Patent ID: 8637367

Claim:
A method for producing an insulation layer between a first electrode and a second electrode in a trench of a semiconductor body, the method comprising: providing a semiconductor body with a trench formed therein, wherein a first electrode is formed in a lower part of the trench; producing a first insulation layer having a first thickness on the first electrode and at the sidewalls of the trench in an upper part of the trench in such a way that the insulation layer is formed in a U-shaped fashion in the trench; producing a protective layer having a width substantially equal to a width of the first electrode on the insulation layer; removing the insulation layer at the sidewalls of the trench in an upper part of the trench above the lower surface of the protective layer; removing the protective layer; producing a second insulating layer having a second thickness being less than said first thickness only on the sidewalls of the trench; and producing a second electrode at least on the first and second insulation layers above the first electrode.