Specific Process Knowledge/Lithography/EBeamLithography/BEAMER: Difference between revisions
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The ''Advanced'' pane | The ''Advanced'' pane allows one to divide a design into different regions and apply different fracturing methods to different regions. Simply shift-click in the layout to draw out regions. It can also be used to assign different methods by layer. Multiple setups can be added with the ''+'' button. | ||
''Field Traversal:'' ''Fixed'', ''Floating'' or ''Fields Follow Geometry''. The ''Fixed'' traversal will lay out main fields in a perfect grid starting from the bottom left feature of the design. The ''Floating'' field option will attempt to place geometry in the center of writing fields and is best used for sparse layouts. ''Fields Follow'' will attempt to lay out fields and their writing order such that they follow geometry. This is a good choice for waveguides and spiral structures. | |||
''Multipass Mode:'' In order to mitigate beam fluctations it is possible to divide an exposure into multiple exposures of each writing field. It is a simple averaging technique whare each pattern element is written n times, each time with 1/n of the total dose. Options are ''Single Pass'', ''Two Passes'', ''Four Passes'' and ''Dose Selective''. In the first three cases the pattern is written in either one pass (i.e. not multipass), two passes or four passes. In the dose selective approach it is possible to set the number of passes based on the dose using the table in the bottom of the window. When using multipass one must assign either a ''Mainfield Offset'', a ''Subfield Offset'' or both, such that elements are written at different placements of the writing field. | |||