Application of laser microetching in formation of air-bearing surface for magnetic head sliders

Laser-induced etching of polycrystalline Al₂O₃TiC material by a tightly-focused CW Ar ion laser has been investigated in a KOH solution with different concentrations. It is found that the KOH concentration can strongly affect the etching quality where low KOH concentration can result in rough and irregular patterns. The etching effect is also related to laser power and scanning speed. Laser-induced etching of polycrystalline Al₂O₃TiC in a KOH solution is found to be a photothermal reaction in which a threshold laser power exists. With an appropriate set of etching parameters, well defined grooves can be obtained with clean side walls and with an etching rate up to several hundred micrometers per second. It is also found that the grains in the polycrystalline Al₂O₃TiC material play an important role in the etching dynamics and etching quality. This etching process is believed to be applicable to the formation of a slider surface of magnetic heads in the future.