A method of making provides a smooth surface of a pinned or free layer interfacing
a barrier layer in a tunnel junction sensor wherein the smooth surface is an oxidized
monolayer of the pinned or free layer. After sputter depositing the pinned or free
layer the layer is subjected to an oxygen (O2) atmosphere which is extremely
low for a very short duration. In a preferred embodiment of the invention a partial
thickness of the barrier layer is provided with a smooth surface by the same process
after which a remainder thickness of the barrier layer is deposited and the barrier
layer is exposed to oxygen (O2) to form an oxide of the deposited metal.
