Method for correcting electronic proximity effects using off-center scattering functions
AssigneesCommissariat A L'energie Atomique Et Aux Energies Alternatives, Aselta Nanographics
InventorsPatrick Schiavone, Thiago Figueiro
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Abstract
A method for projecting an electron beam, used notably in direct or indirect writing lithography and in electronic microscopy. Proximity effects created by the forward and backward scattering of the electrons of the beam in interaction with the target must be corrected. For this, the convolution of a point spread function with the geometry of the target is conventionally used. At least one of the components of the point spread function has its maximum value not located on the center of the beam. Preferably, the maximum value is instead located on the backward scattering peak. Advantageously, the point spread function uses gamma distribution laws.
Claims12
A method for projecting an electron beam onto a target comprising:
- a step of correcting effects of forward and backward scattering of said beam comprising a substep of calculating a point spread function, wherein said point spread function comprises at least one function, a maximum amplitude value of which is not located on a center of the beam;
- and
- modulating dosage of the electron beam based upon at least the point spread function.
A non-transitory computer-readable media comprising program code that is configured to be executable by a computer to provide a module for simulating or correcting effects of forward and backward scattering of an electron beam, said module comprising a submodule for calculating a point spread function, wherein said point spread function comprises at least one function, a maximum amplitude value of which is not located on a center of the electron beam, the point spread function being used for modulation of a dosage of the electron beam.
Dependencies are inferred from the claim text.