Specific Process Knowledge/Lithography/EBeamLithography: Difference between revisions
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= Proximity Error Correction = | = Proximity Error Correction (PEC) = | ||
Even though the electron beam diameter is only a few nm, the feature and pitch resolution in resist is limited by the forward and backward scattering of the electrons in the resist and substrate material. | |||
Forward scattering is scattering within the resist layer and it will have a broadening effect of the beam. The magnitude of this effect depends on acceleration voltage, resist composition and thickness of the resist layer. | |||
Back scattering is caused by electron-matter interaction in the substrate itself and electrons that are scattered back into the resist layer will provide a secondary (unwanted) exposure of the resist. The scattering distance is highly dependent on acceleration voltage and the substrate material. | |||
As the travel distance of backscattered electrons is fairly large, e-beam patterned structures will be influenced by adjacent e-beam patterned structures, i.e. a proximity effect. These proximity effects can be avoided either by simulating a proximity error correction (PEC) in BEAMER or by using the right stack of e-beam resist. | As the travel distance of backscattered electrons is fairly large, e-beam patterned structures will be influenced by adjacent e-beam patterned structures, i.e. a proximity effect. These proximity effects can be avoided either by simulating a proximity error correction (PEC) in BEAMER or by using the right stack of e-beam resist. | ||