Systems and methods that control liquid temperature in immersion lithography to maintain temperature gradient to reduce turbulence

摘要

The subject invention provides systems and methods that monitor and/or control turbulence of an immersion medium. The systems and methods relate to computer controlled techniques that reduce effects of immersion medium flow due to a liquid temperature gradient. According to an aspect of the subject invention, a number of temperature measurements of the immersion medium are obtained, and the temperature measurements are utilized to generate a gradient map of the immersion medium. By way of illustration, the temperature measurements can be made via wireless temperature sensors. The gradient map can be utilized to understand the stability of the immersion medium. According to an aspect of the subject invention, instability identified with the gradient map can be mitigated.