摘要 |
A wafer stage system moves a wafer stage that retains a wafer via a wafer holder along a wafer base. For example, the wafer holder is formed from a material whose density is not uniform, such that the portion that includes the reflecting surface that reflects a measuring beam for position measurement is a high-density portion, and the other portions are low-density portions. Or, the wafer stage is formed from a material whose density is not uniform, such that the portion that includes the surface that constitutes a gas bearing is a high-density portion, and the other portions are low-density portions.
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