An apparatus includes first and second electrodes separated by an insulative material (such as a piezoelectric material). The apparatus also includes a protective layer over the first and second electrodes. The protective layer has a first opening that exposes a portion of the first electrode and a second opening that exposes a portion of the second electrode. The apparatus further includes a first electrical contact at least partially within the first opening and electrically coupled to the first electrode. In addition, the apparatus includes a second electrical contact at least partially within the second opening and electrically coupled to the second electrode. Each of the first and second electrical contacts includes a stack of metal layers. The stack of metal layers includes a titanium nitride layer, a titanium layer over the titanium nitride layer, and an aluminum copper layer over the titanium nitride layer and the titanium layer.