In the semiconductor industry, the pursuit of smaller chip size and higher throughput requires the next-generation lithography machines to have higher acceleration with tight accuracy in a sub-nanometer level. There have been efforts to increase the reticle stage acceleration by replacing iron-less Lorentz motors [1] with iron-core permanent magnet motors. However, it is observed that conventional iron-core motors emit a significant amount of noise, which is transmitted in both structural- and air-borne pathways. Such vibrations can disturb the lens and metrology-frame, thereby deteriorating the lithography system accuracy performance.
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