Embodiments of the present disclosure include devices and sensor packages and methods of forming the same. An embodiment is a device including a first semiconductor chip. The first semiconductor chip includes a first substrate, a first conductive pad over the first substrate. The device further includes a second semiconductor chip having a second surface bonded to a first surface of the first semiconductor chip. The second semiconductor chip includes a second substrate and a second conductive pad over the second substrate. The second conductive pad and the first conductive pad form a first capacitor.