Specific Process Knowledge/Lithography/EBeamLithography/JEOLPatternPreparation: Difference between revisions
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== Pattern placement == | == Pattern placement == | ||
Pattern placement on the JEOL system has a very important difference regarding patttern placement compared to our Heidelberg MLA systems. Pattern placement is entirely dependent on the boundary box of the design. All patterns are placed using the '''ARRAY''' command and they are placed with respect to the center of the design boundary box. This is illustrated below with the two designs, L1 and L2. L1 is a design nicely centered around (0,0) with a symmetric bounding box. When placed by the '''ARRAY''' command at (0,0) this will come out entirely as expected. L2 does however not have a bounding box centered around (0,0) and when placed by the '''ARRAY''' command at (0,0), it will be exposed at the center of the substrate. Thus, it is vital to keep the bounding box in mind as the '''ARRAY command places patterns with respect to the center of the bounding box.''' This is in stark contrast to how the MLA UV lithography systems work and it is often essential to intentionally control the bounding box of a pattern. | Pattern placement on the JEOL system has a very important difference regarding patttern placement compared to our Heidelberg MLA systems. Pattern placement is entirely dependent on the boundary box of the design. The boundary box is simply defined as the smallest box enclosing the entire design. All patterns are placed using the '''ARRAY''' command and they are placed with respect to the '''center of the design boundary box.''' This is illustrated below with the two designs, L1 and L2. L1 is a design nicely centered around (0,0) with a symmetric bounding box. When placed by the '''ARRAY''' command at (0,0) this will come out entirely as expected. L2 does however not have a bounding box centered around (0,0) and when placed by the '''ARRAY''' command at (0,0), it will be exposed at the center of the substrate. Thus, it is vital to keep the bounding box in mind as the '''ARRAY command places patterns with respect to the center of the bounding box.''' This is in stark contrast to how the MLA UV lithography systems work and it is often essential to intentionally control the bounding box of a pattern. | ||
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=== Boundary box control === | === Boundary box control === | ||
In continuation of the example above, if two layers/exposures are to be aligned to each other in subsequent process steps it is vital to control the extend of the boundary box, since that the two layers boundary boxes are identical or at least symmetric around (0,0). With reference to the example below, the boundary boxes can be made identical by either | In continuation of the example above, if two layers/exposures are to be aligned to each other in subsequent process steps it is vital to control the extend of the boundary box, since '''the ARRAY command places patterns with respect to the center of the bounding box'''. | ||
that the two layers boundary boxes are identical or at least symmetric around (0,0). With reference to the example below, the boundary boxes can be made identical by either | |||
*Letting L2 inherit the L1 boundary box (option in Beamer) | *Letting L2 inherit the L1 boundary box (option in Beamer) | ||