Patent ID: 6319788
Filing Date: 2001-11-20
Classification: H01L

Abstract:
A method for fabricating a trench capacitor comprising:forming a bottle-shaped trench in the substrate, such trench having a diameter in a lower portion thereof greater than in an upper portion of the trench;depositing a sacrificial material to line walls of the trench with the sacrificial material having a substantially uniform thickness over sidewalls of the trench, and with such sacrificial material being deposited such that the trench is void of the material in an inner region of the trench;forming a dielectric collar in an upper portion of the trench above the sacrificial material;removing the sacrificial material from the lower portion of the trench;forming a node dielectric that lines the collar and trench sidewalls at the bottom region of the trench; andfilling the trench with an electrically conductive material, such electrically conductive material providing an electrode of the trench capacitor.