High-density low voltage non-volatile memory with unidirectional plate-line and bit-line and pillar capacitor
Described is a low power, high-density a 1T-1C (one transistor and one capacitor) memory bit-cell, wherein the capacitor comprises a pillar structure having ferroelectric material (perovskite, improper ferroelectric, or hexagonal ferroelectric) and conductive oxides as electrodes. In various embodiments, one layer of the conductive oxide electrode wraps around the pillar capacitor, and forms the outer electrode of the pillar capacitor. The core of the pillar capacitor can take various forms.
1. A capacitive structure comprises:
a ferroelectric material having an inverted u-shape;
a first conductive oxide inside a gap area of the inverted u-shape, wherein the first conductive oxide abuts inner sidewalls of the hexagonal ferroelectric, wherein the first conductive oxide fully fills the gap area;
a second conductive oxide that abuts outer sidewalls of the ferroelectric material, wherein a portion of the second conductive oxide is coupled to the plate-line;
an insulative material that abuts outer sidewalls of the second conductive oxide, wherein the insulative material includes an oxide of Al; and
a refractive intermetallic material that abuts the first conductive oxide and bottom surfaces of the inverted u-shape of the ferroelectric material.
2. The capacitive structure of claim 1 , wherein the first conductive oxide is part of a structure that comprises a stack of layers of a first material and a second material.
3. The capacitive structure of claim 2 , wherein the first material includes one of: Cu, Co, Ru, Ta, or W, and wherein the second material includes one of: Cu, Co, Ru, Ta, W, TaN, or WN.
4. The capacitive structure of claim 1 , wherein the refractive intermetallic material is a first refractive intermetallic material, and wherein the capacitive structure comprises a second refractive intermetallic material that abuts a sidewall of the second conductive oxide.
5. The capacitive structure of claim 1 , wherein the insulative material further includes Ti.
6. The capacitive structure of claim 1 , wherein the ferroelectric material is one of: a perovskite, a hexagonal ferroelectric, or an improper ferroelectric.
7. The capacitive structure of claim 1 , wherein the ferroelectric material includes one of:
a perovskite which includes one of: LaCoO3, SrCoO3, SrRuO3, LaMnO3, SrMnO3, YBa2Cu3O7, Bi2Sr2CaCu2O8, or LaNiO3;
a hexagonal ferroelectric which includes one of: YMnO3 or LuFeO3; or
a hexagonal ferroelectric of a type h-RMnO3, where R is a rare earth element which includes one of: cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb), or yttrium (Y); or
an improper ferroelectric which includes one of: [PTO/STO]n or [LAO/STO]n, where ‘n’ is between 1 to 100.
8. The capacitive structure of claim 4 , wherein the first refractive inter metallic material or the second refractive inter metallic material include one or more of: Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Ru, Rh, Hf, Re, Os, Ir, Al, Ta, W, or Co.
9. The capacitive structure of claim 1 , wherein the first conductive oxide or the second conductive oxide include oxides of one of:
Ir, Ru, Pd, Ps, or Re when the ferroelectric material is a perovskite;
PtCo, PdCo, or a delafossite structured hexagonal metallic when the ferroelectric material is a hexagonal ferroelectric;
Fe, LiV; or
InTi, and
wherein the refractive intermetallic material includes one of Ni3Al, NiAl3, NiAl, Ni—Ti, Ni—Ga, Ni2MnGa, FeGa, Fe3Ga, borides, or carbides.
10. The capacitive structure of claim 1 , wherein the ferroelectric material is doped with Sc or Mn to control leakage through the ferroelectric material.
11. A method for forming a capacitive structure, the method comprising:
forming a ferroelectric material having an inverted u-shape;
forming a first conductive oxide inside a gap area of the inverted u-shape, wherein the first conductive oxide abuts inner sidewalls of the hexagonal ferroelectric, wherein the first conductive oxide fully fills the gap area;
forming a second conductive oxide that abuts outer sidewalls of the ferroelectric material, wherein a portion of the second conductive oxide is coupled to the plate-line;
forming an insulative material that abuts outer sidewalls of the second conductive oxide, wherein the insulative material includes an oxide of Al; and
forming a refractive intermetallic material abutting the first conductive oxide and bottom surfaces of the inverted u-shape of the ferroelectric material.
