Method for forming a read transducer by ion milling and chemical mechanical polishing to eliminate nonuniformity near the MR sensor

• US 7,008,550 B2
• Filed: 09/25/2003
• Issued: 03/07/2006
• Est. Priority Date: 09/25/2003
• Status: Expired due to Fees

• Current Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Li, Jui-Lung, Lo, Jyh-Shuey
• Primary Examiner(s): Hassanzadeh, Parviz
• Assistant Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US10/671,085
• Publication Number:
  US 20050067372A1
• Time in Patent Office: 894 Days
• Field of Search: 216/22, 438/3
• US Class Current: 216/22
• CPC Class Codes: G11B 5/3106 where the integrated or assembled structure comprises means for conditioning against physical detrimental influence, e.g. wear, contamination G11B5/3133 takes precedence
• CPC Class Codes: G11B 5/3116 Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks G11B5/3113, G11B5/245 take precedence
• CPC Class Codes: G11B 5/313 Disposition of layers
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
• CPC Class Codes: G11B 5/39 using magneto-resistive devices or effects
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3932 Magnetic biasing films
• CPC Class Codes: G11B 5/59683 for magnetoresistive heads
• CPC Class Codes: Y10T 29/49021 Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
• CPC Class Codes: Y10T 29/49032 Fabricating head structure or component thereof

Abstract

A method for forming a read transducer by ion milling and chemical mechanical polishing to eliminate nonuniformity near the MR sensor is disclosed. The resist mask is eliminated in the read transducer formation process so that the thickness of the layers near the read transducer has a uniform thickness.

Claims

1. A method for forming a read transducer, comprising:

forming, over a sensor, a first hard layer having a width for defining a width of the sensor;

forming, on a first and second side of the sensor and hard layer, a hard bias layer having a height substantially equal to a height of the sensor;

forming a lead layer over the hard layer and the hard bias layer;

forming a second hard layer over the lead layer;

forming, over the second hard layer, a top mask layer having an opening substantially equal to the width of the sensor;

removing a portion of the second hard layer and a portion of the lead layer accessible through the opening in the top mask layer;

removing the top mask layer; and

shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form.

2. The method of claim 1 wherein the forming, over a sensor, a first hard layer having a width for defining a width of the sensor further comprises forming a sensor layer, forming a first hard layer over the sensor layer, forming a photoresist over the hard layer where the sensor is to be formed and removing portions of the first hard layer and the sensor layer that are not obscured by the photoresist.

3. The method of claim 1 wherein the removing portions of the first hard layer and the sensor layer that are not obscured by the photoresist further comprises ion milling portions of the first hard layer and the sensor layer that are not obscured by the photoresist.

4. The method of claim 2, wherein the forming, on a first and second side of the sensor and hard layer, a hard bias layer having a height substantially equal to a height of the sensor further comprises depositing a hard bias layer over and around the first hard layer having a width for defining the sensor, ion milling a portion of the hard bias layer until the hard bias layer comprises a first and second side portion opposite the sensor and first hard layer and a third portion over the first hard layer, depositing a bottom mask layer over the ion milled portion of the hard bias layer and the first hard layer, chemical mechanical polishing the bottom mask layer and the portion of the hard bias layer over the first hard layer until the first hard layer is encountered and wet etching the bottom mask layer and hard bias layer until the hard bias layer has a desired height.

5. The method of claim 4, wherein the depositing, over the second hard layer, a top mask layer having an opening substantially equal to the width of the sensor further comprises forming a top mask layer over the second hard layer and CMP polishing the top mask layer down to the second hard layer.

6. The method of claim 5, wherein the removing a portion of the second hard layer and a portion of the lead layer accessible through the opening in the top mask layer further comprises removing a portion of the second hard layer between the opening in the top mask layer using reactive ion etching (RIE) and removing a portion of the lead layer between remaining portions of the second hard layer by ion milling.

7. The method of claim 6, wherein the removing the top mask layer further comprise wet etching the top mask layer to remove the top mask layer.

8. The method of claim 7, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises CMP polishing the first hard layer and remaining portions of the lead layer and the second hard layer to remove portions of the remaining portions of the lead layer and the second hard layer away from the sensor to provide the remaining portions of the lead layer a surface sloping toward the first hard layer.

9. The method of claim 8, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises removing the first hard layer and the remaining portions of the second hard layer using reactive ion etching.

10. The method of claim 1, wherein the forming, on a first and second side of the sensor and hard layer, a hard bias layer having a height substantially equal to a height of the sensor further comprises depositing a hard bias layer over and around the first hard layer, ion milling a portion of the hard bias layer until the hard bias layer comprises a first and second side portion opposite the sensor and fist hard layer and a third portion over the first hard layer, depositing a bottom mask layer over the ion milled portion of the hard bias layer and the first hard layer, chemical mechanical polishing the bottom mask layer and the portion of the hard bias layer over the first hard layer until the first hard layer is encountered and wet etching the bottom mask layer and hard bias layer until the hard bias layer has a desired height.

