Patent ID: 6500707
Filing Date: 2002-12-31
Classification: H01L

Abstract:
A method of manufacturing a trench capacitor, which comprises the following method steps:providing a substrate with a substrate surface; forming a trench with an upper region, a lower region, and a side wall in the substrate, the upper region being closer to the substrate surface than the lower region; isotropically etching the trench to widen the trench in the upper region and the lower region; conformally depositing a first insulating layer in the trench; etching the first insulating layer with directed etching to form the first insulating layer as a lateral edge web; removing the first insulating layer from the lower region of the trench, thereby forming an insulating collar in the upper region from the first insulating layer, the collar extending into the trench from the substrate surface down to a first sinking depth; forming a capacitor dielectric on the substrate in the lower region of the trench and on the insulating collar in the upper region of the trench; filling the trench with a conductive trench filling; sinking the insulating collar into the trench down to a second sinking depth located between the substrate surface and the first sinking depth, and exposing-the substrate on the side wall of the trench, above the second sinking depth; sinking the conductive trench filling and the capacitor dielectric into the trench down to a third sinking depth located between the first sinking depth and the second sinking depth; selective-epitaxially growing a selective epitaxial layer on the exposed side wall of the trench; and forming an electrical contact between the conductive trench filling and a doping region of a selection transistor.