Method of fabricating capacitors of a memory cell array

摘要

A method of fabricating memory cell storage capacitors that includes isotropic etching to form trenches with curved walls in a planar insulating layer that covers gate electrode structures on a substrate. The walls of the trenches serve both a templates and structural supports for the plates of the storage capacitors. Sequential deposition of a first conformal conductive layer on the walls of the trenches, a conformal dielectric film on the first conductive layer, and a second conformal conductive layer on the dielectric film complete the fabrication of the storage capacitors. The curvature of the plates ensures that the capacitance of the storage capacitors exceeds the capacitance of flat-plate storage capacitors of the same vertical extent which subtend the same lateral area on the surface of the substrate.