Patent ID: 6777303
Filing Date: 2004-08-17
Classification: H01L

Abstract:
A method of fabricating an insulation collar in a trench capacitor, which comprises the steps of:a) providing a semiconductor substrate; b) forming a trench in the semiconductor substrate; c) forming an insulating layer in the trench in order to form an insulation collar; d) subsequently filling a lower region of the trench, the lower region extending up to a predetermined height, with a sacrificial filling material, so that an upper region of the trench, the upper region extending above the predetermined height, remains uncovered by the sacrificial filling material; e) after step d) forming a patterning layer that is relatively thin in comparison with the insulating layer on the insulating layer and on the sacrificial filling material in the trench; f) forming an opening in the patterning layer toward the sacrificial filling material, the patterning layer remaining on the insulating layer in the upper region of the trench; g) subsequently removing the sacrificial filling material from the trench; and h) subsequent to step g), removing the insulating layer from the lower region of the trench by etching the insulating layer selectively with respect to the patterning layer, so that the insulation collar is produced in the upper region of the trench.