Methods of making magnetic heads with improved contiguous junctions
View Patent ↗Methods of making a read head with improved contiguous junctions are described. After sensor layer materials are deposited over a substrate, a lift-off mask is formed over the sensor layer materials in a central region which is surrounded by end regions. Ion milling is performed with use of the lift-off mask such that the sensor layer materials in the end regions are removed and those in the central region remain to form a read sensor. A high-angle ion mill (e.g. between 45–80 degrees) is then performed to remove redeposited material from side walls of the lift-off mask. Next, a reactive ion etch (RIE) is used to reduce the thickness and the width of the lift-off mask and to remove capping layer materials from the top edges of the read sensor. With the reduced-size lift-off mask in place, hard bias and lead layers are deposited adjacent the read sensor as well as over the mask. The reduced-size lift-off mask allows the amount of hard bias to be increased in the contiguous junction region, and the edges of the leads to be deposited more closely over the top edges of the read sensor. Advantageously, the stability of the sensor is enhanced and the transfer curve is improved using a method which can be controlled independently from the initial mask structure and ion milling process. No critical alignments or multiple photoresist processes are necessary.
1. A method of making a magnetic head, comprising:
forming sensor layer materials over a substrate;
forming a lift-off mask over the sensor layer materials in a central region which is surrounded by end regions;
milling, with use of the lift-off mask, such that the sensor layer materials in the end regions are removed and the sensor layer materials in the central region remain to thereby form a read sensor;
after the act of milling, etching the lift-off mask to reduce a size of the lift-off mask; and
with the reduced-sized lift-off mask in place, depositing hard bias and lead layers in the end regions adjacent the read sensor.
2. The method of claim 1 , wherein the act of etching the lift-off mask comprises reactive ion etching (RIE).
3. The method of claim 1 , further comprising:
wherein the act of milling comprises a low-angle ion milling; and
after the milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask.
4. The method of claim 1 , further comprising:
wherein the act of milling comprises a low-angle ion milling;
after the milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask; and
wherein the act of etching comprises reactive ion etching (RIE).
5. The method of claim 1 , further comprising:
wherein the act of milling comprises a low-angle ion milling;
after the milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask and to define a target track width (TW) of the magnetic head; and
wherein the act of etching comprises a low-angle ion milling to reduce a thickness of the lift-off mask.
6. The method of claim 1 , wherein the act of etching comprises etching to reduce the thickness and the width of a top photoresist layer of the lift-off mask.
7. The method of claim 1 , wherein the act of etching comprises removing capping layer materials from top edges of the read sensor and the act of depositing lead layers comprises depositing lead layers over the top edges of the read sensor.
8. The method of claim 1 , wherein the lift-off mask includes a release layer and the method further comprises the act of:
dissolving the release layer to remove the reduced size lift-off mask from the read sensor.
9. A method of making a magnetic head, comprising:
forming sensor layer materials over a substrate;
forming a liftoff mask over the sensor layer materials in a central region which is surrounded by end regions;
ion milling, with use of the lift-off mask, such that the sensor layer materials in the end regions are removed and the sensor layer materials in the central region remain to thereby form a read sensor;
after the act of milling, reactive ion etching (RIE) the lift-off mask to reduce a size of the lift-off mask;
depositing hard bias and lead layers adjacent the read sensor with the use of the reduced-sized lift-off mask; and
removing the reduced-sized lift-off mask from the read sensor.
10. The method of claim 9 , further comprising the act of:
after the ion milling and prior to the RIE, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask.
11. The method of claim 9 , wherein the act of RIE comprises reducing the thickness and the width of the lift-off mask.
12. The method of claim 9 , further comprising:
wherein the act of ion milling comprises low-angle ion milling; and
after the ion milling and prior to the RIE, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask.
13. The method of claim 9 , wherein the act of RIE comprises removing capping layer materials from top edges of the read sensor and the act of depositing lead layers comprises depositing lead layers over the top edges of the read sensor.
14. The method of claim 9 , wherein the act of removing the reduced-sized lift-off mask comprises dissolving a release layer of the lift-off mask to remove the reduced size lift-off mask from the read sensor.
15. A method of making a read head so that the read head has improved contiguous junctions, the method comprising:
forming sensor layer materials over a gap layer;
forming a lift-off mask over the sensor layer materials in a central region which is surrounded by end regions;
ion milling, with use of the lift-off mask, such that the sensor layer materials in the end regions are removed and the sensor layer materials in the central region remain to thereby form a read sensor;
after the act of milling, etching the lift-off mask to reduce the size thereof and to remove capping layer materials from top edges of the read sensor;
with the reduced-sized lift-off mask in place, depositing hard bias and lead layers in the end regions adjacent the read sensor such that edges of the lead layers are formed over the top edges of the read sensor; and
removing the reduced-sized lift-off mask from the read sensor.
16. The method of claim 15 , wherein the act of etching comprises reactive ion etching (RIE).
17. The method of claim 15 , further comprising:
wherein the act of ion milling comprises a low-angle ion milling; and
after the ion milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask.
18. The method of claim 15 , further comprising:
wherein the act of ion milling comprises a low-angle ion milling;
after the ion milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask; and
wherein the act of etching comprises reactive ion etching (RIE).
19. The method of claim 15 , further comprising:
wherein the act of ion milling comprises a low-angle ion milling;
after the ion milling and prior to the etching, exposing the lift-off mask to a high-angle ion mill to remove redeposited material on side walls of the lift-off mask and to define a target track width (TW) of the magnetic head; and
wherein the act of etching comprises a low-angle ion milling to reduce a thickness of the lift-off mask.
20. The method of claim 15 , wherein the act of reducing the thickness and the width of the lift-off mask comprises reducing them by at least 10 percent.