Nonvolatile memory device and method for fabricating the same
AssigneeHynix Semiconductor Inc.
InventorJae-Hong Kim
Life of this patent
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Abstract
A nonvolatile memory device includes a control gate formed along a first direction over a substrate, an active region formed over the substrate, the active region being defined along a second direction crossing the control gate and including a fin type protruding portion having rounded top corners at a region where the control gate and the active region overlap, a floating gate formed over a surface of the protruding portion of the active region below the control gate and formed to a substantially uniform thickness along the surface profile of the protruding portion of the active region, a tunneling insulation layer formed between the floating gate and the active region, and a dielectric layer formed between the floating gate and the control gate.
Claims24
A nonvolatile memory device, comprising:
- a control gate formed along a first direction over a substrate;
- an active region formed over the substrate, the active region being defined along a second direction crossing the control gate and including a fin type protruding portion having rounded top corners at a region where the control gate and the active region overlap;
- a floating gate formed over a surface of the protruding portion of the active region below the control gate and formed to a substantially uniform thickness along the surface profile of the protruding portion of the active region;
- a tunneling insulation layer formed between the floating gate and the active region;
- and
- a dielectric layer formed between the floating gate and the control gate.
A method for fabricating a nonvolatile memory device, comprising:
- forming isolation structures to define active regions;
- recessing portions of the isolation structures so that the active regions protrude above the isolation structures;
- rounding top corners of the protruding active regions;
- forming tunneling insulation layers over surfaces of the protruding active regions;
- forming floating gate layers to a substantially uniform thickness over the tunneling insulation layers along the surface profile of the protruding active regions;
- forming a dielectric layer and a control gate layer over a substrate structure;
- forming gate masks over the control gate layer along a direction crossing the active regions;
- and
- etching the control gate layer, the dielectric layer, the floating gate layers, the tunneling insulation layers, and the protruding active regions using the gate masks, exposing the recessed isolation structures, to form protruding fin type active regions and form gates over the protruding fin type active regions,
- wherein etching the control gate layer, the dielectric layer, the floating gate layers, the tunneling insulation layers, and the protruding active regions to form the gates comprises:
- forming a silicon oxynitride (SiON) layer over the control gate layer;
- forming a hard mask layer over the SiON layer;
- forming a control gate mask over the hard mask layer;
- patterning the hard mask layer;
- and
- etching the SiON layer, the control gate layer, the dielectric layer, the floating gate layers, the tunneling insulation layers, and the protruding active regions using the patterned hard mask layer.
Dependencies are inferred from the claim text.