Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 02 processing: Difference between revisions
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It is possible to combine this feature with other features, such as high aspect ratio mode. | It is possible to combine this feature with other features, such as high aspect ratio mode. | ||
==High Aspect Ratio (DOF) mode== | ==<del>High Aspect Ratio (DOF) mode</del>== | ||
<span style="color:red">OBS: After the new writehead was installed in 2023, this feature was never fully adjusted, and never tested. Re-establishing the function will require significant effort.</span> | <span style="color:red">OBS: After the new writehead was installed in 2023, this feature was never fully adjusted, and never tested. Re-establishing the function will require significant effort.</span> | ||
'''Obsolete information about the HAR feature:''' | |||
Aligner: Maskless 02 is configured with the so-called "Write Mode I", which uses a higher demagnification, higher NA lens system to achieve higher resolution. This reduces the depth of focus (technically ''depth of field''), making it more difficult to achieve good lithographic results in thicker resist coatings. The theoretical DOF of Aligner: Maskless 02 is 0.3µm, compared to 1µm for Aligner: Maskless 01 and Aligner: Maskless 03. In order to improve processing of thick resists, the Aligner: Maskless 02 has been configured with the High Aspect Ratio Mode, which uses a variable aperture in the optical path to decrease the (illumination) NA of the system, thus increasing the DOF at the expense of intensity and resolution limit. | Aligner: Maskless 02 is configured with the so-called "Write Mode I", which uses a higher demagnification, higher NA lens system to achieve higher resolution. This reduces the depth of focus (technically ''depth of field''), making it more difficult to achieve good lithographic results in thicker resist coatings. The theoretical DOF of Aligner: Maskless 02 is 0.3µm, compared to 1µm for Aligner: Maskless 01 and Aligner: Maskless 03. In order to improve processing of thick resists, the Aligner: Maskless 02 has been configured with the High Aspect Ratio Mode, which uses a variable aperture in the optical path to decrease the (illumination) NA of the system, thus increasing the DOF at the expense of intensity and resolution limit. | ||