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Development of Metal Impurities Monitor Using LIBS Technology
by Yoshitada Ito1, Takashi Ono1, Rakesh Bhandari, Ph.D.1, Hideshi Yamaguchi2, and Masahiro Ihara3
(Received January 9, 2018)
We have developed and commercialized a metal impurities monitor system using laser induced breakdown spectro-scopy (LIBS) technology for semiconductor manufacturing processes.
The system can detect and determine the concentrations of minute metal elements in the liquid used in the cleaning process for removing impurities or metal elements that become attached to the wafer surface during the semiconductor manufacturing process. By monitoring the metal element concentrations in the cleaning liquid, the quantity of liquid and its exchange frequency can be reduced, so that the cleaning liquid can be used to its maximum. The reduction in the quantity of cleaning liquid that is used results in reduced disposal, contributing to a less adverse effect on the environment and to better process control because the exchange period of the cleaning liquid can be estimated.
This report describes the background to the development, outlines the system and its configuration, gives examples of metal detection, and offers prospects for the future.
Keywords: Laser induced breakdown spectroscopy (LIBS), Laser, Spectrum, Cleaning process, Semiconductor, Environment
1Sensor Device Business Unit, Device Department, Shimadzu Corporation, Kyoto, Japan
2Quality Assurance Group, Device Department, Shimadzu Corporation, Kyoto, Japan
3Optical Technology Unit, Technology Research Laboratory, Shimadzu Corporation, Kyoto, Japan
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