Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 04 processing: Difference between revisions
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The site acceptance test performed during the installation of the Aligner: Maskless 04 showed an exposure speed of 47mm<sup>2</sup>/min, which is slightly higher than the 40mm<sup>2</sup>/min given in the specifications. At such speeds, a full 4" design would take 2:45-3:15 hours to expose. | The site acceptance test performed during the installation of the Aligner: Maskless 04 showed an exposure speed of 47mm<sup>2</sup>/min, which is slightly higher than the 40mm<sup>2</sup>/min given in the specifications. At such speeds, a full 4" design would take 2:45-3:15 hours to expose. | ||
The exposure time increases linearly with exposure dose and writing area. However, due to the stepped nature of the exposure, the exposure time as a function of fill factor is highly nonlinear. It takes the same time to expose a single pixel as the entire writing field, so the exposure time depends on the number of addressed writing fields, rather than on the fill factor of the design. In practice, there will probably not be much variation in exposure time with fill factor. Exposure tests have shown that the exposure speed is low for small areas, but reaches full speed at areas above 40x40mm<sup>2</sup>. The lower speed for small areas is probably due to the delay in exposure start caused by the generation of the data needed for the exposure (conversion). Exposure tests using a 25mm<sup>2</sup> design have shown that the exposure time increases linearly from 37s at 10mJ/cm<sup>2</sup> | The exposure time increases linearly with exposure dose and writing area. However, due to the stepped nature of the exposure, the exposure time as a function of fill factor is highly nonlinear. It takes the same time to expose a single pixel as the entire writing field, so the exposure time depends on the number of addressed writing fields, rather than on the fill factor of the design. In practice, there will probably not be much variation in exposure time with fill factor. Exposure tests have shown that the exposure speed is low for small areas, but reaches full speed at areas above 40x40mm<sup>2</sup>. The lower speed for small areas is probably due to the delay in exposure start caused by the generation of the data needed for the exposure (conversion). Exposure tests using a 25mm<sup>2</sup> design have shown that the exposure time increases linearly with dose, from 37s at 10mJ/cm<sup>2</sup> to 252s at 2000mJ/cm<sup>2</sup>. | ||
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The Vector mode will write structures line by line. Structures will have low edge roughness and there will be no stitching of long lines. However, write time of a given design will strongly depend on the number, shape, or size of structures. | The Vector mode will write structures line by line. Structures will have low edge roughness and there will be no stitching of long lines. However, write time of a given design will strongly depend on the number, shape, or size of structures. | ||
The exposure time is a function of the number of elements (lines) in the design and the stage velocity during exposure. While the maximum velocity of the stage is 200mm/s | 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 | |||
==Resolution== | ==Resolution== | ||