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WRITE GAP PROTECTION WITH A TANTALUM SACRIFICIAL LAYER

IP.com Disclosure Number: IPCOM000014366D
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Abstract

In the sequencing of fabricating a write head, a write gap is first deposited on a first pole piece (P1) followed by the fabrication of insulation and coil layers. The gap material, Al2O3, during these fabrication steps is eroded by developer attack and physical sputtering. Since a photo rework process further reduces the gap thickness and the rework required is unpredictable, it is difficult to compensate for the gap thickness loss by depositing a thicker gap on P1. This gap loss problem becomes more severe for write heads with dual coils and a thinner gap. Disclosed is a method of preserving write gap thickness during processing. In the disclosed method, after a write gap is deposited on P1, a tantalum layer is deposited over the gap layer. The processing then proceeds with the fabrication of insulation and coil layers. Since the Al2O3 gap is now covered by the tantalum layer, it will not be eroded by developer attack or sputtering. Furthermore, since tantalum is attacked only by physical sputtering (not by developer), it is now feasible to windage the thickness loss. Before the process module of making the second pole piece (P2), a tantalum RIE process is applied to remove the tantalum layer selectively from the Al2O3 gap. The Al2O3 gap loss during this RIE process can be eliminated by using an optimized Ta RIE process, preferably in a high density plasma. The insulation loss can also be minimized by using a CHF3-containing plasma. The RIE process is anisotropic without lateral etching so that the tantalum layer under the insulation is left intact and the insulation integrity is maintained. 1

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WRITE GAP PROTECTION WITH A TANTALUM SACRIFICIAL LAYER

      In the sequencing of fabricating a write head, a write gap is first deposited on a first pole piece (P1) followed by the fabrication of insulation and coil layers. The gap material, Al2O3, during these fabrication steps is eroded by developer attack and physical sputtering. Since a photo rework process further reduces the gap thickness and the rework required is unpredictable, it is difficult to compensate for the gap thickness loss by depositing a thicker gap on P1. This gap loss problem becomes more severe for write heads with dual coils and a thinner gap.

      Disclosed is a method of preserving write gap thickness during processing. In the disclosed method, after a write gap is deposited on P1, a tantalum layer is deposited over the gap layer. The processing then proceeds with the fabrication of insulation and coil layers. Since the Al2O3 gap is now covered by the tantalum layer, it will not be eroded by developer attack or sputtering. Furthermore, since tantalum is attacked only by physical sputtering (not by developer), it is now feasible to windage the thickness loss. Before the process module of making the second pole piece (P2), a tantalum RIE process is applied to remove the tantalum layer selectively from the Al2O3 gap. The Al2O3 gap loss during this RIE process can be eliminated by using an optimized Ta RIE process, preferably in a high density plasma. The insulation loss can also be minimized by using...