US 12,416,490 B1
Method and chemical mechanical planarization device for in-situ measurement of film thickness
Weitao Meng, Beijing (CN); Huiyan Zhou, Beijing (CN); and Jile Jiang, Beijing (CN)
Assigned to BEIJING TSD SEMICONDUCTOR CO., LTD., Beijing (CN)
Filed by BEIJING TSD SEMICONDUCTOR CO., LTD., Beijing (CN)
Filed on Feb. 21, 2025, as Appl. No. 19/060,371.
Application 19/060,371 is a continuation of application No. PCT/CN2024/135879, filed on Nov. 29, 2024.
Claims priority of application No. 202410682381.X (CN), filed on May 29, 2024.
Int. Cl. G01B 11/06 (2006.01); B24B 37/013 (2012.01); B24B 49/12 (2006.01); H01L 21/304 (2006.01); H01L 21/66 (2006.01)
CPC G01B 11/0625 (2013.01) [B24B 37/013 (2013.01); B24B 49/12 (2013.01); H01L 21/304 (2013.01); H01L 22/26 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for in-situ measurement of film thickness, applied to semiconductor processing in a chemical mechanical polishing (CMP) environment, comprising the following steps:
generating a measured spectrum based on a reflection spectrum of a wafer film of a wafer and an equivalent light source spectrum, wherein the equivalent light source spectrum is data of a correspondence between wavelength and light intensity generated using reflected light passing through a slurry and a dielectric layer between the slurry and a collimated light source probe with the slurry added to a polishing pad before placing the wafer on the carrier; and the dielectric layer comprises a light-transmitting sealing layer disposed on a polishing disc and the polishing pad, and a bulk water layer formed by the slurry;
matching the measured spectrum with a reference spectrum library, wherein the reference spectrum library is a collection of reference spectra generated for given thicknesses of the wafer film using a spectrum computation model, or the reference spectra are measured data; the measured data are spectra collected for a wafer film of known thickness; and the thickness of the wafer film is measured using a non-spectral, contact, or non-contact instrument and method; and
obtaining a thickness of the wafer film corresponding to a reference spectrum that matches the measured spectrum as a detection result;
monitoring in real time whether a thickness of a wafer film reaches a target thickness; and
stopping grinding when the thickness of the wafer film reaches the target thickness.