Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 02 processing: Difference between revisions
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==High Aspect Ratio (DOF) mode== | ==High Aspect Ratio (DOF) mode== | ||
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. In order to | 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. 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. | ||
[[Image:MLA150_intensityVSaperture.JPG|400x400px|thumb|The exposure intensity of Aligner: Maskless 02 as a function of the high AR mode aperture setting]] | [[Image:MLA150_intensityVSaperture.JPG|400x400px|thumb|The exposure intensity of Aligner: Maskless 02 as a function of the high AR mode aperture setting]] | ||