Abstract: A method for compensating for lens aberrations, which includes the steps of: (a) defining a cost metric which quantifies an imaging performance of an imaging system, where the cost metric reflects the effects of lens aberrations on the imaging performance; (b) defining a source illumination profile; (c) evaluating the cost metric based on the source illumination profile; (d) modifying the source illumination profile, and re-evaluating the cost metric based on the modified source illumination profile; and (e) repeating step (d) until the cost metric is minimized. The source illumination profile corresponding to the minimized cost metric represents the optimal illumination for the imaging device.

Abstract: A photolithography mask for optically transferring a pattern formed in the mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, and at least one non-resolvable optical proximity correction feature, where the non-resolvable optical proximity correction feature is a phase-edge.

Abstract: A method for optically transferring a lithographic pattern corresponding to an integrated circuit utilizing a high transmission attenuated phase-shift mask onto a semiconductor substrate by use of an optical exposure tool. The method comprising the steps of generating a diffraction pattern corresponding to the lithographic pattern, where the diffraction pattern indicates a plurality of spatial frequency components corresponding to the lithographic pattern; determining which of the spatial frequency components need to be captured by a lens in the optical exposure tool in order to accurately reproduce the lithographic pattern; determining a set of illumination conditions required for the optical exposure tool to capture the spatial frequency components necessary for accurately reproducing the lithographic pattern; and illuminating the high transmission attenuated phase-shift mask with this set of illumination conditions.

Abstract: A photolithography mask for optically transferring a pattern formed in the mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, and at least one non-resolvable optical proximity correction feature disposed between two of the resolvable features to be printed, where the non-resolvable optical proximity correction feature has a transmission coefficient in the range of greater than 0% to less than 100%.

Abstract: A method of generating a mask for use in printing a target pattern on a substrate. The method includes the steps of: (a) determining a target pattern representing a circuit design to be printed on a substrate; (b) generating a first pattern by scaling the target pattern by a factor of 0.5; and (c) generating a second pattern by performing a Boolean operation which combines the target pattern and the first pattern. The second pattern is then utilized to print the target pattern on the substrate.

Abstract: A method of printing a gate pattern on a substrate comprising the steps of: identifying at least one area in the pattern in which one of the gate features overlays one of the active regions; reducing a width dimension of the one of the gate features at the location which the one of the gate features overlays the one of the active regions; extracting the gate features from the pattern; decomposing the gate features into a vertical component mask and a horizontal component mask; and illuminating the vertical component mask and the horizontal component mask utilizing dipole illumination.

Abstract: A photolithography mask for optically transferring a pattern formed in said mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, where each of the plurality of resolvable features has a longitudinal axis extending in a first direction; and a pair of non-resolvable optical proximity correction features disposed between two of the plurality of resolvable features, where the pair of non-resolvable optical proximity correction features has a longitudinal axis extending in a second direction, wherein the first direction of the longitudinal axis of the plurality of resolvable features is orthogonal to the second direction of the longitudinal axis of the pair of non-resolvable optical proximity correction features.

Abstract: A method of transferring a lithographic pattern onto a substrate by use of a lithographic apparatus. The method includes the steps of: (1) defining features to be printed on the substrate; (2) determining which of the features require assist features to be disposed adjacent thereto in order for the features to be printed within defined resolution limits; (3) generating a mask containing the features to be printed and the assist features; (4) performing a first illumination process so as to print the features on the substrate, the first illumination process resulting in the partial printing of the assist features on the substrate; and (5) performing a second illumination process so as to reduce the amount of the assist features printed on the substrate; the second illumination process entails the step of performing a quadrapole illumination.

Abstract: A method of generating a mask of use in printing a target pattern on a substrate. The method includes the steps of (a) determining a maximum width of features to be imaged on the substrate utilizing phase-structures formed in the mask; (b) identifying all features contained in the target pattern having a width which is equal to or less than the maximum width; (c) extracting all features having a width which is equal to or less than the maximum width from the target pattern; (d) forming phase-structures in the mask corresponding to all features identified in step (b); and (e) forming opaque structures in the mask for all features remaining in target pattern after performing step (c).

