Nonvolatile semiconductor memory device and method of producing the same
AssigneeNippon Steel Corporation
InventorYasuo Sato
Life of this patent
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Abstract
In a nonvolatile semiconductor memory device and a method of producing the same, the nonvolatile semiconductor memory device includes a semiconductor substrate of a first conductivity type, a pair of spaced source/drain diffusion layers of a second conductivity type different from the first conductivity type, a floating gate electrode formed on a channel region disposed between the pair of source/drain diffusion layers in the surface of the semiconductor substrate in an insulated relationship with the channel region, and a control gate electrode formed on the floating gate electrode in on insulated relationship with the floating gate electrode wherein a part of the control gate electrode to extend beyond a side of the floating gate electrode to an underside thereof.
Claims10
A method of producing a nonvolatile semiconductor memory device comprising the steps of:
- selectively forming element isolation insulating films in a surface of a semiconductor substrate;
- forming a first polycrystalline silicon film over the surface of said semiconductor substrate;
- selectively etching said first polycrystalline silicon film to thereby partially expose said element isolation insulating films;
- partially etching each of said element isolation insulating films using said first polycrystalline silicon film as a mask to form a gap between a portion of each of said element isolation insulating films underlying said first polycrystalline silicon film and said first polycrystalline silicon film;
- and
- successively forming an interlayer insulating film and a second polycrystalline silicon film over an entire surface of said semiconductor substrate to form said nonvolatile memory device.
A method of manufacturing a nonvolatile semiconductor memory device comprising the steps of:
- selectively forming element isolation insulating films in a surface of a semiconductor substrate;
- forming a first conductive film over the surface of said semiconductor substrate;
- selectively etching said first conductive film to partially expose each of said element isolation insulating films;
- partially etching each of said element isolation insulating films using said first conductive film as a mask to form a gap between a portion of each of said element isolation insulating films underlying said first conductive film and said first conductive film;
- and
- forming successively an interlayer insulating film and a second conductive film over an entire surface of said semiconductor substrate to form said nonvolatile memory device.
Dependencies are inferred from the claim text.