A DAMAGE QUANTIFICATION METHOD FOR AIR-BEARING-SURFACE OVERCOATS ON MAGNETIC HEAD SLIDERS

A damage quantification method for air-bearing-surface (ABS) overcoats which consist of a Si underlayer and a carbon toplayer was developed. This method is applicable to head sliders composed of Al2O3-TiC. In t his method, a 70% HNO3 treatment is initially applied, to distinguish the ABS's exposed Al2O3-TiC area. A 3.5% HF treatment followed by a se cond 70% HNO3 treatment are then applied to reveal the region in which the carbon overcoat is worn out but the Si underlayer remains. In add ition to the amount of damage, the method also reveals the modes by wh ich ABS overcoats are damaged. Flaking at the carbon / silicon interfa ce was found to be the dominant damage mode when the ABS overcoat had relatively low adhesive strength.