Capacitor structures for dynamic random access memory cells

摘要

A three dimensional capacitor structure particularly adapted for use as a memory cell capacitor of a DRAM is disclosed. The capacitor structure incorporates the substantially vertical (in relation to the substrate) sides of a plurality of spacers into the storage node capacitor to increase the total area of the storage node capacitor. In the described embodiments of the invention, a first spacer and a second spacer are formed next to the digit lines. The bottom storage node plate is formed on at least the first sides of the spacers to increase area of the storage node. The bottom storage node plate is also formed on the upper surface of the digit line. Additional spacers can also be added to further increase the area of the storage node. A dielectric layer is formed over the first capacitor plate and a second capacitor plate layer is formed over the dielectric layer to complete the structure.