Capacitor comprising anti-ferroelectric layers and high-k dielectric layers
A semiconductor device includes a first electrode, a second electrode, and a multi-layer stack positioned between the first electrode and the second electrode, the multi-layer stack including at least one anti-ferroelectric layer and at least one high-k dielectric layer.
1. A semiconductor device comprising:
a capacitor, wherein the capacitor includes:
a first electrode;
a second electrode; and
a high band gap layer disposed between the first electrode and the second electrode;
a first high-k dielectric layer disposed between the first electrode and the high band gap layer;
a first anti-ferroelectric layer disposed between the high band gap layer over the first high-k dielectric layer;
a second high-k dielectric layer disposed between the second electrode and the high band gap layer; and
a second anti-ferroelectric layer disposed between the high band gap layer and the second high-k dielectric layer,
wherein the first and second anti-ferroelectric layers have a tetragonal crystal structure,
wherein the first and second anti-ferroelectric layers include a hafnium oxide-rich hafnium zirconium oxide whose hafnium oxide content is greater than a zirconium oxide content,
wherein the high band gap layer is formed of a single layer of an aluminum-containing material and is directly contacted with the first and second anti-ferroelectric layers, and
wherein the first and second high-k dielectric layers include zirconium oxide.
2. The semiconductor device of claim 1 , wherein the first and second anti-ferroelectric layers include an anti-ferroelectric hafnium zirconium oxide.
3. The semiconductor device of claim 1 , wherein the first and second anti-ferroelectric layers have a thickness which is thinner than approximately 30 Å.
4. The semiconductor device of claim 1 , wherein the hafnium oxide-rich hafnium zirconium oxide has a thickness which is thinner than approximately 30 Å.
5. The semiconductor device of claim 1 , wherein the high band gap layer has an energy band gap greater than the first and second anti-ferroelectric layers and the first and second high-k dielectric layers.
6. The semiconductor device of claim 1 , further includes:
a leakage blocking layer between the second high-k dielectric layer and the second electrode; and
an interface control layer over the leakage blocking layer.
7. The semiconductor device of claim 6 , wherein the leakage blocking layer includes a material having a lower dielectric constant and a higher energy band gap than the first and second anti-ferroelectric layers and the first and second high-k dielectric layers.
8. The semiconductor device of claim 6 , wherein the interface control layer includes a material having a greater electronegativity than the first and second anti-ferroelectric layers and the first and second high-k dielectric layers.
9. The semiconductor device of claim 1 , further comprising:
a semiconductor substrate;
a transistor including a buried word line structure formed in the semiconductor substrate, and a first source/drain region and a second source/drain region on both sides of the buried word line structure; and
a bit line coupled to the first source/drain region of the transistor,
wherein the first electrode is coupled to the second source/drain region of the transistor.
10. The semiconductor device of claim 1 , wherein the first and second high-k dielectric layers have a tetragonal crystal structure.
11. The semiconductor device of claim 1 , wherein the high band gap layer includes aluminum oxide, aluminum-doped zirconium oxide or aluminum-doped hafnium oxide.