Specific Process Knowledge/Lithography/EBeamLithography/JEOLPatternPreparation: Difference between revisions
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The proximity effect comes from backscattered electrons that will provide a secondary exposure to the resist. Thus the exposure dose received by the resist has two components; the intentional exposure from the incident beam and an undesireable exposure from backscaterred electrons. The distance of which this secondary exposure will occur is dependent on substrate material and acceleration voltage. For silicon substrates exposed at 100 kV, the distance is up to 30 µm. The amount of secondary exposure will be pattern dependent since densely populated pattern areas will suffer a lot of secondary exposure while sparsely populated areas will not suffer much secondary exposure. This will cause a local pattern bias that will depend on local pattern load. In order to circumvent this one can modulate the incident dose to account for the proximity effect. The dose modulation can be calculated with Beamer. Beamer will essentially break the design into a number of dose classes and assign each a unique dose dependent on pattern density and feature dimension. | The proximity effect comes from backscattered electrons that will provide a secondary exposure to the resist. Thus the exposure dose received by the resist has two components; the intentional exposure from the incident beam and an undesireable exposure from backscaterred electrons. The distance of which this secondary exposure will occur is dependent on substrate material and acceleration voltage. For silicon substrates exposed at 100 kV, the distance is up to 30 µm. The amount of secondary exposure will be pattern dependent since densely populated pattern areas will suffer a lot of secondary exposure while sparsely populated areas will not suffer much secondary exposure. This will cause a local pattern bias that will depend on local pattern load. In order to circumvent this one can modulate the incident dose to account for the proximity effect. The dose modulation can be calculated with Beamer. Beamer will essentially break the design into a number of dose classes and assign each a unique dose dependent on pattern density and feature dimension. | ||
PEC is calculated based on a Point Spread Function (PSF). The PSF is a model of the radial electron energy density received by the resist around the incident beam. | |||
== Pattern fracturing == | == Pattern fracturing == | ||
== Field sorting == | == Field sorting == | ||
== Export for writing == | == Export for writing == | ||