Process of manufacturing a seed/AFM combination for a CPP GMR device

• US 7,331,100 B2
• Filed: 07/07/2004
• Issued: 02/19/2008
• Est. Priority Date: 07/07/2004
• Status: Expired due to Fees

• Current Assignee: Headway Technologies Incorporated
• Original Assignee: Headway Technologies Incorporated
• Inventors: Chen, Yu-Hsia, Liu, Yue, Tong, Ru-Ying, Li, Min, Horng, Cheng T., Han, Cherng Chyi
• Primary Examiner(s): TUGBANG, ANTHONY D
• Application Number:
  US10/886,288
• Publication Number:
  US 20060007605A1
• Time in Patent Office: 1,322 Days
• Field of Search: 296/031.4, 296/031.3, 296/031.5, 296/031.8, 296/030.7, 216/22, 427/404, 427/131, 427/132, 428/812, 428/811.2, 428/811.3, 360/122, 360/125, 360/126, 360/313, 360/319, 360/324, 360/324.11, 360/324.12, 360/326
• US Class Current: 29/603.14
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3932 Magnetic biasing films
• CPC Class Codes: Y10T 29/49043 Depositing magnetic layer or coating
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers
• CPC Class Codes: Y10T 428/115 Magnetic layer composition

Abstract

An improved seed/AFM structure is formed by first depositing a layer of tantalum on the lower shield. A NiCr layer is then deposited on the Ta followed by a layer of IrMn. The latter functions effectively as an AFM for thicknesses in the 40-80 Angstrom range, enabling a reduced shield-to-shield spacing.

Claims

1. A process to manufacture a CPP GMR read head, comprising:

providing a lower shield layer having an upper surface and then cleaning said upper surface through plasma etching;

depositing a layer of tantalum, between about 3 and 10 Angstroms thick, on said cleaned surface;

depositing a layer of NiCr, between about 30 and 60 Angstroms thick, on said layer of tantalum whereby said tantalum and NiCr layers together form a seed layer;

depositing a layer of IrMn on said seed layer;

on said IrMn layer, depositing an AP2 layer;

depositing a layer of AFM coupling material on said AP2 layer;

depositing an AP1 layer on said layer of AFM coupling material;

depositing a non-magnetic spacer layer on said AP1 layer;

depositing a free layer on said non-magnetic spacer layer; and

forming a capping layer on said free layer.

2. The process described in claim 1 wherein said IrMn layer is deposited to a thickness between 40 and 80 Angstroms.

3. The process described in claim 1 wherein said CPP GMR read head has a GMR ratio greater than 5%.

4. The process described in claim 1 wherein said free layer is selected from the group consisting of CoFe, CoFe/NiFe, and [CoFeCu]₂/CoFe.

5. The process described in claim 1 wherein said free layer has a thickness between about 15 and 60 Angstroms.

6. The process described in claim 1 wherein said capping layer is selected from the group consisting of Cu/Ta, GuRu, and Cu/Ru/Ta/Ru.

7. The process described in claim 1 wherein the step of cleaning said upper surface through plasma etching further comprises using argon flowing at a rate of about 30 SCCM at a power level of about 50 W for about 10 minutes.

8. A process to manufacture a CPP GMR read head, comprising:

providing a lower shield layer having an upper surface and then cleaning said upper surface through plasma etching;

depositing a layer of tantalum, between about 3 and 10 Angstroms thick, on said cleaned surface;

depositing a layer of NiCr, between about 30 and 60 Angstroms thick, on said layer of tantalum whereby said tantalum and NiCr layers together form a seed layer;

depositing a layer of IrMn on said seed layer;

on said IrMn layer, depositing an AP2 layer;

depositing a layer of AFM coupling material on said AP2 layer;

depositing an AP1 layer on said layer of AFM coupling material;

depositing a first copper layer, between about 1.5 and 6 Angstroms thick, on said AP1 layer;

depositing an AICu layer, between about 6 and 10 Angstroms thick, on said first copper layer;

then subjecting said AICu layer to a low power plasma etch, thereby removing about 1 to 3 Angstroms of said AICu layer;

then converting said AICu layer to a nano-oxide layer by means of plasma oxidation;

then depositing a second copper layer on said nano-oxide layer whereby said first and second copper layers, together with said nano-oxide layer, form a non-magnetic spacer layer on said AP1 layer;

then depositing a free layer on said non-magnetic spacer layer; and

forming a capping layer on said free layer.

9. The process described in claim 8 wherein said IrMn layer is deposited to a thickness between 40 and 80 Angstroms.

10. The process described in claim 8 wherein said CPP GMR read head has a GMR ratio greater than 5%.

11. The process described in claim 8 wherein said free layer is selected from the group consisting of CoFe, CoFe/NiFe, and (CoFeCu)₂/CoFe.

12. The process described in claim 8 wherein said free layer has a thickness between about 15 and 60 Angstroms.

13. The process described in claim 8 wherein said capping layer is selected from the group consisting of Cu/Ta, GuRu, and Cu/Ru/Ta/Ru.

14. The process described in claim 8 wherein the step of cleaning said upper surface through plasma etching further comprises using argon flowing at a rate of about 30 SCCM at a power level of about 50 W for about 10 minutes.

15. The process described in claim 8 wherein the step of subjecting said AICu layer to said low power plasma etch further comprises using argon flowing at a rate of about 50 SCCM at a power level of about 17 to 20 W for about 20 to 60 seconds.

16. The process described in claim 8 wherein the step of converting said AICu layer to said nano-oxide layer by means of plasma oxidation further comprises using argon flowing at a rate of about 50 SCCM, together with oxygen flowing at a rate of 15 SCCM, at a power level of about 20 to 30 W for about 15 to 45 seconds.

17. The process described in claim 8 wherein said CPP GMR read head has a R.A product that is greater than 0.4 ohms.m².