Some embodiments relate to an integrated circuit (IC) that includes a semiconductor substrate. A shallow trench isolation region downwardly extends into the frontside of the semiconductor substrate and is filled with dielectric material. A first capacitor plate and a second capacitor plate are disposed in the shallow trench isolation region. The first capacitor plate and the second capacitor plate have first and second sidewall structures, respectively, that are substantially parallel to one another and that are separated from one another by the dielectric material of the shallow trench isolation region.