LASER-INDUCED ETCHING OF POLYCRYSTALLINE AL2O3TIC IN KOH AQUEOUS-SOLUTION

Laser-induced etching of polycrystalline Al-2-O3TiC material by a tigh tly-focused cw Ar ion laser has been investigated in a KOH solution wi th different concentrations. It is found that the KOH concentration ca n strongly affect the etching quality where low KOH concentration call result in rough and irregular patterns. Laser-induced etching of poly crystalline Al2O3TiC in a KOH solution is found to be a photothermal r eaction in which a threshold laser power exists. With an appropriate s et of etching parameters, well-defined grooves can be obtained with cl ean side walls and with an etching rate up to several hundred micromet ers per second. The etching behavior is also found to depend on laser scanning direction. It is also found that the grains in the polycrysta lline Al2O3TiC material play an important role in the etching dynamics and etching quality. This etching process is believed to be applicabl e to the formation of a slider surface of magnetic heads in the future .