This paper describes a double pass surface encoder, composed of a 2D sinusoidal grid and an optical sensor, for nanometer position measurement in the XY plane. By using a double pass optical layout, the sensitivity becomes twice as much as that of the single pass encoder. From a wave optics simulation, the grid amplitude of 70 nm is selected. The experimental result shows that the sensor has a resolution higher than 5 nm. The interpolation error is 0.6 μm in both the X- and 7-direction. The extrapolation errors in the X- and Y-direction are 0.18 μm and 0.23 μm.
|ジャーナル||International Journal of Surface Science and Engineering|
|出版ステータス||Published - 2007 1 1|
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