Nonvolatile memory device including ferroelectric layer having negative capacitance
A nonvolatile memory device according to an aspect of the present disclosure includes a substrate having a channel layer, a gate dielectric layer structure disposed on the channel layer, a ferroelectric layer disposed on the gate dielectric layer structure, and a gate electrode layer disposed on the ferroelectric layer. The gate dielectric layer structure has a positive capacitance. The ferroelectric layer has a negative capacitance. The gate dielectric layer structure includes a charge tunneling layer, a charge trap layer and a charge barrier layer disposed on the channel layer.
1. A nonvolatile memory device comprising:
a substrate having a channel layer;
a gate dielectric layer structure disposed on the channel layer;
an internal voltage amplification layer disposed on the gate dielectric layer structure; and
a gate electrode layer disposed on the internal voltage amplification layer,
wherein the gate dielectric layer structure has a positive capacitance,
wherein the internal voltage amplification layer is a ferroelectric layer having a negative capacitance,
wherein the gate dielectric layer structure comprises a charge tunneling layer, a charge trap layer and a charge barrier layer disposed on the channel layer,
wherein the nonvolatile memory device has an operation gate voltage corresponding to a polarization switching voltage of the internal voltage amplification layer,
wherein when the operation gate voltage is applied to the gate electrode layer, an internal voltage greater than the operation gate voltage is applied to the gate dielectric layer structure.
2. The nonvolatile memory device of claim 1 ,
wherein each of the charge tunneling layer, the charge trap layer and the charge barrier layer is a paraelectric layer.
3. The nonvolatile memory device of claim 2 ,
wherein the charge tunneling layer comprises silicon oxide,
wherein the charge trap layer comprises silicon nitride, and
wherein the charge barrier layer comprises silicon oxide.
4. The nonvolatile memory device of claim 1 ,
wherein the internal voltage amplification layer comprises at least one selected from the group consisting of hafnium oxide, zirconium oxide, and hafnium zirconium oxide.
5. The nonvolatile memory device of claim 1 ,
wherein the internal voltage amplification layer is disposed to interface with the charge barrier layer.
6. The nonvolatile memory device of claim 1 ,
wherein the gate dielectric layer structure and the internal voltage amplification layer are electrically connected to each other in series between the gate electrode layer and the channel layer.
7. The nonvolatile memory device of claim 6 ,
wherein an absolute value of a capacitance of the internal voltage amplification layer is greater than an absolute value of a capacitance of the gate dielectric layer structure.
8. The nonvolatile memory device of claim 1 ,
wherein the substrate comprises at least one selected from the group consisting of silicon (Si), germanium (Ge), silicon germanium (SiGe), gallium arsenide (GaAs), and indium phosphide (InP).
9. The nonvolatile memory device of claim 1 , further comprising:
a source region and a drain region that are disposed in substrate regions of different ends of the channel layer.