THIN FILM MEDIUM HAVING CARBON OVERCOAT, FORMING METHOD OF CARBON OVERCOAT, AND ITS PRODUCTION

摘要

PURPOSE: To obtain a thin film medium having a thin carbon overcoat and high wear resistance. CONSTITUTION: This thin film magnetic disk has a carbon overcoat 14. The surface density of nitrogen atoms on the carbon overcoat 14 measured by Rutherford's back scattering method is 3 to 8×10<16> atoms/cm<2> . The corrosion rate of the overcoat 14 measured by bringing an Al2 O3 particle tape to the medium is many times as small as the corrosion rate of a carbon overcoat of same thickness formed by sputtering in pure Ar atmosphere. The overcoat 14 is preferably formed to 8.0 to 15.0nm thickness.