A capacitor structure in a semiconductor device includes a semiconductor substrate having a top surface and a bottom surface opposite the top surface, an isolation region having a top surface and a bottom surface, opposite the top surface, the bottom surface of the isolation region being disposed on the top surface of the semiconductor substrate. The capacitor structure also includes a gate terminal structure disposed on the top surface of the isolation region and a diffusion contact structure disposed on the top surface of the isolation region and arranged parallel to the gate terminal structure. In some aspects, the gate terminal structure is connected to a first contact node and the diffusion contact structure is connected to a second contact node, in which the first and second contact nodes form opposing nodes of the capacitor structure.