A semiconductor and method for manufacturing a semiconductor device. In one embodiment the method includes providing a semiconductor substrate with a first substrate surface and at least one trench having at least one trench surface. The trench extends from the first substrate surface into the semiconductor substrate. The trench has a first trench section and a second trench section. The trench surface is exposed in an upper portion of the first and second trench sections and covered with a first insulating layer in a lower portion. A second insulating layer is formed at least on the exposed trench surface in the upper portion. A conductive layer is formed on the second insulating layer at least in the upper portion, wherein the second insulating layer electrically insulates the conductive layer from the semiconductor substrate. The conductive layer is removed in the first trench section without removing the conductive layer in the second trench section.