Abstract: A method for preparing a pattern to be printed on a plate or mask by electron beam lithography comprising the following steps: modelling of the pattern by breaking down this pattern into a set of elementary geometric shapes intended to be printed individually in order to reproduce said pattern and, for each elementary geometric shape of the model; determination of an electrical charge dose to be applied to the electron beam during the individual printing of the elementary shape, this dose being chosen from a discrete set of doses including several non-zero predetermined doses recorded in memory. The set of elementary geometric shapes is a bidimensional paving of identical elementary geometric shapes covering the pattern to be printed. In addition, when the doses to be applied to the elementary geometric shapes are determined, a discretisation error correction is made by dithering.

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.