Method and system for providing a magnetoresistive structure using undercut free mask
View Patent ↗A method and system provide a magnetoresistive structure from a magnetoresistive stack that includes a plurality of layers. The method and system include providing a mask that exposes a portion of the magnetoresistive stack. The mask has at least one side, a top, and a base at least as wide as the top. The method and system also include removing the portion of the magnetoresistive stack to define the magnetoresistive structure. The method and system further include providing an insulating layer. A portion of the insulating layer resides on the at least one side of the mask. The method and system further include removing the portion of the insulating layer on the at least one side of the mask and removing the mask.
1. A method for defining a magnetoresistive structure from a magnetoresistive stack including a plurality of layers, the method comprising:
providing a mask, the mask exposing a portion of the magnetoresistive stack, the mask having at least one side, a top, and a base at least as wide as the top;
removing the portion of the magnetoresistive stack to define the magnetoresistive structure;
providing an insulating layer, a portion of the insulating layer residing on the at least one side of the mask;
providing a capping layer on the insulating layer;
removing the portion of the insulating layer on the at least one side of the mask; and
removing the mask, the step of removing the portion of the insulating layer further including removing a portion of the capping layer on the at least one side of the mask.
2. The method of claim 1 wherein the insulator includes alumina and the capping layer includes at least one of Ta and diamond-like carbon.
3. The method of claim 1 wherein the mask has a top surface, step of removing the portion of the insulating layer further includes:
performing an ion mill at an angle from normal to the top surface, the angle being at least sixty degrees.
4. The method of claim 3 wherein the angle is at least seventy degrees and not more than eighty degrees.
5. The method of claim 1 further comprising:
performing a touch planarization after the step of removing the mask.
6. The method of claim 5 wherein the touch planarization is a touch chemical mechanical planarization (CMP) and wherein the touch CMP is performed using at least one of a pressure of not more than two psi.
7. The method of claim 1 further comprising:
providing a bottom antireflective coating (BARC) layer under the mask.
8. The method of claim 7 further comprising:
removing the BARC layer after the step of removing mask.
9. The method of claim 7 wherein the BARC layer includes an organic BARC layer.
10. The method of claim 7 wherein the BARC includes an inorganic BARC layer.
11. The method of claim 10 wherein the BARC layer includes at least one of diamond-like carbon and silicon nitride.
12. The method of claim 1 wherein the step of removing the portion of the magnetoresistive stack further includes:
defining a track width of the magnetoresistive structure to be not more than forty nanometers.
13. The method of claim 1 wherein the mask is a single layer mask.
14. A method for defining a magnetoresistive structure from a magnetoresistive stack including a plurality of layers, the method comprising:
providing a bottom antireflective coating (BARC) layer;
providing a single layer mask having at least one side, a top, and a base at least as wide as the top, the single layer mask exposing a portion of the magnetoresistive stack and a portion of the BARC layer;
removing the portion of the BARC layer, a covered portion of the BARC layer remaining;
removing the portion of the magnetoresistive stack to define the magnetoresistive structure;
providing an insulating layer, a portion of the insulating layer residing on the at least one side of the single layer mask and the at least one side of the covered portion of the BARC layer;
providing a capping layer on the insulating layer;
performing an ion mill at an angle from normal to the top surface, the angle being at least seventy degrees and not more than eighty degrees, the ion mill removing the portion of the insulating layer on the at least one side of the single layer mask and a portion of the capping layer on the at least one side of the insulating layer;
performing a lift off, the lift off removing the single layer mask;
removing a remaining portion of the covered portion of the BARC layer, a top of the magnetoresistive structure being exposed; and
performing a touch planarization.
15. The method of claim 14 wherein the step of removing the portion of the BARC layer further includes:
performing a reactive ion etch.
16. The method of claim 14 wherein the touch planarization is a touch chemical mechanical planarization (CMP) and wherein the touch CMP is performed using a pressure of not more than two psi.