Method for forming magnetic tunnel junction cell
A method for forming a magnetic tunnel junction cell includes forming a pinning layer, a pinned layer, a dielectric layer and a free layer over a first electrode, forming a second electrode on the free layer, etching the free layer and the dielectric layer using the second electrode as an etch barrier to form a first pattern, forming a prevention layer on a sidewall of the first pattern, and etching the pinned layer and the pinning layer using the second electrode and the prevention layer as an etch barrier to form a second pattern.
1. A method for forming a magnetic tunnel junction cell, the method comprising:
forming a pinning layer, a pinned layer, a dielectric layer and a free layer over a first electrode;
forming a second electrode on the free layer;
etching the free layer, the dielectric layer and the pinned layer using the second electrode as an etch barrier to form a first pattern;
forming a prevention layer on a sidewall of the first pattern;
etching the pinning layer using the second electrode and the prevention layer as an etch barrier to form a second pattern; and
performing a post treatment after etching the pinning layer and before etching the first electrode,
wherein the prevention layer is a polymer layer, wherein the polymer layer is removed after etching the pinning layer to form the second pattern, and before performing the post treatment.
2. The method of claim 1 , wherein the polymer layer is formed using a gas selected from the group consisting of a carbon fluoride gas, a hydrocarbon gas, a methyl fluoride gas, and a combination thereof.
3. The method of claim 1 , wherein etching the free layer, the dielectric layer and the pinned layer and etching the pinning layer are performed using a gas selected from the group consisting of CH 3 OH gas, CO gas, Cl 2 gas, HBr gas and a combination thereof.
4. The method of claim 1 , wherein etching the free layer, the dielectric layer and the pinned layer and etching the pinning layer are performed at a temperature of approximately 100° C. to approximately 500° C.
5. The method of claim 1 , further comprising performing another post treatment after etching the free layer, the dielectric layer and the pinned layer and before forming the prevention layer.
6. The method of claim 5 , wherein the post treatment comprises:
performing a H 2 O plasma treatment; and
performing a hot deionized water treatment.
7. The method of claim 5 , wherein the post treatment is performed at a temperature of approximately 100° C. to approximately 500° C.
8. A method for forming a magnetic tunnel junction cell, the method comprising:
forming a pinning layer, a pinned layer, a dielectric layer and a free layer over a first electrode;
forming a second electrode on the free layer;
etching the free layer, the dielectric layer and the pinned layer using the second electrode as an etch barrier to form a first pattern;
performing a first post treatment after etching the free layer, the dielectric layer and the pinned layer;
forming a prevention layer on a sidewall of the first pattern after performing the first post treatment;
etching the pinning layer using the second electrode and the prevention layer as an etch barrier to form a second pattern; and
performing a second post treatment after etching the pinning layer and before etching the first electrode,
wherein the prevention layer is a polymer layer, wherein the polymer layer is removed after etching the pinning layer to form the second pattern, and before performing the post treatment.
9. The method of claim 8 , wherein the first post treatment comprises performing a H2O plasma treatment followed by a hot deionized water treatment at a temperature of approximately 100° C. to approximately 500° C.
10. The method of claim 8 , wherein the second post treatment comprises performing a H2O plasma treatment followed by a hot deionized water treatment at a temperature of approximately 100° C. to approximately 500° C.