Formation of novel DRAM cell capacitors by integration of capacitors with isolation trench sidewalls

摘要

A DRAM cell capacitor is described. Capacitor formation and cell isolation methods are integrated by using existing isolation trench sidewalls to form DRAM capacitors. A doped silicon substrate adjacent to the vertical sidewalls of the isolation trench provides one DRAM cell capacitor plate. The DRAM capacitor also contains a dielectric material that partially covers the interior vertical sidewalls of the isolation trench. A conductive layer covering the dielectric material on the vertical sidewalls of the isolation trench forms the second capacitor plate and completes the DRAM capacitor.