Substrate polishing system, substrate polishing method and substrate polishing apparatus

A substrate polishing method for sequentially polishing layers to be polished using a first substrate polishing apparatus and a second substrate polishing apparatus, each of which comprises a film thickness sensor for measuring a film thickness of the layers to be polished of a substrate and polishing the layers to be polished by pressing the substrate against a polishing pad,

• wherein the first substrate polishing apparatus outputs a difference, as a first offset value, between an output value of the film thickness sensor when an underlayer of the layer to be polished is exposed and an output value of the film thickness sensor when the substrate is not present, the first offset value being associated with the identification information of the substrate,
• wherein the second substrate polishing apparatus:
• stores information of the first offset value in a memory;
• corrects an output value from the film thickness sensor based on the first offset value associated with the same identification information of the substrate that is measured by the film thickness sensor of the second substrate polishing apparatus;
• and
• outputs a control signal indicating an end point of substrate polishing when a measured value of the film thickness of each of the layers to be polished calculated based on the corrected output value reaches a target value.

A substrate polishing apparatus comprising:

• a polishing head for polishing a layer to be polished by pressing a substrate comprising the layer to be polished against a polishing pad;
• a film thickness sensor for measuring a film thickness of the layer to be polished;
• a memory that stores therein information indicating a difference, as a first offset value, between an output value of the film thickness sensor when an under layer of the layer to be polished is exposed and an output value of the film thickness sensor when the substrate is not present in past polishing of the layer to be polished, the first offset value being associated with the identification information of the substrate;
• a controller in communication with the memory, the controller configured to correct the output value from the film thickness sensor based on the first offset value associated with the same identification information of the substrate that is measured by the film thickness sensor of the second substrate polishing apparatus;
• and
• output a control signal indicating an end point of substrate polishing when a measured value of the film thickness of the layer to be polished based on the corrected output value reaches a target value.