Passivation of Oxides
Original Publication Date: 1988-Feb-01
Included in the Prior Art Database: 2005-Feb-14
By admixing traces of metal oxides (such as Fe, Ni, Cr) to Al2O3 or other oxides, it is possible to passivate such oxides against the attack of alkaline or acid etchants. In one application, the layer thickness of the gap of a magnetic head can be protected against alkaline developers used in a photoresist process. During the manufacture of magnetic heads, insulating layers of Al2O3 are produced by sputtering between magnetic layers forming the magnet yoke. For this purpose, a sputter target of highly pure Al2O3 is normally used. The attack of the alkaline developers and strippers, used in the photoresist (process) step, on the highly pure Al2O3 leads to fluctuations particularly in the thickness of the gap separating layer. A reproducible thickness of this layer is however of utmost importance.