Dynamic random access memory cell - has insulating film on word-line, covered by conductive layer, insulating layer and bit-line formed on insulating layer

摘要

The DRAM cell insulating film (7) is formed on a word line (4). The film is covered by a conductive layer (8) as a protection against capacitive coupling between the word and bit lines. The conductive layer is covered by a second insulating film (9). The latter supports a bit line (12) such that the potential of the word line is not affected by a transient signal applied to the bit line. Pref. the conductive layer may be under a preset potential of specified value, or as earth potential. The conductive layer typically consists of polycrystalline or amorphous silicon. In the mfr. of the cell the bit line and the memory electrode are coupled to a source or drain region of a MOSFET respectively. ADVANTAGE - Prevention of capacitive coupling between the word and the bit lines.