Method for producing a dynamic random access memory device which includes memory cells having capacitor formed above cell transistor and peripheral circuit for improving shape and aspect ratio of contact hole in the peripheral circuit

摘要

A polycrystal silicon layer is used to a cell plate of a capacitor in a memory cell portion including a plurality of memory cells, and a Si.sub. 3 N.sub.4 film layer is used to form a capacitor above a first transistor in the memory cell. The polycrystal silicon layer and Si. sub.3 N.sub.4 film layer formed above a second transistor in a peripheral circuit are simultaneously removed by an etching method during the same process. Therefore an aspect ratio and a shape of a contact hole in the peripheral circuit are improved, and thus the step coverage of the wiring in the peripheral circuit can be improved.