Abstract: A method is provided 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. A reference physical model of the reference process is determined. A sizing correction to be applied to the edges of the design produced by the reference process is calculated.

Abstract: A method for projecting an electron beam onto a target includes correction of the scattering effects of the electrons in the target. This correction is made possible by a calculation step of a point spread function having a radial variation according to a piecewise polynomial function.

Abstract: A method of geometry corrections to properly transfer semiconductor designs on a wafer or a mask in nanometer scale processes is provided. In contrast with some prior art techniques, geometry corrections and possibly dose corrections are applied before fracturing. Unlike edge based corrections, where the edges are displaced in parallel, the displacements applied to generated geometry corrections do not preserve parallelism of the edges, which is specifically well suited for free form designs. A seed design is generated from the target design. Vertices connecting segments are placed along the seed design contour. Correction sites are placed on the segments. Displacement vectors are applied to the vertices. A simulated contour is generated and compared to the contour of the target design. The process is iterated until a match criteria between simulated and target design (or another stop criteria) is reached.

Abstract: A method for transferring a pattern onto a substrate by direct writing by means of a particle or photon beam comprises: a step of producing a dose map, associating a dose to elementary shapes of the pattern; and a step of exposing the substrate according to the pattern with a spatially-dependent emitted dose depending on the dose map; wherein the step of producing a dose map includes: computing at least first and second metrics of the pattern for each of the elementary shapes, the first metric representative of features of the pattern within a first range from the elementary shape and the second metric representative of features of the pattern within a second range, larger than the first range, from the elementary shape; and determining the emitted dose associated to each of the elementary shapes of the pattern as a function of the metrics. A computer program product is provided for carrying out such a method or at least the step of producing a dose map.

Abstract: A method for calculating the parameters of a resist model of an IC manufacturing process is provided. Accordingly, 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. 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.

Abstract: 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 cannot 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. 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.

Abstract: A method to easily determine parameters of a second process for manufacturing from parameters of a first process is provided. Metrics representative of differences between the first process and the second process are computed from a number of values of the parameters, which can be measured for the first process and the second process on a calibration layout, or which can be determined from pre-existing values for layouts or reference data for the first process and the second process by an interpolation/extrapolation procedure. A set of metrics are selected so that their combination gives a precise representation of the differences between the first process and the second process in all areas of a target 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.

Abstract: A method of generating data relative to the writing of a pattern by electronic radiation initially includes the provision of a pattern to be formed which form the work pattern with a single external envelope. The work pattern is broken down into a set of elementary outlines, each including a single external envelope. A set of insolation conditions is defined to model each elementary outline. An irradiated simulation pattern is calculated from the sets of insolation conditions associated with the sets of elementary outlines. The simulation pattern is compared with the pattern to be formed. If the simulation pattern is not representative of the pattern to be formed, shift vectors are calculated. The shift vectors are representative of different intervals existing between the two patterns. The external envelope of the pattern to be formed is modified from displacement vectors determined from the shift vectors. A new iteration is carried out.

Abstract: A method for projecting an electron beam used notably in lithography by direct or indirect writing as well as in electron microscopy, is provided. Notably for critical dimensions or resolutions of less than 50 nm, the proximity effects created by the forward and backward scattering of the electrons of the beam in interaction with the target must be corrected. This is traditionally done using the convolution of a point spread function with the geometry of the target. In the prior art, said point spread function uses Gaussian distribution laws. At least one of the components of the point spread function is a linear combination of Voigt functions and/or of functions approximating Voigt functions, such as the Pearson VII functions. In certain embodiments, some of the functions are centered on the backward scattering peaks of the radiation.

Abstract: The invention discloses a computer implemented method of fracturing a surface into elementary features wherein the desired pattern has a rectilinear or curvilinear form. Depending upon the desired pattern, a first fracturing will be performed of a non-overlapping or an overlapping type. If the desired pattern is resolution critical, it will be advantageous to perform a second fracturing step using eRIFs. These eRIFs will be positioned either on the edges or on the medial axis or skeleton of the desired pattern. The invention further discloses method steps to define the position and shape of the elementary features used for the first and second fracturing steps.

