A method for manufacturing a semiconductor device and a semiconductor device are disclosed. The method comprises forming a trench in a substrate, partially filling the trench with a first semiconductive material, forming an interface along a surface of the first semiconductive material, and filling the trench with a second semiconductive material. The semiconductor device includes a first electrode arranged along sidewalls of a trench and a dielectric arranged over the first electrode. The semiconductor device further includes a second electrode at least partially filling the trench, wherein the second electrode comprises an interface within the second electrode.