US 11,911,867 B2
Polishing apparatus and polishing method
Toshifumi Kimba, Tokyo (JP); Masaki Kinoshita, Tokyo (JP); and Yoichi Shiokawa, Tokyo (JP)
Assigned to EBARA CORPORATION, Tokyo (JP)
Filed by EBARA CORPORATION, Tokyo (JP)
Filed on Jul. 18, 2018, as Appl. No. 16/039,065.
Claims priority of application No. 2017-142578 (JP), filed on Jul. 24, 2017.
Prior Publication US 2019/0022820 A1, Jan. 24, 2019
Int. Cl. B24B 37/005 (2012.01); B24B 49/12 (2006.01); G01B 11/06 (2006.01)
CPC B24B 37/005 (2013.01) [B24B 49/12 (2013.01); G01B 11/0625 (2013.01); G01B 11/0683 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A polishing apparatus comprising:
a polishing table for supporting a polishing pad, the polishing table being rotatable;
a polishing head configured to press a wafer against the polishing pad;
a light source configured to emit light;
an illuminating fiber coupled to the light source and having a distal end disposed in a flow passage formed in the polishing table;
a spectrometer configured to resolve reflected light from the wafer in accordance with wavelengths and measure an intensity of the reflected light at each of the wavelengths;
a light-receiving fiber coupled to the spectrometer and having a distal end disposed in the flow passage;
a processor configured to determine a film thickness of the wafer based on a spectral waveform indicating a relationship between intensity and wavelength of the reflected light;
a liquid supply line communicating with the flow passage;
a gas supply line communicating with the flow passage;
a liquid supply valve attached to the liquid supply line;
a gas supply valve attached to the gas supply line; and
an operation controller configured to instruct the gas supply valve to open and instruct the liquid supply valve to close when the light-receiving fiber receives the reflected light from the wafer and when the polishing head presses the wafer against the polishing pad in each rotation of the polishing table, the operation controller being further configured to instruct the gas supply valve to close and instruct the liquid supply valve to open when the light-receiving fiber does not receive the reflected light from the wafer and when the polishing head presses the wafer against the polishing pad in each rotation of the polishing table.