Method for inspecting a polishing pad in a semiconductor manufacturing process, an apparatus for performing the method, and a polishing device adopting the apparatus
AssigneeSamsung Electronics Co., Ltd.
InventorsChung-Sam Jun, Kye-Weon Kim, Yu-Sin Yang, Hyo-Hoo Kim
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Abstract
A method for inspecting a polishing pad, an apparatus for performing the method, and a polishing device adopting the apparatus for preventing wafer defects. Polishing pad defects are detected by comparing optical data from a normal polishing pad, which does not cause wafer defects, with optical data from a polishing pad to be inspected. The respective optical data are obtained by radiating a beam into the polishing pad and then collecting and analyzing a beam reflected from the polishing pad.
Claims19
A method for inspecting a polishing pad, comprising:
- obtaining reference data from a surface of a reference polishing pad which is known to produce a defect-free wafer;
- radiating a beam onto a region extending across a radial unit area of the polishing pad to be inspected while rotating the polishing pad such that the radial unit area scan a surface of the rotating polishing pad;
- obtaining empirical optical data of the radial unit area scanning the surface of the polishing pad to be inspected;
- comparing the reference data with the empirical data to determine whether a defect is present in the radial unit area scanning the surface of the polishing pad;
- and
- determining a position of a defect in the polishing pad by using both a position of the defect in the radial unit area and a rotational angle of the polishing pad from a reference point.
The method as claimed in clam 1, further comprising smoothing the reference data and empirical data prior to comparing the reference data and empirical data, wherein the smoothing includes,
- dividing reference data and the empirical data into a plurality of data areas;
- obtaining an average reference data value and an average empirical data value from the respective data areas;
- and
- comprising the average reference data value and the average empirical data value.
An apparatus for inspecting a polishing pad, comprising:
- a stage for placing a polishing pad thereon, said stage including a rotating motor for rotating the stage;
- a beam source for radiating a beam onto a radial unit area of a surface of the polishing pad;
- an output part for continuously outputting an empirical optical data for image display of the radial unit area of the polishing pad;
- a defect detecting part connected to the output part for comparing reference data with the empirical data to determine whether a defect is present in the radial unit area of the polishing pad;
- and
- a defect position detecting part connected to the defect detecting part for determining a position of a defect in the polishing pad by using both a position of the defect in the radial unit area and a rotational angle of the polishing pad from a reference point.
A polishing device comprising:
- a polishing head which suctions a wafer and rotates while pressing the wafer;
- a platen which is rotated by a rotating shaft installed at a lower portion thereof and on which a polishing pad for polishing the wafer is attached;
- a beam source for radiating a beam onto a radial unit area in a surface of the polishing pad on the platen;
- an output part for continuously outputting an empirical data for image display of the radial unit area on the polishing pad;
- a defect detecting part connected to the output part for comparing reference data with the empirical data to determine whether a defect is present in the radial unit area of the polishing pad;
- and
- a defect position detecting part connected to the determine part state for determining a position of a defect in the polishing pad by using both a position of the defect in the radial unit area and a rotational angle of the polishing pad from a reference point.
Dependencies are inferred from the claim text.