An integrated circuit device having a capacitor structure and methods of manufacture are disclosed. The device has a substrate, e.g., silicon wafer, silicon on insulator, epitaxial wafer. The device has a dielectric layer overlying the substrate and a polysilicon layer overlying the dielectric layer. The device has a tungsten silicide layer overlying the polysilicon layer and a first oxide layer overlying the tungsten silicide layer. A nitride layer overlies the oxide layer. A second oxide layer is overlying the nitride layer to form a sandwiched oxide on nitride on oxide structure to form a capacitor dielectric. The device also has an upper capacitor plate formed overlying the second oxide layer.