Specific Process Knowledge/Lithography/EBeamLithography/EBLLandingpage: Difference between revisions
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=== Discharge layer application === | === Discharge layer application === | ||
As exposure is done with an electron beam, insulating substrates will cause a build up of charge that will deflect the incoming beam and disturb pattern definition. It is therefore necesarry when working with insulating substrates or substrates with thick (> 200 nm) dielectric films to apply a discharge layer. This is typically applied on top of the EBL resist layer and must be removed in between exposure and development. The most common discharge layer is 20 nm thermally evaporated Al. Bear in mind that it should be thermally evaporated and not e-beam evaporated. Thermal evaporation of Al can be done in [[Specific_Process_Knowledge/Thin film deposition/thermalevaporator|Thermal evaporator]] and [[Specific_Process_Knowledge/Thin film deposition/Wordentec|Wordentec]]. | As exposure is done with an electron beam, insulating substrates will cause a build up of charge that will deflect the incoming beam and disturb pattern definition. It is therefore necesarry when working with insulating substrates or substrates with thick (> 200 nm) dielectric films to apply a discharge layer. This is typically applied on top of the EBL resist layer and must be removed in between exposure and development. The most common discharge layer is 20 nm thermally evaporated Al. Bear in mind that it should be thermally evaporated and not e-beam evaporated. Thermal evaporation of Al can be done in [[Specific_Process_Knowledge/Thin film deposition/thermalevaporator|Thermal evaporator]] and [[Specific_Process_Knowledge/Thin film deposition/Wordentec|Wordentec]]. | ||
For samples with 2D materials such as graphene, HBN, etc., it is '''mandatory''' to apply a 20 nm Al layer on top of the resist in order to expose the substrate in the JEOL 9500 system. The Raith eLine system does not have this requirement. | |||
The Al layer can be removed with MIF726 after exposure. MIF726 etch rate in Al is about 0.5 nm/s, although only about 1 nm/min in oxidized aluminium. | The Al layer can be removed with MIF726 after exposure. MIF726 etch rate in Al is about 0.5 nm/s, although only about 1 nm/min in oxidized aluminium. | ||
Another possibility is to use a spin-on conductive layer such as AR-PC 5090. It can be removed with water after exposure. At the moment we do not have much experience with this, contact the EBL team if you are interested in this option. | Another possibility is to use a spin-on conductive layer such as AR-PC 5090. It can be removed with water after exposure. At the moment we do not have much experience with this, contact the EBL team if you are interested in this option. | ||
=== Inspection === | |||
== Development == | == Development == | ||