Scandumu aluminium nitride vibration energy harvester with a stres compensation

This paper reports a ScAlN vibration energy harvester (VEH). A ScAlN thin film has a large piezoelectric effect and can be deposited by a standard sputtering method. These advantages are much attractive to piezoelectric Si MEMS cantilever VEHs. However, a ScAlN thin film has a large compressive stress of ∼1 GPa, resulting in a decrease in an efficiency of energy harvesting. In this paper, we introduced an AlN stress compensation layer inserted in between a bottom electrode and a ScAlN film. The fabricated cantilever generated a DC power that is higher by 66% than that without the compensation.