Specific Process Knowledge/Lithography/EBeamLithography/eLINE: Difference between revisions
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==Typical beam currents== | ==Typical beam currents== | ||
Beam current is a function of acceleration voltage and aperture and thus beam current is locked by the choice of acceleration voltage and aperture. Typical beam currents are given in the table below. | Beam current is a function of acceleration voltage and aperture and thus beam current is locked by the choice of acceleration voltage and aperture. Typical beam currents are given in the table below. The High Current (HC) mode can be activated in the Column Control panel. | ||
The High Current (HC) mode can be activated in the Column Control panel. | |||
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| style="background:WhiteSmoke; color:black"| 12.6 | | style="background:WhiteSmoke; color:black"| 12.6 | ||
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Writing time can be estimated in the software once a job is defined, it is however straight forward to estimate in advance based on area to pattern, A, dose to clear, d0, and beam current, I as: | |||
T = d0*A/I | |||
Notice that this estimate is only the beam dwell time and does not account for beam settling time or stage movement time. Typically process times are 3-4 times higher than the dwell time estimate but this will vary with pattern and writing conditions. | |||
==Writing fields== | ==Writing fields== | ||
Writefield dimension is a trade off between beam shot precision and field stitching. The maximum writefield size is 1000x1000 µm. The beam controller has a limit of 50000 addressable positions along each axis and hence for a 1000x1000 µm writefield the minimum beam pitch is 20 nm. For a 100x100 µm writefield the minimum beam pitch is 2 nm. Thus the precision is higher for smaller writing fields. Smaller writing fields will however fracture a design into more fields and create more field boundaries with higher potential for stitching errors. | Writefield dimension is a trade off between beam shot precision and field stitching. The maximum writefield size is 1000x1000 µm. The beam controller has a limit of 50000 addressable positions along each axis and hence for a 1000x1000 µm writefield the minimum beam pitch is 20 nm. For a 100x100 µm writefield the minimum beam pitch is 2 nm. Thus the precision is higher for smaller writing fields. Smaller writing fields will however fracture a design into more fields and create more field boundaries with higher potential for stitching errors. | ||