In situ estimation of blanket polish rates and wafer-to-wafer variation

• Published in: IEEE transactions on semiconductor manufacturing Vol. 15; no. 4; pp. 513 - 522
• Main Authors: Patel, N.S., Miller, G.A., Jenkins, S.T.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2002; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Blanketing; Chemical-mechanical polishing; Chemicals; Data mining; Electronics; Estimates; Exact sciences and technology; Interferometry; Metrology; Microelectronic fabrication (materials and surfaces technology); Observability; Optical films; Process control; Production; Regression; Robustness; Sampling; Sampling methods; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Wafers; nonlinear regression; Microelectronic fabrication; Non linear regression; Process control; In situ; Chemical-mechanical polishing (CMP); Algorithm; Chemical mechanical polishing; Interferometry
• ISSN: 0894-6507; 1558-2345
• DOI: 10.1109/TSM.2002.804900

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.