Gidts Michiel, Hsu Wei-Fan, Recaman Payo Maria, Kushwaha Shaswat, Ceyssens Frederik, Reynaerts Dominiek, Locquet Jean-Pierre, Kraft Michael, Wang Chen
Micro- and Nanosystems, Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, 3001, Leuven, Belgium.
Functional Oxides Coating Center, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium.
Microsyst Nanoeng. 2024 Dec 14;10(1):189. doi: 10.1038/s41378-024-00807-0.
Cr-doped VO thin film shows a huge resistivity change with controlled epitaxial strain at room temperature as a result of a gradual Mott metal-insulator phase transition with strain. This novel piezoresistive transduction principle makes Cr-doped VO thin film an appealing piezoresistive material. To investigate the piezoresistivity of Cr-doped VO thin film for implementation in MEMS sensor applications, the resistance change of differently orientated Cr-doped VO thin film piezoresistors with external strain change was measured. With a longitudinal gauge factor of 222 and a transversal gauge factor of 217 at room temperature, isotropic piezoresistivity coefficients were discovered. This results in a significant orientation-independent resistance change with stress for Cr-doped VO thin film piezoresistors, potentially useful for new sensor applications. To demonstrate the integration of this new piezoresistive material in sensor applications, a micromachined pressure sensor with Cr-doped VO thin film piezoresistors was designed, fabricated and characterized. At 20 °C, a sensitivity, offset, temperature coefficient of sensitivity and temperature coefficient of offset of 21.81 mV/V/bar, -25.73 mV/V, -0.076 mV/V/bar/°C and 0.182 mV/V/°C, respectively, were measured. This work paves the way for further research on this promising piezoresistive transduction principle for use in MEMS sensor applications.
由于随着应变发生逐渐的莫特金属-绝缘体相变，Cr掺杂的VO薄膜在室温下随着可控外延应变显示出巨大的电阻率变化。这种新颖的压阻转换原理使Cr掺杂的VO薄膜成为一种有吸引力的压阻材料。为了研究Cr掺杂的VO薄膜在MEMS传感器应用中的压阻特性，测量了不同取向的Cr掺杂VO薄膜压阻器随外部应变变化的电阻变化。在室温下，纵向应变系数为222，横向应变系数为217，发现了各向同性的压阻系数。这导致Cr掺杂VO薄膜压阻器的电阻随应力发生显著的与取向无关的变化，这对于新的传感器应用可能是有用的。为了证明这种新型压阻材料在传感器应用中的集成，设计、制造并表征了一种带有Cr掺杂VO薄膜压阻器的微机械压力传感器。在20℃时，测量得到的灵敏度、失调电压、灵敏度温度系数和失调电压温度系数分别为21.81 mV/V/bar、-25.73 mV/V、-0.076 mV/V/bar/℃和0.182 mV/V/℃。这项工作为进一步研究这种用于MEMS传感器应用的有前景的压阻转换原理铺平了道路。
