Oxide based memory
Methods, devices, and systems associated with oxide based memory are described herein. In one or more embodiments, a method of forming an oxide based memory cell includes forming a first electrode, forming a tunnel barrier, wherein a first portion of the tunnel barrier includes a first material and a second portion of the tunnel barrier includes a second material, forming an oxygen source, and forming a second electrode.
1. A method of forming an oxide based memory cell, comprising:
forming a first electrode;
forming an oxygen source, wherein a first number of oxygen ions are present in the oxygen source;
forming a tunnel barrier, wherein the tunnel barrier includes a first portion formed of a first material, a second portion formed of a second material that is different from the first material, a third portion formed of the first material, and a fourth portion formed of the second material, wherein the first portion is between the oxygen source and the second portion, the second portion is between the first portion and the third portion, the third portion is between the second portion and the fourth portion, and wherein a second number of oxygen ions from the oxygen source are present in the first, second, third, and fourth portions of the tunnel barrier;
and forming a second electrode, wherein the fourth portion is between the third portion and the second electrode.
2. The method of claim 1 , wherein forming the tunnel barrier includes forming the first and third portions with aluminum oxide and forming the second and fourth portions with hafnium oxide.
3. The method of claim 1 , wherein the method includes forming the tunnel barrier and the oxygen source via atomic layer deposition (ALD).
4. The method of claim 1 , wherein the method includes forming the tunnel barrier and the oxygen source via chemical vapor deposition (CVD).
5. The method of claim 1 , wherein forming the tunnel barrier includes forming the first and third portions such that the first and third portions have an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the second and fourth portions.
6. The method of claim 1 , wherein forming the tunnel barrier includes forming the first portion such that the first portion has an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the third portion.
7. The method of claim 1 , wherein forming the tunnel barrier includes forming the second portion such that the second portion has an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the fourth portion.
8. A memory cell, comprising:
a first electrode;
an oxygen source, wherein the oxygen source includes a first number of oxygen ions;
a tunnel barrier, wherein the tunnel barrier includes a first portion formed of a first material, a second portion formed of a second material that is different from the first material, a third portion formed of the first material, and a fourth portion formed of the second material, wherein the first portion is between the oxygen source and the second portion, the second portion is between the first portion and the third portion, the third portion is between the second portion and the fourth portion, and wherein a second number of oxygen ions from the oxygen source are present in the first, second, third, and fourth portions of the tunnel barrier; and
a second electrode, wherein the fourth portion is between the third portion and the second electrode.
9. The memory cell of claim 8 , wherein the first portion has an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the second, third and fourth portions.
10. The memory cell of claim 8 , wherein the third portion has an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the second and fourth portions.
11. The memory cell of claim 8 , wherein the second portion has an activation energy for oxygen ion diffusion that is higher than an activation energy for oxygen ion diffusion of the fourth portion.
12. The memory cell of claim 8 , wherein the first portion, the second portion, the third portion, and the fourth portion each are approximately 25% of the tunnel barrier.
13. The memory cell of claim 8 , wherein the first portion is adjacent to the oxygen source and the fourth portion is adjacent to the second electrode.
14. A memory cell, comprising:
a first electrode;
an oxygen source, wherein the oxygen source includes a first number of oxygen ions;
a tunnel barrier, wherein the tunnel barrier includes alternating portions of a first material and a second material that is different from the second material, wherein the alternating portions include at least two portions of the first material and at least two portions of the second material, wherein one portion of the at least two portions of the second material is between the at least two portions of the first material, and wherein a second number of oxygen ions from the oxygen source are present in the alternating portions of the tunnel barrier; and
a second electrode, wherein the alternating portions of the first material and the second material are between the oxygen source and the second electrode.
15. The memory cell of claim 14 , wherein the first material is aluminum oxide and the second material is hafnium oxide.
16. The memory cell of claim 14 , wherein the first material is adjacent to the oxygen source.
17. The memory cell of claim 14 , wherein the second material is adjacent to the second electrode.
18. The memory cell of claim 14 , wherein the first material is silicon dioxide (SiO 2 ) and the second material is zirconium oxide.
19. The memory cell of claim 14 , wherein the oxygen source is perovskite metal oxide (PCMO).