Production of a trench capacitor comprises a preparing a substrate having a surface in which a trench is formed and having an upper region, a lower region and a side wall

摘要

Production of a trench capacitor comprises a preparing a substrate having a surface in which a trench is formed and having an upper region, a lower region and a sidewall; inserting a dopant through the trench side wall in the lower region of the trench. Method also involves forming a mask layer on the trench side wall of the lower region of the trench; depositing nanocrystals on the mask layers so that the crystals cover a first part of the mask layer and expose a second part of the mask layer; etching the mask layer to expose the trench side wall; etching the substrate in the lower region of trench using a structured mask layer; removing the structured mask layer (110) by etching; forming an insulation layer on the trench side wall; depositing a conducting trench filling in the trench on the insulation layer as inner capacitor electrode; and forming a transistor which is connected to the conducting trench filling to control the trench capacitor. Preferred Features: An insulation collar is produced in the upper region of the trench on the side wall before the side wall is roughened. The mask layer is formed using LPCVD nitride deposition.