Semiconductor memory device and its fabricating method

  • US 5,144,579 A
  • Filed: 09/07/1990
  • Issued: 09/01/1992
  • Est. Priority Date: 09/08/1989
  • Status: Expired due to Term
First Claim
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1. A semiconductor memory device comprising:

  • a MOSFET including a gate electrode and source and drain regions of a second electrical conductivity type impurity material formed in a surface of a semiconductor substrate of a first electrical conductivity type material;

    a bit line connected to one of the source and drain regions of said MOSFET through a bit line contact hole made in an insulating film covering the surface of said substrate on which the MOSFET is formed; and

    a capacitor including a storage node electeode formed over a region where said MOSFET is formed, a capacitor insulating film and a plate electrode sequentially formed on said storage node electrode layer to be connected to another of said source and drain regions through a storage node contact hole made in said insulating film,wherein at least one of said storage node contact hole and bit line contact hole includes a first contact hole made in a first inter-layer insulating film formed over said gate electrode and a second contact hole made in a second inter-layer insulating film formed over an electrically conductive layer embedded in said first contact hole up to a level higher than the gate electrode such as to be contacted with said electrically conductive layer.

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