High-rate and smooth surface etching of Al2O3-TiC employing inductively coupled plasma (ICP)

High-rate and smooth surface etching of Al2O3-TiC, which is widely used as a slider material for magnetic recording heads, has been developed employing inductively coupled plasma (ICP). The etching rate of 200 nm/min was obtained with Cl-2/BCl3 mixture. However the etched morphology exhibited roughness around 40 nm Ra (arithmetic average deviation from center line) because of different etching rates for Al2O3 and TiC grains in the substrate. The addition of Ar to the Cl-2/BCl3 improved both the etching rate and roughness of the etched surface considerably. As a result the high etching rate of more than 350 nm/min, which is more than ten times that of conventional Ar+ on etching, and relatively smooth surface roughness around 20 nm Ra were achieved with Ar/Cl-2/BCl3 mixture using 1.2 kW RF power and -500 V V-dc.