EVALUATIONS OF DIAMOND-LIKE-CARBON FILM OPTICAL-CONSTANTS AND THEIR EFFECTS ON FLYING HEIGHT DETERMINATION

The accuracy in flying height determination of a film coated magnetic slider relies on the availability of accurate optical property values of each film. In view of this, the index of refraction and coefficient of extinction of carbon and underlayer films, as used on a magnetic s lider, was evaluated in this study. Various thicknesses of carbon and underlayer films were coated on Al2O3-TiC substrates, and their optica l properties were determined by using a variable angle spectroscopic e llipsometer at multiple angles of incidence and two optical models via reasonable range and least square methods. Then the effects of the ca rbon and underlayer films on flying height measurement were assessed. It was found that the optical properties of the underlayer film are st rongly thickness and wavelength dependent. Therefore, the flying heigh t measurement errors caused by incorrect treatment of the films are fu nctions of film thickness and light wavelength.