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NEW SPACER FOR GMR SENSOR

IP.com Disclosure Number: IPCOM000013077D
Original Publication Date: 2000-Apr-01
Included in the Prior Art Database: 2003-Jun-12
Document File: 1 page(s) / 25K

Publishing Venue

IBM

Abstract

Described is the use of a composite spacer for a GMR head. Copper is the most common non-magnetic spacer material between the free and the pinned layers of a GMR sensor. However, copper is known to have poor corrosion resistance, especially when exposed at the air bearing surface of a data storage sensor. Moreover, after annealing these sensors at high temperature, ferromagnetic coupling between the free and the pinned layer begins to increase, likely due to interdiffusion of these layers through porous copper material. The corrosion resistance can be enhanced and interdiffusion between the free and the pinned layers can be minimized by the use of a composite spacer. Examples are: Cu/Pt/Cu, Cu/Au/Cu. The copper is still present at the interfaces to the free and the pinned layers to achieve high magnetoresistance. The insertion of the other metal, such as Pt or Au, reduces pin hole density in the spacer and therefore minimizes the interdiffusion between the ferromagnetic metals. In-addition, Pt and Au possess higher corrosion resistance than Cu. 1

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NEW SPACER FOR GMR SENSOR

   Described is the use of a composite spacer for a GMR head. Copper is the most
common non-magnetic spacer material between the free and the pinned layers of a
GMR sensor. However, copper is known to have poor corrosion resistance,
especially when exposed at the air bearing surface of a data storage sensor.
Moreover, after annealing these sensors at high temperature, ferromagnetic
coupling between the free and the pinned layer begins to increase, likely due to
interdiffusion of these layers through porous copper material. The corrosion
resistance can be enhanced and interdiffusion between the free and the pinned
layers can be minimized by the use of a composite spacer. Examples are: Cu/Pt/Cu,
Cu/Au/Cu. The copper is still present at the interfaces to the free and the
pinned layers to achieve high magnetoresistance. The insertion of the other
metal, such as Pt or Au, reduces pin hole density in the spacer and therefore
minimizes the interdiffusion between the ferromagnetic metals. In-addition, Pt
and Au possess higher corrosion resistance than Cu.

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