US 4,543,597 AGranted

Dynamic semiconductor memory and manufacturing method thereof

AssigneeTokyo Shibaura Denki Kabushiki Kaisha

InventorTadashi Shibata

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Abstract

A method to prevent dielectric breakdown of a thin gate insulating film of a memory cell capacitor of a dynamic semiconductor memory device such as a dynamic random access memory during fabrication of the memory. A diffusion layer of an n-conductivity type is formed on a predetermined surface region of a semiconductor substrate of a p-conductivity type so as to form a p-n junction. Then, there is formed a polycrystalline semiconductor layer which corresponds to a gate electrode and which is connected to the thin gate insulating film and partially contacts the diffusion layer. Thus the polycrystalline semiconductor layer is electrically connected to the substrate through a diode region which is formed of the p-n junction. The polycrystalline semiconductor layer is then etched in a reactive ion etching step, and any abnormal charges stored in the thin gate insulation layer during the reactive etching step are immediately discharged to the substrate.

Claims24

Dependent claims

A method of manufacturing a dynamic semiconductor memory device having a plurality of memory cells each of which has a capacitor element, said method comprising the steps of:

forming an electrically insulative film on a semiconductive substrate of a first conductivity type, said electrically insulative film being used for a dielectric body of said capacitor element of each of said memory cells and having an opening exposing a portion of the surface of said substrate;
forming an electrically conductive layer on said insulative film and on said exposed portion of the surface of said substrate, said conductive layer corresponding to a gate electrode;
and
performing a reactive ion etching step on said conductive layer while maintaining an electric contact between said conductive layer and said substrate through said opening, whereby charges produced by the reactive ion etching and stored in said insulative film are removed to said substrate via said conductive layer, thereby preventing an increase in an electric field within said insulative film and preventing damage to said insulative film due to an electrostatic dielectric breakdown.

1 more element

Dependencies are inferred from the claim text.