NROM memory device with a high-permittivity gate dielectric formed by the low temperature oxidation of metals
AssigneeMicron Technology, Inc.
InventorLeonard Forbes
Life of this patent
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Abstract
A high permittivity gate dielectric formed by low temperature metal oxidation is used in an NROM memory cell. The gate dielectric has a dielectric constant greater than silicon dioxide and is comprised of a nanolaminate structure. The NROM memory cell has a substrate with doped source/drain regions. The high-k gate dielectric is formed above the substrate. A polysilicon control gate is formed on top of the gate dielectric. The gate dielectric may have an oxide—high-k dielectric—oxide composite structure or an oxide oxide—high-k dielectric composite structure.
Claims11
An electronic system comprising:
- a processor that generates control signals;
- and
- a memory array coupled to the processor, the array comprising a plurality of NROM memory transistors, each NROM memory transistor comprising:
- a substrate having a plurality of source/drain regions, the source/drain regions having a different conductivity type than the remainder of the substrate;
- a nanolaminate, high permittivity (high-k), oxidized metal gate dielectric overlying the substrate, the gate dielectric composed of oxide-oxidized Aluminum-oxide;
- and
- a control gate formed on top of the gate dielectric;
- wherein the oxidized Aluminum has a first concentration of excess Aluminum at a first oxide interface adjacent the substrate and a second concentration of excess Aluminum at a second oxide interface adjacent the control gate;
- and
- wherein the first concentration of excess Aluminum is greater than the second concentration of excess Aluminum.
An NROM memory transistor comprising:
- a substrate having a plurality of source/drain regions, the source/drain regions having a different conductivity type than the remainder of the substrate;
- a nanolaminate, high permittivity (high-k), oxidized metal gate dielectric overlying the substrate, the gate dielectric composed of oxide-oxidized Aluminum-oxide;
- and
- a control gate formed on top of the gate dielectric;
- wherein the oxidized Aluminum has a first concentration of excess Aluminum at a first oxide interface adjacent the substrate and a second concentration of excess Aluminum at a second oxide interface adjacent the control gate;
- and
- wherein the first concentration of excess Aluminum is greater than the second concentration of excess Aluminum.
Dependencies are inferred from the claim text.