Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55-85°. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15-60° and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g., CH2FCF3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic bead and magnetic disc.

Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55-85.degree.. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15-60.degree. and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g., CH.sub.2 FCF.sub.3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF.sub.6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic head and magnetic disc.

Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55.degree.-85.degree.. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15.degree.-60.degree. and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g. CH.sub.2 FCF.sub.3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF.sub.6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic head and magnetic disc.

Abstract: A thickness/depth measuring apparatus and method for measuring the thickness of a film forming a lattice-shaped mask and the depth of a groove formed on a workpiece during processing of the workpiece. The thickness/depth measuring apparatus and method provide for irradiating the workpiece with a coherent light beam, controlling the direction for linear polarization of the coherent light beam irradiated onto the workpiece, adjusting the incident angle of the coherent light beam irradiated onto the workpiece in a predetermined angular range, receiving and detecting reflected light reflected by the workpiece at different irradiated incident angles and including higher-order diffracted light; and calculating the thickness of the film and the depth of the groove in accordance with the intensity of the diffracted light detected.