A semiconductor device structure is disclosed including a semiconductor-on-insulator (SOI) substrate, the SOI substrate comprising a semiconductor layer, a substrate material and a buried insulating material layer positioned between the semiconductor layer and the substrate material, a trench isolation structure positioned in at least a portion of the SOI substrate, the trench isolation structure defining a first region in the SOI substrate, and a capacitor device formed in the first region, the capacitor device comprising a first electrode formed by a conductive layer portion formed in the first region on the buried insulating material layer, the conductive layer portion at least partially replacing the semiconductor layer in the first region, a second electrode formed over the first electrode, and an insulating material formed between the first electrode and the second electrode.