Title :
In situ estimation of blanket polish rates and wafer-to-wafer variation
Author :
Patel, Nital S. ; Miller, Gregory A. ; Jenkins, Steven T.
Author_Institution :
Texas Instrum. Inc., Dallas, TX, USA
fDate :
11/1/2002 12:00:00 AM
Abstract :
Presents a scheme for extracting information from interferometry signals off patterned wafer polish during nonendpointed chemical-mechanical polishing (CMP). This enables one to obtain blanket removal rates immediately after a patterned wafer finishes polishing as well as estimate post-polish within lot thickness variation. A nonlinear regression algorithm is presented that enables one to estimate this information from less than a full interferometry trace cycle and with a lower sampling rate compared to peak-valley detection schemes.
Keywords :
chemical mechanical polishing; light interferometry; planarisation; process control; statistical analysis; blanket polish rates; blanket removal rates; interferometry signals; interferometry trace cycle; lot thickness variation; nonendpointed chemical-mechanical polishing; nonlinear regression algorithm; post-polish estimation; sampling rate; wafer-to-wafer variation; Chemicals; Data mining; Interferometry; Metrology; Observability; Optical films; Process control; Production; Robustness; Sampling methods;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
DOI :
10.1109/TSM.2002.804900
