A trench capacitor includes a plurality of trenches in a semiconductor substrate. A first polysilicon layer is located within the plurality of trenches and over a top surface of the substrate. The first polysilicon layer is continuous between the plurality of trenches. The trench capacitor further includes a plurality of second polysilicon layers. Each of the second polysilicon layers fills a corresponding trench of the plurality of trenches. The second polysilicon layers each extend to a top surface of the first polysilicon layer.