Abstract: A method of forming a hybrid mask for optically transferring a lithographic pattern corresponding to an integrated circuit from the mask onto a semiconductor substrate by use of an optical exposure tool. The method includes the steps of forming at least one non-critical feature on the mask utilizing one of a low-transmission phase-shift mask (pattern) and a non-phase shifting mask (pattern), and forming at least one critical feature on the mask utilizing a high-transmission phase-shift mask (pattern).

Abstract: Optical proximity effects (OPEs) are a well-known phenomenon in photolithography. OPEs result from the structural interaction between the main feature and neighboring features. It has been determined by the present inventors that such structural interactions not only affect the critical dimension of the main feature at the image plane, but also the process latitude of the main feature. Moreover, it has been determined that the variation of the critical dimension as well as the process latitude of the main feature is a direct consequence of light field interference between the main feature and the neighboring features. Depending on the phase of the field produced by the neighboring features, the main feature critical dimension and process latitude can be improved by constructive light field interference, or degraded by destructive light field interference. The phase of the field produced by the neighboring features is dependent on the pitch as well as the illumination angle.

Abstract: A method of detecting aberrations associated with a projection lens utilized in an optical lithography system. The method includes the steps of forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of non-resolvable features disposed on the mask, where the plurality of non-resolvable features are arranged so as to form a predetermined pattern on the substrate, exposing the mask using an optical exposure tool so as to print the mask on the substrate, and analyzing the position of the predetermined pattern formed on the substrate and the position of the plurality of non-resolvable features disposed on the mask so as to determine if there is an aberration. If the position of the predetermined pattern formed on the substrate differs from an expected position, which is determined from the position of the plurality of non-resolvable features, this shift from the expected position indicates the presence of an aberration.

Abstract: A method of detecting aberrations associated with a projection lens utilized in an optical lithography system. The method includes the steps of forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of non-resolvable features disposed on the mask, where the plurality of non-resolvable features are arranged so as to form a predetermined pattern on the substrate, exposing the mask using an optical exposure tool so as to print the mask on the substrate, and analyzing the position of the predetermined pattern formed on the substrate and the position of the plurality of non-resolvable features disposed on the mask so as to determine if there is an aberration. If the position of the predetermined pattern formed on the substrate differs from an expected position, which is determined from the position of the plurality of non-resolvable features, this shift from the expected position indicates the presence of an aberration.

Abstract: The present invention provides a method and apparatus for simulating an aerial image projected from an optical system, wherein the optical system includes a pupil and a mask. In general, the method comprises the steps of obtaining parameters for the optical system, calculating a kernel based on an orthogonal pupil projection of the parameters of the optical system onto a basis set, obtaining parameters of the mask, calculating a vector based on an orthogonal mask projection of the parameters of the mask onto a basis set, calculating a field intensity distribution using the kernel and the vector, and obtaining aerial image data from the field intensity distribution.

Abstract: A method of generating complementary masks for use in a multiple-exposure lithographic imaging process. The method includes the steps of identifying “horizontal” critical features and “vertical” critical features from a plurality of features forming a layout; identifying interconnection areas which are areas in which one of the horizontal critical features or the vertical critical features contacts another feature of the layout; defining a set of primary parameters on the basis of the proximity of the plurality of features relative to one another; and generating an edge modification plan for each interconnection area based on the primary parameters. A horizontal mask pattern is then generated by compiling the horizontal critical features, a first shield plan for the vertical critical features and the interconnection areas containing a horizontal critical feature modified by the edge modification plan.

Abstract: Optical proximity effects (OPEs) are a well-known phenomenon in photolithography. OPEs result from the structural interaction between the main feature and neighboring features. It has been determined by the present inventors that such structural interactions not only affect the critical dimension of the main feature at the image plane, but also the process latitude of the main feature. Moreover, it has been determined that the variation of the critical dimension as well as the process latitude of the main feature is a direct consequence of light field interference between the main feature and the neighboring features. Depending on the phase of the field produced by the neighboring features, the main feature critical dimension and process latitude can be improved by constructive light field interference, or degraded by destructive light field interference. The phase of the field produced by the neighboring features is dependent on the pitch as well as the illumination angle.