CMOS Dynamic RAM cell and method of fabrication
AssigneeIntel Corporation
InventorsMark T. Bohr, Kenneth K. Yu, Ronald J. C. Chwang, Neil C. Berglund
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Abstract
A high density CMOS dynamic RAM cell comprising a transistor and capacitance means formed in an n-well is disclosed. The capacitance means includes a polysilicon plate member disposed above a p-type region formed in the n-well. A buried contact, extending from the plate member, pierces the p-type region and contacts the well. In addition to the capacitance associated with the plate member, p-type region and well, capacitance is obtained between the side walls of the n-type regions and p-type regions.
Claims8
A metal-oxide-semiconductor, dynamic memory cell, disposed in an n-type well on a p-type silicon substrate comprising:
- a transistor;
- a capacitor coupled to said transistor for storing charge comprising:
- a plate member disposed above said well with an insulating layer disposed between said plate member and said well;
- a p-type region disposed within said well below said plate member;
- an n-type buried contact region disposed within said p-type region, said n-type region extending into said well for coupling said plate member to said well;
- whereby a high density dynamic memory cell is realized which has high immunity to failures associated with alpha particles.
A pair of CMOS dynamic memory cells found in an n-type well comprising:
- a first and second p-channel transistor;
- a p-type region disposed in said well;
- an n-type region disposed through said p-type region into contact with said well, separating said p-type region into a first and a second p-type region;
- said first region being coupled to said first transistor and said second region being coupled to said second transistor;
- a plate member disposed over said p-type region, said member contacting said n-type region;
- whereby said plate member along with said first and second regions form capacitance storage means for said cells, and wherein additional storage capacitance is formed by the junctions between said n-type region and said first and second regions.
Dependencies are inferred from the claim text.