Patent ID: 6825079
Filing Date: 2004-11-30
Classification: H01L

Abstract:
A method for producing a horizontal insulation layer, which comprises the steps of:providing a semiconductor substrate having a surface, a trench formed therein, and at least one layer containing a material selected from the group consisting of silicon nitride and silicon oxide disposed on the surface of the semiconductor substrate, the trench having an upper region with uncovered sidewalls and a lower region filled with a conductive material as far as a first depth below the surface of the semiconductor substrate forming a conductive layer; depositing an insulating material onto the semiconductor substrate forming an insulation layer in the trench, a surface of the insulation layer being at a first distance from the sidewalls of the trench and at a second distance from the conductive layer, the first distance being smaller than the second distance, the insulating material being deposited such that the trench is filled as far as a second depth, which lies below a surface of the layer containing the silicon nitride or the silicon oxide; removing the insulating material disposed on the layer containing the silicon nitride or the silicon oxide; and performing an isotropic etching of the insulating material of the insulation layer until an amount of the insulating material removed from the surface of the insulation layer being greater than the first distance and less than the second distance, and that the insulation layer being removed from the sidewalls of the trench resulting in the insulating layer being a horizontal insulation layer with a given thickness remaining on the conductive layer.