11. The method of claim 10, wherein the depositing the bottom mask layer further comprise forming a layer of Al₂O₃.

12. The method of claim 1, wherein the forming, over the second hard layer, a top mask layer having an opening substantially equal to the width of the sensor further comprises forming a top mask layer over the second hard layer and CMP polishing the top mask layer down to the second hard layer.

13. The method of claim 1, wherein the removing a portion of the second hard layer and a portion of the lead layer accessible through the opening in the top mask layer further comprises removing a portion of the second hard layer between the opening in the top mask layer using reactive ion etching (RIE) and removing a portion of the lead layer between remaining portions of the second hard layer by ion milling.

14. The method of claim 1, wherein the removing the top mask layer further comprise wet etching the mask layer to remove the top mask layer.

15. The method of claim 1, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises CMP polishing the first hard layer and remaining portions of the lead layer and the second hard layer to remove portions of the remaining portions of the lead layer and the second hard layer away from the sensor to provide the remaining portions of the lead layer a surface sloping toward the first hard layer.

16. The method of claim 13, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises removing the first hard layer and the remaining portions of the second hard layer using reactive ion etching.

17. The method of claim 1, wherein the forming the hard bias layer further comprise forming a Chromium/hard bias layer.

18. The method of claim 1, wherein the forming the first hard layer further comprise forming a diamond-like carbon layer.

19. The method of claim 1, wherein the forming the second hard layer further comprise forming a diamond-like carbon layer.

20. The method of claim 1, wherein the forming the top mask layer further comprise forming a layer of Al₂O₃.

21. A method for forming a read transducer, comprising:

forming a sensor layer over a first gap layer;

forming, over the sensor layer, a first hard layer;

forming over the first hard layer a photoresist having a width equal to a desired width of a sensor;

removing portions of the first hard layer and the sensor layer not blocked by the photoresist to form a sensor;

removing the photoresist;

forming a hard bias layer on a first and second side of remaining portions of the first hard layer and sensor layer; and

processing a second hard layer, a lead layer and a masking layer formed over the hard bias layer and the remaining portions of the first hard layer and sensor layer using CMP polishing, ion etching and ion milling to prevent nonuniformity of layer thickness near the sensor.

22. The method of claim 21, wherein the forming a hard bias layer on a first and second side of remaining portions of the first hard layer and sensor layer further comprises depositing a hard bias layer over and around the first hard layer, ion milling a portion of the hard bias layer until the hard bias layer comprises a first and second side portion opposite the remaining portions of the first hard layer and sensor layer and a third portion over the first hard layer, depositing a bottom mask layer over the ion milled portion of the hard bias layer and the first hard layer, chemical mechanical polishing the bottom mask layer and the portion of the hard bias layer over the first hard layer until the first hard layer is encountered and wet etching the bottom mask layer and hard bias layer until the hard bias layer has a desired height.

23. The method of claim 22, wherein the depositing the bottom mask layer further comprise forming a layer of Al₂O₃.

24. The method of claim 21, wherein the processing a second hard layer, a lead layer and a masking layer formed over the hard bias layer and the remaining portions of the first hard layer and sensor layer further comprises forming, over the second hard layer, a top mask layer having an opening substantially equal to the width of the sensor by forming a top mask layer over the second hard layer and CMP polishing the top mask layer down to the second hard layer.

25. The method of claim 24, wherein the processing a second hard layer, a lead layer and a masking layer formed over the hard bias layer and the remaining portions of the first hard layer and sensor layer further comprises removing a portion of the second hard layer and a portion of the lead layer accessible through the opening in the top mask layer.

26. The method of claim 25, wherein the removing a portion of the second hard layer and a portion of the lead layer accessible through the opening in the top mask layer further comprises removing a portion of the second hard layer between the opening in the top mask layer using reactive ion etching (RIE) and removing a portion of the lead layer between remaining portions of the second hard layer by ion milling.

27. The method of claim 25, wherein the processing a second hard layer, a lead layer and a masking layer formed over the hard bias layer and the remaining portions of the first hard layer and sensor layer further comprises removing the top mask layer further comprise wet etching the mask layer to remove the top mask layer.

28. The method of claim 21, wherein the processing a second hard layer, a lead layer and a masking layer formed over the hard bias layer and the remaining portions of the first hard layer and sensor layer further comprises shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form.

29. The method of claim 28, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises CMP polishing the first hard layer and remaining portions of the lead layer and the second hard layer to remove portions of the remaining portions of the lead layer and the second hard layer away from the sensor to provide the remaining portions of the lead layer a surface sloping toward the first hard layer.

30. The method of claim 29, wherein the shaping a remaining portion of the second hard layer and a remaining portion of the lead layer to a desired form further comprises removing the first hard layer and the remaining portions of the second hard layer using reactive ion etching.

31. The method of claim 21, wherein the forming the first and second hard layers further comprise forming a diamond-like carbon layer.