Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 01 processing: Difference between revisions
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The site acceptance test performed during the installation of the Aligner: Maskless 01 showed an exposure time/speed of 0.025 min/ | The site acceptance test performed during the installation of the Aligner: Maskless 01 showed an exposure time/speed of 0.025 min/mm<sup>2</sup>, which is slightly lower than the 0.02 min/mm<sup>2</sup> given in the specifications. At such speeds, a full 4" design would take 2.6-3.3 hours to expose. In practice, we observe exposure times in excess of 2 hours for a full 4" design. | ||
At such exposure speeds, we would quickly run into a bottleneck as more and more users expose more and more wafers, if full 4" designs are used all the time. Another concern is that the exposure dose seems to be unstable over long exposure times, as consecutive exposures using the same parameters have been observed to yield different lithographic results. The conclusion is that exposure using the maskless aligner requires a different design philosophy than when a mask aligner is used for the exposure. | At such exposure speeds, we would quickly run into a bottleneck as more and more users expose more and more wafers, if full 4" designs are used all the time. Another concern is that the exposure dose seems to be unstable over long exposure times, as consecutive exposures using the same parameters have been observed to yield different lithographic results. The conclusion is that exposure using the maskless aligner requires a different design philosophy than when a mask aligner is used for the exposure. | ||