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. | ||
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. | |||
*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. | |||
*Curved: This algorithm should typically be used to fracture circles and rings. This mode allows BEAMER to shift the vertices along curves to get fractures consistent with the specified resolution and beam step size. In other words, this mode will try to detect curves in the given polygons and fracture these curves within a specified tolerance consistent with the specified resolution and beam step size. | |||
===ChipPlace=== | ===ChipPlace=== | ||