Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 02 processing: Difference between revisions
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'''Speed vs. design:''' | '''Speed vs. design:''' | ||
Depending on the complexity and density of the pattern, the conversion process may slow down the exposure significantly. A 4" wafer exposed with a pattern consisting of 200 million 5µm circles took 65 minutes (154mm<sup>2</sup>/min), compared to the specified 35 minutes (285mm<sup>2</sup>/min). | Depending on the complexity and density of the pattern, the conversion process may slow down the exposure significantly. A 4" wafer exposed with a pattern consisting of 200 million 5µm circles took 65 minutes (154mm<sup>2</sup>/min), compared to the specified 35 minutes (285mm<sup>2</sup>/min). It took 12 minutes before the first stripe was exposed. | ||
The maskless aligner exposes the design in north-south oriented stripes (perpendicular to the flat). The stripes all have the same length, set by the height of the design, and only completely empty stripes are skipped. The writing speed may thus be affected by the layout of the design, as shown below. | The maskless aligner exposes the design in north-south oriented stripes (perpendicular to the flat). The stripes all have the same length, set by the height of the design, and only completely empty stripes are skipped. The writing speed may thus be affected by the layout of the design, as shown below. | ||