The piezoresistive property of an aluminum (Al)-doped zinc oxide (AZO) thin film (thickness = 20 nm) is evaluated using a microfabricated silicon cantilever structure. The AZO thin film is deposited via atomic-layer deposition with 5% Al doping. An AZO piezoresistor is patterned at the root of the cantilever. This cantilever device is fabricated using conventional microfabrication techniques such as lithography, lift-off, ion milling, and dry/wet etching. The cantilever is deflected by pressing the tip of the cantilever by a needle mounted on a micromanipulator. The strain of the AZO pattern caused by the deflection is numerically calculated using a finite element method based on the dimensions and materials of the fabricated device. The output current of the AZO changes almost linearly with increase in the input voltage. The gauge factor of the AZO thin-film piezoresistor is found to be 8.5.
|IEEJ Transactions on Electrical and Electronic Engineering
|Published - 2017 Dec
- atomic-layer deposition
- microelectromechanical systems/nanoelectromechanical systems
- zinc oxide