Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 04 processing: Difference between revisions
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The exposure time is a function of the number of elements (lines) in the design and the stage velocity during exposure. While a very low Exposure Velocity will of course slow down the exposure speed, a high velocity will also lower the exposure speed because the stage has to accelerate longer before the exposure of each element can start. The maximum velocity of the stage is 200mm/s but Heidelberg recommend not to exceed 120mm/s, in order to avoid distortions of the elements due to acceleration effects. | The exposure time is a function of the number of elements (lines) in the design and the stage velocity during exposure. While a very low Exposure Velocity will of course slow down the exposure speed, a high velocity will also lower the exposure speed because the stage has to accelerate longer before the exposure of each element can start. The maximum velocity of the stage is 200mm/s but Heidelberg recommend not to exceed 120mm/s, in order to avoid distortions of the elements due to acceleration effects. | ||
<br>During exposure tests of different sizes of simple square designs, the | <br>During exposure tests of different sizes of simple square designs, the optimal stage velocity (in terms of exposure time) increased linearly from 15mm/s for 0.5mm elements to 50mm/s for 5mm elements. The highest "exposure speed" was just below 4 elements per second, which was observed for the 0.5mm elements. In practice, exposure can't always be at the optimal Exposure Velocity, as it may be necessary to decrease the velocity in order to achieve the required dose. | ||
==Resolution== | ==Resolution== | ||