Patent ID: 7816210

Claim:
A method for producing a trench transistor, the method comprising: providing a semiconductor body including a first side and a second side; producing at least one first trench and at least one second trench, the at least one first trench and at least one second trench arranged spaced apart from one another and extending into the semiconductor body starting from the first side of the semiconductor body; applying a first dielectric layer to exposed surfaces of the at least one first trench and the at least one second trench; filling the at least one first trench and the at least one second trench up to the same height with an electrode material; partially removing the electrode material from the at least one first trench and the at least one second trench by applying an etching process in which an etching agent acts on the electrode material for a predetermined etching period, the etching process resulting in a first field electrode in the at least one first trench and a second field electrode in the at least one second trench; and producing a first gate electrode in the at least one first trench above the first field electrode and a second gate electrode in the at least one second trench above the second field electrode, the first gate electrode and the second gate electrode insulated from the semiconductor body by a gate dielectric layer; wherein the at least one first trench defines a first trench width in a lateral direction of the semiconductor body, and wherein the at least one second trench defines a second trench width in the lateral direction of the semiconductor body, the first trench width wider than the second trench width such that, during the etching process, the electrode material in the at least one first trench is etched deeper relative to the first side of the semiconductor body than in the at least one second trench.