Film thickness measuring method, polishing method, fabrication method of thin film magnetic head and substrate for forming the thin film magnetic head

摘要

The present invention relates to a film thickness measuring method measuring a film thickness of an element formation layer formed on a substrate and its object is to provide a film thickness measuring method which can measure a residual film thickness of a polishing object film in a polishing process at a high accuracy. In a fabrication method of a thin film magnetic head, alumina is coated over a dummy layer 54 and a bottom shielding layer 16 after forming the dummy layer 54 along with the bottom shielding layer 16 and a planarized layer 24 is formed by polishing the surface thereof using a CMP. Next, after forming a top shielding layer 32 over the bottom shielding layer 16, a planarized layer 38 is form by embedding alumina. A film thickness of an embedded 38 on the dummy layer 54 is measured by a non-contact optical film thickness measuring equipment and a film thickness of the top shielding layer 32 is measured based on the film thickness.