Patent ID: 7375029
Filing Date: 2008-05-20
Classification: H01L

Abstract:
1. A method for fabricating contact holes in a semiconductor body, the semiconductor body including a structure comprising a plurality of trenches, each trench of the plurality of trenches being isolated from other trenches of the plurality of trenches by mesa regions, each trench of the plurality of trenches including an electrode electrically insulated from the semiconductor body by a first insulation layer, an upper end of the electrode being situated at a deeper level than an upper end of the corresponding trench, the method comprising: producing a second insulation layer, which covers at least parts of a surface of the structure, by subjecting the surface of the structure to a thermal oxidation process; depositing a third insulation layer on the second insulation layer after the formation of the second insulation layer; carrying out a CMP or an etching planarization process in such a way that the semiconductor body is uncovered in at least portions of the mesa regions, and whereby parts of the second insulation layer or of the third insulation layer are removed; and forming the contact holes in the mesa regions by using residues of the second insulation layer that have remained after the planarization process as a contact hole mask.