A semiconductor structure includes a substrate that includes a first region, a second region, and a third region; a first electrode layer disposed over the first region and the second region; a first dielectric layer disposed over the substrate; a second electrode layer disposed on the first dielectric layer over the third region and the second region; a second dielectric layer disposed over the substrate; a third electrode layer disposed on the second dielectric layer over the second region and over a portion of each of the third and first regions; and a first plug disposed over the first region and a second plug disposed over the third region. The first plug is electrically connected with one of the first, second and third electrode layers, and the second plug is electrically connected with the other two electrode layers.