NROM flash memory with a high-permittivity gate dielectric
OwnerLeonard Forbesinventor
Life of this patent
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Abstract
A high permittivity gate dielectric is used in an NROM memory cell. The gate dielectric has a dielectric constant greater than silicon dioxide and is comprised of an atomic layer deposited and/or evaporated nanolaminate structure. The NROM memory cell has a substrate with doped source/drain regions. The high-k gate dielectric is formed above the substrate between a pair of the source/drain regions. A polysilicon control gate is formed on top of the gate dielectric. The gate dielectric can have an oxide-high-k dielectric-oxide composite structure, an oxide-nitride-high-k dielectric composite structure, or a high-k dielectric-high-k dielectric-high-k dielectric composite structure.
Claims6
A method for fabricating an NROM memory cell, the method comprising:
- creating a plurality of source/drain regions by doping portions of a substrate;
- forming a nanolaminate gate dielectric layer on the substrate substantially between the plurality of source/drain regions, wherein forming the gate dielectric layer comprises forming one of the following structures:
- oxide-HfO2-oxide, oxide-ZrO2-oxide, oxide-ZrSnTiO-oxide, oxide-ZrON-oxide, oxide-ZrAlO-oxide, oxide-ZrTiO4-oxide, oxide-Al2O3-oxide, oxide-La2O3-oxide, oxide-LaAlO3-oxide, oxide-HfAlO3-oxide, oxide-HfSiON-oxide, oxide-Y2O3-oxide, oxide-Gd2O-oxide, oxide-Ta2O5-oxide, oxide-TiO2-oxide, oxide-Pr2O3-oxide, oxide-CrTiO3-oxide, or oxide-YSiO-oxide;
- and
- forming a gate on the gate dielectric layer;
- wherein forming the nanolaminate gate dielectric layer on the substrate comprises forming a first oxide layer on the substrate, forming a metal layer on the first oxide layer, converting the metal layer to a dielectric form and forming a second oxide layer on the metal layer after converting it to its dielectric form.
Dependencies are inferred from the claim text.