Electrical device comprising a 3d capacitor and a region surrounded by a through opening

An electrical device comprising:

• a semiconductor substrate having a top face and a bottom face;
• a 3D capacitor including a capacitor dielectric region of a dielectric material, a capacitor electrode region of a conductive material, the capacitor dielectric region and the capacitor electrode region being arranged at least partially inside a cavity extending in the substrate from the top face;
• and
• a surrounding through opening formed in the substrate and which surrounds a surrounded substrate region, the 3D capacitor being outside of the surrounded substrate region, the surrounding through opening extending from the top face to the bottom face of the substrate,
• wherein inside the surrounding through opening a surrounding dielectric region of the dielectric material and a surrounding conductive region of the conductive material are arranged, the surrounding dielectric region extending in the surrounding through opening from the top face to the bottom face of the substrate and all around the surrounded substrate region.