Piezoelectric characteristic of nanocrystalline AlN films obtained by pulsed laser deposition at room temperature

Aluminum nitride (AlN) thin films were deposited at room temperature by pulsed laser deposition, and their nanostructure and piezoelectric properties were investigated as a function of fluence. For all fluences, the films were found to consist of an amorphous AlN matrix containing crystalline AlN nanoparticles with size of 6-7 nm. These nanoparticles spark off the good piezoelectric response, with d(33) piezoelectric coefficients between 2.3 and 3.8 pm V(-1), similar to those obtained for (002)-oriented AlN films deposited at higher temperatures. These results indicate that nanocrystalline AlN films deposited at room temperature are good candidates for integration in acoustic wave applications. (C) 2010 American Institute of Physics. [doi:10.1063/1.3527924]