Abstract: A computer implemented method of fracturing free form target design into elementary shots for defined roughness of the contour comprises determining a first set of shots which pave the target design and determining a second set of shots to fill the gaps. The dose levels of overlapping shots in the first or second sets of shots are determined so the compounded dose is adequate to the resist threshold, considering the proximity effect of the actual imprint of shots on the insulated target. A dose geometry modulation is applied and rounded shot prints are produced by shots not circular that may overlap. The degree of overlap is determined as a function of desired optimization of fit criteria between a printed contour and the contour of the desired pattern. Placements and dimensions of the shots are determined by a plurality of fit criteria between printed contour and contour of the desired pattern.

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 discretization error correction is made by dithering.

Abstract: This method for estimating patterns (M?PF,D?PF) to be printed by means of electron-beam lithography, comprises the following steps: printing (100), in a resin, a set of calibration patterns (MCF, DCF); measuring (120) characteristic dimensions (CD) of this set; supplying an estimation (140) of the point spread function (PSF) based on the characteristic dimensions (CD) measured; estimating (160) the patterns (M?PF,D?PF) to be printed by convoluting the point spread function (PSF) supplied with an initial value of the patterns (MPF,DPF). Furthermore, each calibration pattern printed includes a central zone exposed to the electron beam and a plurality of surrounding concentric zones with rotational symmetry. The characteristic dimensions measured are characteristic dimensions (CD) of the central zones of the patterns.

Abstract: A method for projecting an electron beam onto a target includes correction of the scattering effects of the electrons in the target. This correction is made possible by a calculation step of a point spread function having a radial variation according to a piecewise polynomial function.

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.

Abstract: A method of lithography by radiation having critical dimensions of the order of some ten nanometers makes it possible to carry out the correction of the proximity effects by joint optimization of the dose modulation and geometric corrections. Accordingly, a deconvolution of the pattern to be etched is carried out by an iterative procedure modeling the interactions of the radiation with the resined support by a joint probability distribution. Advantageously, when the support exposure tool is of formed-beam type, the pattern to be etched is split into contrasted levels and then the deconvolved image is vectorized and fractured before carrying out the exposure step. In an advantageous embodiment, the method is applied to at least two character cells which are exposed in a multi-pass cells projection method.

Abstract: The invention discloses a computer implemented method of fracturing a surface into elementary features wherein the desired pattern has a rectilinear or curvilinear form. Depending upon the desired pattern, a first fracturing will be performed of a non-overlapping or an overlapping type. If the desired pattern is resolution critical, it will be advantageous to perform a second fracturing step using eRIFs. These eRIFs will be positioned either on the edges or on the medial axis or skeleton of the desired pattern. The invention further discloses method steps to define the position and shape of the elementary features used for the first and second fracturing steps.

Abstract: A method of lithography by radiation having critical dimensions of the order of some ten nanometers makes it possible to carry out the correction of the proximity effects by joint optimization of the dose modulation and geometric corrections. Accordingly, a deconvolution of the pattern to be etched is carried out by an iterative procedure modeling the interactions of the radiation with the resined support by a joint probability distribution. Advantageously, when the support exposure tool is of formed-beam type, the pattern to be etched is split into contrasted levels and then the deconvolved image is vectorized and fractured before carrying out the exposure step. In an advantageous embodiment, the method is applied to at least two character cells which are exposed in a multi-pass cells projection method.

Abstract: The invention discloses a computer implemented method of fracturing a surface into elementary features wherein the desired pattern has a rectilinear or curvilinear form. Depending upon the desired pattern, a first fracturing will be performed of a non-overlapping or an overlapping type. If the desired pattern is resolution critical, it will be advantageous to perform a second fracturing step using eRIFs. These eRIFs will be positioned either on the edges or on the medial axis or skeleton of the desired pattern. The invention further discloses method steps to define the position and shape of the elementary features used for the first and second fracturing steps.

Abstract: This method for estimating patterns (M?PF,D?PF) to be printed by means of electron-beam lithography, comprises the following steps: printing (100), in a resin, a set of calibration patterns (MCF, DCF); measuring (120) characteristic dimensions (CD) of this set; supplying an estimation (140) of the point spread function (PSF) based on the characteristic dimensions (CD) measured; estimating (160) the patterns (M?PF,D?PF) to be printed by convoluting the point spread function (PSF) supplied with an initial value of the patterns (MPF,DPF). Furthermore, each calibration pattern printed includes a central zone exposed to the electron beam and a plurality of surrounding concentric zones with rotational symmetry. The characteristic dimensions measured are characteristic dimensions (CD) of the central zones of the patterns.