Specific Process Knowledge/Lithography/EBeamLithography/BEAMER: Difference between revisions
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===Fracture=== | ===Fracture=== | ||
Before pattern writing the polygons of a design must be fractured into trapezoids filled with beam/shot positions. Careful setup of how a design is fractured and shots are placed can greatly enhance the end result both in terms of critical dimension accuracy, line edge roughness and pattern stitching between writing fields. | Before pattern writing the polygons of a design must be fractured into trapezoids filled with beam/shot positions. Careful setup of how a design is fractured and shots are placed can greatly enhance the end result both in terms of critical dimension accuracy, line edge roughness and pattern stitching between writing fields. The ''Fracture'' node has three main panes, ''General'', ''Advanced'' and ''Fields'' (if using ''Flat with Fields''). The options found on the ''General'' pane are: | ||
The ''Fracture'' node has three main panes, ''General'', ''Advanced'' and ''Fields'' (if using ''Flat with Fields''). The options found on the ''General'' pane are: | |||
''Maintain grid:'' Check this to fracture at the database grid size, in most cases 1 nm. If unchecked the fracturing resolution can be changed in the ''Resolution'' field. The fracture resolutions should be set to the writing grid resolution, in most cases 1 nm. | ''Maintain grid:'' Check this to fracture at the database grid size, in most cases 1 nm. If unchecked the fracturing resolution can be changed in the ''Resolution'' field. The fracture resolutions should be set to the writing grid resolution, in most cases 1 nm. | ||
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''Beam Step Size Correction:'' | ''Beam Step Size Correction:'' | ||
''Fracture modes'' | |||
Fracture modes | |||
*''Conventional:'' The conventional algorithm performs mainly horizontal fractures at polygon vertices that maintain the original design intent as good as possible. This leads to many slices of trapezoids to best represent the original layout. | *''Conventional:'' The conventional algorithm performs mainly horizontal fractures at polygon vertices that maintain the original design intent as good as possible. This leads to many slices of trapezoids to best represent the original layout. | ||
*''Large Rectangle Fine Trapezoid:'' The LRFT algorithm attempts to minimize the number of shapes using very large rectangles for large areas and fine trapezoids for smaller features. In other words, this mode fractures the polygons with as many large rectangles as possible and completes the filling with small trapezoids. | *''Large Rectangle Fine Trapezoid:'' The LRFT algorithm attempts to minimize the number of shapes using very large rectangles for large areas and fine trapezoids for smaller features. In other words, this mode fractures the polygons with as many large rectangles as possible and completes the filling with small trapezoids. | ||