外延BaTiO ₃的类似V降效应铁电薄膜，但解释是完全不同的；通过反向域成核和传播，可以精确地模拟V降，其电荷效应不能完全由外部电荷源提供的电荷来补偿。V-drop效应的消失还通过重复的FE切换（最多10个循环）而观察到，这很难通过NC效应的参与来解释。即使在随后的极化之后，保留的反向域核也可以解释这种行为。