A magneto-resistive device is improved in characteristics by removing a
surface oxide film to reduce the resistance and reducing an ion beam
damage. The magneto-resistive device has a magneto-resistive layer which
comprises a tunnel barrier layer, an underlying pinned layer, and an
overlying free layer. A non-magnetic layer is formed on the free layer
for protection. A composite-layer film comprised of an insulating layer
and a damage reducing layer is formed in contact with an effective region
which is effectively involved in detection of magnetism in the
magneto-resistive layer without overlapping with the effective region.
The damage reducing layer is made of a material which includes at least
one element, the atomic weight of which is larger than that of silicon.
The insulating layer and damage reducing layer do not constitute a
magnetic domain control layer for applying a biasing magnetic field to
the free layer.