Abstract
Recent trend of high recording density and consequently low magnetic spacing in HDD technology has necessitated strict control of the mechanical flying height (FH) of the sliders above magnetic disk. The FH is typically measured on the glass disk with interferometric methods to determine the FH from interference light intensity. The intensity is often affected by the variation of the refractive index (n, k) of the air bearing surface (ABS). This paper describes efforts to (A) predict FH variation due to n, k variation from the principle of the FH testers commercially available, (B) Verify the relation of the FH-n, k relation from (A) by affecting the n, k value set-up on the FH testers and measuring the FH, and lastly, (C) apply the relation to correct FH values and demonstrate corrected value show better FH variation.
