The in‐plane piezoelectric response of 20 nm thick Si‐doped HfO₂ is examined by exploiting thermal expansion of the substrate upon rapid temperature cycling. The sample is heated locally by a deposited metal film, and the subsequently registered pyroelectric current is found to be frequency dependent in the observed range of 5 Hz to 35 kHz. While the intrinsic response remains constant, the secondary contribution can be switched off in the high‐frequency limit due to substrate clamping. As this secondary response is generated by thermal expansion and the piezoelectric effect, this allows for extraction of the corresponding in‐plane response. By comparing pyroelectric measurements in low‐ and high‐frequency limits, a piezoelectric coefficient d₃₁ of −11.5 pm V ⁻¹ is obtained, which is more than five times larger than that of AlN. The magnitude of piezoelectric response increases upon electric field cycling, which is associated with a transition from antiferroelectric‐like behavior to a purely ferroelectric polarization hysteresis. The hafnium oxide material system is proposed as a promising candidate for future CMOS compatible piezoelectric micro‐ and nano‐electromechanical systems (MEMS and NEMS).

中文翻译：

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快速温度循环确定多晶硅掺杂氧化Ha薄膜的压电响应

通过在快速温度循环后利用基板的热膨胀来检查20 nm厚的掺Si HfO ₂的面内压电响应。样品通过沉积的金属膜局部加热，随后发现的热释电电流在观察到的5 Hz至35 kHz范围内与频率有关。虽然固有响应保持恒定，但由于基板夹紧，可以在高频极限中关闭次要作用。由于该次级响应是由热膨胀和压电效应产生的，因此可以提取相应的面内响应。通过比较低频和高频限制下的热电测量，压电系数d ₃₁为-11.5 pm V所获得的^-1是AlN的五倍以上。压电响应的强度随电场循环而增加，这与从类似反铁电行为到纯铁电极化磁滞的转变有关。氧化ha材料系统被提议为未来CMOS兼容的压电微和纳米机电系统（MEMS和NEMS）的有希望的候选者。