Patent ID: 6423607
Filing Date: 2002-07-23
Classification: H01L

Abstract:
A method for fabricating a trench capacitor, which comprises the following steps:forming a trench with trench walls, a lower region, and an upper region, in a substrate having a region serving as a first capacitor plate; forming of a first dielectric layer constituting a capacitor dielectric on the trench walls; filing the lower region of the trench with a filling material, the filling material constituting a second capacitor plate; forming an insulation collar in the upper region of the trench on the first dielectric layer; filling the upper region of the trench with filling material and sinking the filling material below the substrate surface; selectively removing part of the insulation collar and of the first dielectric layer located laterally next to the insulation collar in the upper region of the trench; forming an insulation trench in a first trench half on the insulation collar and the filling material in the upper region of the trench, and during the formation of the insulation trench, removing a part of the insulation collar and of the first dielectric layer located laterally next to the insulation collar in the upper region of the trench; filling the insulation trench with a dielectric; and forming a capacitor connection region in a second trench half on the insulation collar and the filling material in the upper region of the trench, and, during the formation of the capacitor connection region, removing a part of the insulation collar and of the first dielectric layer located laterally next to the insulation collar in the upper region of the trench as well as a part of the dielectric of the insulation trench.