In a method of fabricating a giant magnetoresistive (GMR) device a
plurality of magnetoresistive device layers is deposited on a first
silicon nitride layer formed on a silicon oxide layer. An etch stop is
formed on the magnetoresistive device layers, and a second layer of
silicon nitride is formed on the etch stop. The magnetoresistive device
layers are patterned to define a plurality of magnetic bits having
sidewalls. The second silicon nitride layer is patterned to define
electrical contact portions on the etch stop in each magnetic bit. The
sidewalls of the magnetic bits are covered with a photoresist layer. A
reactive ion etch (RIE) process is used to etch into the first silicon
nitride and silicon oxide layers to expose electrical contacts. The
photoresist layer and silicon nitride layers protect the magnetoresistive
layers from exposure to oxygen during the etching into the silicon oxide
layer.