Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 03 processing: Difference between revisions
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==Writing speed== | ==Writing speed== | ||
According to specs, the writing speed of Aligner: Maskless 03 is 1100mm<sup>2</sup>/min in fast mode. Using the high quality exposure mode cuts this speed in half, to approximately 550mm<sup>2</sup>/min. The writing speed for a 100x100mm<sup>2</sup> area measured during installation of the machine (acceptance test) was ~ | According to specs, the writing speed of Aligner: Maskless 03 is 1100mm<sup>2</sup>/min in fast mode. Using the high quality exposure mode cuts this speed in half, to approximately 550mm<sup>2</sup>/min. The writing speed for a 100x100mm<sup>2</sup> area measured during installation of the machine (acceptance test) was ~1200mm<sup>2</sup>/min. | ||
'''Speed vs. area:''' | |||
During exposure of a stripe the stage moves at a constant speed. Each stripe thus includes a certain movement overhead for acceleration and deceleration. As the stripes get shorter, this overhead becomes more significant, and the normal writing speed is no longer achieved. For samples smaller than a 2" wafer, the writing speed of Aligner: Maskless 02 drops below the specified 285mm<sup>2</sup>/min. | |||
When the exposure is started on the maskless aligner, the software starts converting the design to the data needed for the exposure. When sufficient data has been generated, the hardware starts exposing the sample while more data is being generated. This simultaneous data conversion and exposure is called Online conversion. Once a design has been converted (exposed) the data may be reused for repeated exposures (Offline conversion). However, the converted data can only be reused if no alignment is needed, including flat alignment ("Expose with substrate angle"). Due to the powerful, separate conversion PC on Aligner: Maskless 03, offline exposure is only very slightly faster than online. | |||
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'''Speed vs. dose:''' | |||
The writing speed remains almost constant up to a dose of 1000mJ/cm<sup>2</sup>. Due to the higher power of the 405nm laser, the writing speed remains high up to a dose of 2000mJ/cm<sup>2</sup> for this wavelength. After this point, the writing speed decreases almost linearly with dose. For 375nm, the writing speed is 50% at a dose of 4500mJ/cm<sup>2</sup>, while 405nm requires a dose of 8500mJ/cm<sup>2</sup> to drop to that speed. | |||
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==Acceptance test== | ==Acceptance test== | ||