A manufacture includes a doped layer, a body structure over the doped layer, a trench defined in the doped layer, an insulator partially filling the trench, and a first conductive feature buried in, and separated from the doped layer and the body structure by, the insulator. The doped layer has a first type doping. The body structure has an upper surface and includes a body region. The body region has a second type doping different from the first type doping. The trench has a bottom surface. The first conductive feature extends from a position substantially leveled with the upper surface of the body structure toward the bottom surface of the trench. The first conductive feature overlaps the doped layer for an overlapping distance, and the overlapping distance ranging from 0 to 2 μm.