Semiconductor device especially DRAM production

摘要

A semiconductor device production process involves (a) successively forming a first insulation layer (5), a first conductive layer (8) and a silicon oxide layer (9) on a silicon substrate; (b) patterning the silicon oxide layer (9) and the first conductive layer (8) to form gate electrodes (8) with silicon oxide covered top surfaces; (c) doping the substrate between adjacent gate electrodes (8) to form active regions (10a, b); (d) forming a silicon nitride layer (11) over the entire surface; (e) forming a second insulation layer (14) on the silicon nitride layer (11); (f) forming vias in the second insulation layer (14) between selected adjacent gate electrodes; and (g) extending the vias down to the silicon nitride layer (11) formed on the first insulation layer (5) and down to the first insulation layer (5) between the silicon nitride layers (11) formed on the side surfaces of the adjacent gate electrodes (8) in order to form contacts (18, 21) to the selected active regions (1 0a, b). Also claimed are similar processes in which the silicon nitride layer (11) is anisotropically etched to form silicon nitride side walls (11a) on the gate electrode side surfaces before forming the second insulation layer (14) and in which the substrate has a memory cell forming section (A) and a peripheral circuit forming section (B). Further claimed are the resulting semiconductor devices.