Patent ID: 6255682
Filing Date: 2001-07-03
Classification: H01L

Abstract:
Trench capacitors with self-aligned field plate formed in a substrate, said substrate having trenches formed therein, said trench capacitors comprising:a recess region formed adjacent to the top portion of the openings of said trenches and on the top portion between said trenches;a first isolation layer formed on said substrate and on a surface of said recess region;a second isolation layer formed on said first isolation layer on a portion of said recess region between said trenches, wherein a bottom surface of said second isolation layer is lower than a top surface of said substrate;a dielectric layer serving as a capacitor dielectric formed along a surface of said sidewalls of said trenches, said first isolation layer, and on a surface of said second isolation layer;a sidewall spacer structure formed on a upper portion of said sidewalls of said trenches, which is also refilled in said recess;a first storage node formed in said substrate surrounding sidewalls of said trenches under said recess;a second storage node formed in said trenches, and a portion of said second storage node formed over said dielectric layer between said trenches to act as a field plate of said trenches capacitor; anda third isolation layer formed on said field plate.