Increased electromechanical coupling in w-ScxAl1-xN

AlN is challenged as the material choice in important thin film electroacoustic devices for modern wireless communication applications. We present the promise of superior electromechanical coupling (k(t)(2)), in w-ScxAl1-xN by studying its dielectric properties. w-ScxAl1-xN (0 <= x <= 0.3) thin films grown by dual reactive magnetron sputtering exhibited low dielectric losses along with minor increased dielectric constant (epsilon). Ellipsometry measurements of the high frequency epsilon showed good agreement with density function perturbation calculations. Our data show that k(t)(2) will improve from 7% to 10% by alloying AlN with up to 20 mol % ScN. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3489939]