HIGHLY INTEGRATED SEMICONDUCTOR MEMORY DEVICE WITH TRENCH CAPACITORS AND STACKED CAPACITORS

摘要

A highly integrated semiconductor memory device comprises a plurality of memory cells formed by alternately disposing a stack-type capacitor cell and a combined stack-trench type capacitor cell both in row and column directions. Each storage electrode of the capacitor of the memory cell is extended to overlap with the storage electrode of the capacitor of the adjacent memory cell. The combined stack-trench type capacitor is formed into the substrate to increase the storage capacitance thereof which allow the storage capacitance of the stack-type capacitor to increase by extending the storage electrode of the capacitor. Due to the alternate arrangement of stack-trench type capacitor and stack-type capacitor, step coverage, leakage current and soft errors of stack-trench type capacitor are prevented.