9 December 2005 Interferometric thickness calibration of 300 mm silicon wafers
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Proceedings Volume 6024, ICO20: Optical Devices and Instruments; 602426 (2005) https://doi.org/10.1117/12.666951
Event: ICO20:Optical Devices and Instruments, 2005, Changchun, China
Abstract
The "Improved Infrared Interferometer" (IR3) at the National Institute of Standards and Technology (NIST) is a phase-measuring interferometer, operating at a wavelength of 1550 nm, which is being developed for measuring the thickness and thickness variation of low-doped silicon wafers with diameters up to 300 mm. The purpose of the interferometer is to produce calibrated silicon wafers, with a certified measurement uncertainty, which can be used as reference wafers by wafer manufacturers and metrology tool manufacturers. We give an overview of the design of the interferometer and discuss its application to wafer thickness measurements. The conversion of optical thickness, as measured by the interferometer, to the wafer thickness requires knowledge of the refractive index of the material of the wafer. We describe a method for measuring the refractive index which is then used to establish absolute thickness and thickness variation maps for the wafer.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Quandou Wang, Quandou Wang, Ulf Griesmann, Ulf Griesmann, Robert Polvani, Robert Polvani, } "Interferometric thickness calibration of 300 mm silicon wafers", Proc. SPIE 6024, ICO20: Optical Devices and Instruments, 602426 (9 December 2005); doi: 10.1117/12.666951; https://doi.org/10.1117/12.666951
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