12. The method of claim 11 , wherein the first conductive oxide is part of a structure, and wherein forming the structure comprises forming a stack of layers of a first material and a second material.
13. The method of claim 12 , wherein the first material includes one of: Cu, Co, Ru, Ta, or W, and wherein the second material includes one of: Cu, Co, Ru, Ta, W, TaN, or WN.
14. The method of claim 13 , wherein the refractive intermetallic material is a first refractive intermetallic material, and wherein the method further comprises forming a second refractive intermetallic material that abuts a sidewall of the second conductive oxide.
15. The method of claim 11 , wherein the insulative material further includes Ti.
16. The method of claim 11 , wherein the ferroelectric material is one of: perovskite, hexagonal ferroelectric, or improper ferroelectric.
17. The method of claim 11 , wherein the ferroelectric material includes one of:
a perovskite which includes one of: LaCoO3, SrCoO3, SrRuO3, LaMnO3, SrMnO3, YBa2Cu3O7, Bi2Sr2CaCu2O8, or LaNiO3;
a hexagonal ferroelectric which includes one of: YMnO3 or LuFeO3;
hexagonal ferroelectrics of a type h-RMnO3, where R is a rare earth element which includes one of: cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb), or yttrium (Y); or
an improper ferroelectric which includes one of: [PTO/STO]n or [LAO/STO]n, where ‘n’ is between 1 to 100.
18. The method of claim 14 , wherein the first refractive intermetallic material or the second refractive intermetallic material include one or more of: Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Ru, Rh, Hf, Re, Os, Ir, Al, Ta, W, or Co.
19. The method of claim 11 , wherein the first conductive oxide or the second conductive oxide includes oxides of one of:
Ir, Ru, Pd, Ps, or Re when the ferroelectric material is a perovskite;
PtCo, PdCo, or a delafossite structured hexagonal metallic when the ferroelectric material is a hexagonal ferroelectric;
Fe, LiV; or
InTi, and
wherein the refractive intermetallic material includes one of Ni3Al, NiAl3, NiAl, Ni—Ti, Ni—Ga, Ni2MnGa, FeGa, Fe3Ga, borides, or carbides.
20. The method of claim 11 , wherein the ferroelectric material is doped with Sc or Mn to control leakage through the ferroelectric material.
21. A system comprising:
a memory comprising a capacitive structure; and an artificial intelligence (AI) processor coupled to the memory, wherein the capacitive structure comprises:
a ferroelectric material having an inverted u-shape;
a first conductive oxide inside a gap area of the inverted u-shape, wherein the first conductive oxide abuts inner sidewalls of the hexagonal ferroelectric, wherein the first conductive oxide fully fills the gap area;
a second conductive oxide that abuts outer sidewalls of the ferroelectric material, wherein a portion of the second conductive oxide is coupled to the plate-line;
an insulative material that abuts outer sidewalls of the second conductive oxide, wherein the insulative material includes an oxide of AI; and
a refractive intermetallic material that abuts the first conducive conductive oxide and bottom surfaces of the inverted u-shape of the ferroelectric material.
22. The system of claim 21 , wherein the ferroelectric material is one of: perovskite, hexagonal ferroelectric, or improper ferroelectric.
23. The system of claim 21 , wherein the ferroelectric material includes one of:
a perovskite which includes one of: LaCoO3, SrCoO3, SrRuO3, LaMnO3, SrMnO3, YBa2Cu3O7, Bi2Sr2CaCu2O8, or LaNiO3;
a hexagonal ferroelectric which includes one of: YMnO3 or LuFeO3;
hexagonal ferroelectrics of a type h-RMnO3, where R is a rare earth element which includes one of: cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb), or yttrium (Y); or
an improper ferroelectric which includes one of: [PTO/STO]n or [LAO/STO]n, where ‘n’ is between 1 to 100.
24. The capacitive structure of claim 1 , wherein the insulative material has a lattice parameter which is substantially matched with a lattice parameter of the first conductive oxide.