Magnetoresistive stack/structure and method of manufacturing same
A method of manufacturing a magnetoresistive stack/structure comprising (a) etching through a second magnetic region to (i) provide sidewalls of the second magnetic region and (ii) expose a surface of a dielectric layer, (b) depositing a first encapsulation layer on the sidewalls of the second magnetic region and over a surface of the dielectric layer. (c) thereafter: (i) etching the first encapsulation layer which is disposed over the dielectric layer using a first etch process, and (ii) etching re-deposited material using a second etch process, wherein, after such etching, a portion of the first encapsulation layer remains on the sidewalls of the second magnetic region, (d) etching (i) through the dielectric layer to form a tunnel barrier and provide sidewalls thereof and (ii) etching the first magnetic region to provide sidewalls thereof, and (e) depositing a second encapsulation layer on the sidewalls of the tunnel barrier and first magnetic region.
1. A method of manufacturing a magnetoresistive structure including an intermediate layer disposed between a first magnetic region and a second magnetic region, the method comprising:
(a) etching through the second magnetic region to form exposed surfaces, wherein, after etching, at least a portion of the exposed surfaces includes re-deposited material;
(b) depositing a first encapsulation layer on the exposed surfaces;
(c) etching at least a portion of re-deposited material after step (b);
(d) depositing a second encapsulation layer; and
(e) after step (d), etching a portion of the first magnetic region.
2. The method of claim 1 , wherein depositing the second encapsulation layer includes depositing the second encapsulation layer after step (c).
3. The method of claim 1 , wherein the first encapsulation layer and the second encapsulation layer include one or more of a silicon oxide, a silicon nitride, or a tetraethylorthosilicate (TEOS).
4. The method of claim 3 , wherein the first encapsulation layer and the second encapsulation layer have different compositions.
5. The method of claim 1 , wherein the exposed surfaces include at least a portion of the intermediate layer.
6. The method of claim 1 , wherein the first encapsulation layer is deposited after the exposed surfaces are formed.
7. The method of claim 1 , wherein step (a) includes etching through a portion of the intermediate layer.
8. The method of claim 1 , wherein one or more of step (a) or step (c) includes using a physical etch process.
9. The method of claim 1 , wherein, after step (a), the second magnetic region has a width less than a width of the first magnetic region, or the second magnetic region has a diameter less than a diameter of the first magnetic region.
10. A method of manufacturing a magnetoresistive structure including an intermediate layer disposed between a first magnetic region and a second magnetic region, the method comprising:
(a) etching through the second magnetic region to form exposed surfaces, wherein, after etching, at least a portion of the exposed surfaces includes re-deposited material;
(b) depositing a first encapsulation layer on the exposed surfaces, after step (a);
(c) etching at least a portion of re-deposited material after step (b);
(d) etching the intermediate layer; and
(e) prior to etching the intermediate layer, depositing a second encapsulation layer.
11. The method of claim 10 , wherein one or more of step (a), step (b), or step (c), includes an ion beam etch.
12. The method of claim 11 , wherein on or more of step (a), step (b), or step (c), includes a physical etch.
13. The method of claim 10 , wherein the second encapsulation layer has a dimension greater than a corresponding dimension of the first encapsulation layer.
14. A method of manufacturing a magnetoresistive structure including an intermediate layer disposed between a first magnetic region and a second magnetic region, the method comprising:
(a) etching through the second magnetic region, wherein the etching is terminated at the intermediate layer and generates re-deposited material;
(b) depositing a first encapsulation layer;
(c) etching a portion of the re-deposited material;
(d) depositing a second encapsulation layer; and
(e) etching a portion of the intermediate layer, wherein depositing the second encapsulation layer includes depositing the second encapsulation layer prior to etching the intermediate layer.
15. The method of claim 14 , wherein, after step (a), the second magnetic region has a width less than a width of the first magnetic region, or the second magnetic region has a diameter less than a diameter of the first magnetic region.
16. The method of claim 14 , further comprising etching a portion of the first magnetic region.