| 摘要 |
The present invention relates to an apparatus for measuring a wafer layer thickness in a chemical mechanical polishing apparatus and a method thereof. The method of measuring a wafer layer thickness, which is used in a chemical mechanical polishing apparatus including a polishing pad and a transparent window formed at a place at which a polishing plate is perforated and by which the chemical mechanical polishing process of a wafer is performed while a plate surface of the wafer makes contact with the polishing pad, includes a receiving light data obtaining step of obtaining receiving light data by receiving a first reflected light reflected on the polishing surface of the water and a second reflected light reflected on a lower surface of the polishing plate wearing the polishing pad by irradiating light from a light radiating unit placed at a lower side of the wafer during the chemical mechanical polishing process; a compensation data generating step of generating compensation data by filtering the receiving light data based on the second reflected light from the receiving light data; and a layer thickness determining step of determining the wafer layer thickness based on the compensation data. Thus, the method and the apparatus for measuring a wafer layer thickness in a chemical mechanical polishing apparatus, which is capable of exactly measuring the layer thickness of a wafer in real time during a chemical mechanical polishing process in an in situ scheme, can be provided. [Reference numerals] (AA) Receiving light signal amplitude; (BB) Frequency |
