Patent ID: 11894222
Assignee: TOKYO ELECTRON LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  C | IPC C  H

Claim 6:
7. A method of determining a timing for replacing a target in a film forming apparatus, wherein
the target is made of a ferromagnetic material,
the film forming apparatus includes
a substrate holder configured to hold a substrate for forming a film thereon by a magnetron sputtering,
a target holder configured to hold the target to face the substrate holder and extend in a depth direction of the film forming apparatus,
a magnet provided on a surface of the target holder opposite to the substrate holder, and configured to leak a magnetic field to a front surface of the target held by the target holder that is a surface close to the substrate holder,
a driver configured to swing the magnet along a back surface of the target holder in the depth direction of the film forming apparatus, and
a Gauss meter including a hole probe with a hole sensor provided therein and configured to measure a strength of the magnetic field, and

the method comprising:
measuring the strength of the magnetic field; and
determining a timing for replacing the target based on the measured strength of the magnetic field,
wherein a tip of the hole probe is provided at a position substantially coincident with a center of the target held by the target holder in the depth direction of the film forming apparatus.