Two bit u-shaped memory structure and method of making the same
AssigneeNanya Technology Corporation
InventorsWei-Ming Liao, Jer-Chyi Wang
Life of this patent
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Abstract
A memory structure includes: a substrate; a control gate positioned on the substrate; floating gates positioned at two sides of the control gate, wherein the floating gates have a U-shaped bottom embedded in the substrate; a first dielectric layer positioned between the control gate and the substrate; a second dielectric layer positioned between the U-shaped bottom of the floating gates and the substrate; a third dielectric layer positioned between the control gate and the floating gates; a local doping region positioned around the floating gates channel; and a source/drain doping region positioned in the substrate at a side of the floating gates.
Claims12
A memory structure comprising:
- a substrate;
- a control gate positioned on the substrate;
- a plurality of floating gates positioned at two sides of the control gate, wherein each of the floating gates has a U-shaped bottom embedded in the substrate;
- a U-shaped floating gate channel positioned around the bottom of the floating gates;
- a first dielectric layer positioned between the control gate and the substrate;
- a second dielectric layer positioned between the U-shaped bottom of the floating gates and the substrate;
- a third dielectric layer positioned between the control gate and the floating gates;
- a local doping region positioned around the U-shaped floating gate channel;
- and
- a source/drain doping region positioned in the substrate at a side of the floating gates.
A method of fabricating a memory structure, comprising:
- providing a substrate comprising a first trench and a second trench positioned in the substrate;
- forming a local doping region in the bottom of the first trench and the second trench;
- forming a first dielectric layer covering the surface of the first trench, the surface of the second trench and the surface of the substrate;
- forming a first conductive layer covering and filling up the first trench and the second trench;
- forming a second dielectric layer at two sides of the first conductive layer;
- forming an opening in the first conductive layer between the first trench and the second trench;
- and
- forming a doping region positioned in the substrate between the first trench and the second trench.
Dependencies are inferred from the claim text.