摘要:
L'invention s'applique à un procédé de projection d'un faisceau électronique (100) utilisé notamment en lithographie par écriture directe ou indirecte ainsi qu'en microscopie électronique. Notamment pour les dimensions critiques ou résolutions inférieures à 50 nm, les effets de proximité créés par la diffusion vers l'avant (150) et vers l'arrière (160) des électrons du faisceau en interaction avec la cible (110) doivent être corrigés. On utilise traditionnellement pour ce faire la convolution d'une fonction d'étalement de point avec la géométrie de la cible. Dans l'art antérieur, ladite fonction d'étalement de point est centrée sur le faisceau et utilise des lois de distribution gaussiennes ou exponentielle. Selon l'invention, au moins une des composantes de la fonction d'étalement de point n'est pas centrée sur le faisceau, la fonction d'étalement de point comprend donc au moins une fonction dont la valeur maximale n'est pas localisée au centre du faisceau. Préférentiellement, elle est centrée sur le pic de diffusion vers l'arrière. Avantageusement, la fonction d'étalement de point utilise des lois de distribution gamma.
摘要:
The invention discloses a method for calculating the parameters of a resist model of an IC manufacturing process. According to an embodiment of the method of the invention, a function representative of the target design convoluted throughout the whole target design with a kernel function compounded with a deformation function with a shift angle. Advantageously, the deformation function is replaced by its Fourier series development, the order of which is selected so that the product of convolution is invariant through rotations within a tolerance of the corrections to be applied to the target design. Alternatively, the product of convolution may be decomposed into basic kernel functions selected varying by angles determined so that a deformation function for a value of the shift angle can be projected onto a couple of basic kernel functions the angles of which are proximate to the shift angle.
摘要:
According to the invention, an IC manufacturing model is disclosed, wherein input variables and an output variable are measured using a calibration set of patterns. The model can or not include a PSF. The output variable may be a dimensional bias between printed patterns and target patterns or simulated patterns. It can also be a Threshold To Meet Experiments (TTME). The input variables may be defined by a metric which uses kernel functions, preferably with a deformation function which includes a shift angle and a convolution procedure. A functional or associative relationship between the input variables and the output variable is defined. Preferably this definition includes normalization steps and interpolation steps. Advantageously, the interpolation step is of the kriging type. The invention achieves a much more accurate modeling of IC manufacturing, simulation or inspection processes.
摘要:
The invention discloses a method to easily determine the parameters of a second process for manufacturing from the parameters of a first process. Metrics representative of the differences between the two processes are computed from a number of values of the parameters, which can be measured for the two processes on a calibration layout, or which can be determined from pre-existing values for layouts or reference data for the two processes by an interpolation/extrapolation procedure. The number of metrics is selected so that their combination gives a precise representation of the differences between the two processes in all areas of a design. Advantageously, the metrics are calculated as a product of convolution of the target design and a compound of a kernel function and a deformation function.