According to one embodiment, a method for displaying an index value in generation of a mask pattern verification model includes: calculating a first index value using a plurality of images; estimating a model on the basis of the first index value and pattern information; calculating a second index value using the model; and displaying at least one of the first index value and the second index value.

According to one embodiment, a method for displaying an index value in generation of a mask pattern verification model includes: calculating a first index value using a plurality of images; estimating a model on the basis of the first index value and pattern information; calculating a second index value using the model; and displaying at least one of the first index value and the second index value.

In some embodiments, techniques are provided for verifying that a fabrication system can fabricate a proposed segmented design. A paintbrush pattern that represents capabilities of the fabrication system is determined. One or more forbidden patterns that the fabrication system is not capable of fabricating are determined based on the paintbrush pattern. The proposed segmented design is then searched for the forbidden patterns. If any forbidden patterns are found, the proposed segmented design is determined to not be fabricable by the fabrication system. If no forbidden patterns are found, then the proposed segmented design is determined to be fabricable by the fabrication system.

In some embodiments, techniques are provided for verifying that a fabrication system can fabricate a proposed segmented design. A paintbrush pattern that represents capabilities of the fabrication system is determined. One or more forbidden patterns that the fabrication system is not capable of fabricating are determined based on the paintbrush pattern. The proposed segmented design is then searched for the forbidden patterns. If any forbidden patterns are found, the proposed segmented design is determined to not be fabricable by the fabrication system. If no forbidden patterns are found, then the proposed segmented design is determined to be fabricable by the fabrication system.

A method for source mask optimization or mask only optimization used to image a pattern onto a substrate. The method includes determining a non-uniform illumination intensity profile for illumination; and determining one or more adjustments for the pattern based on the non-uniform illumination intensity profile until a determination that features patterned onto a substrate substantially match a target design. The non-uniform illumination intensity profile may be determined based on an illumination optical system and projection optics of a lithographic apparatus. In some embodiments, the lithographic apparatus includes a slit, and the non-uniform illumination profile is a through slit non-uniform illumination intensity profile. Determining the one or more adjustments for the pattern may include performing optical proximity correction, for example.

A method for source mask optimization or mask only optimization used to image a pattern onto a substrate. The method includes determining a non-uniform illumination intensity profile for illumination; and determining one or more adjustments for the pattern based on the non-uniform illumination intensity profile until a determination that features patterned onto a substrate substantially match a target design. The non-uniform illumination intensity profile may be determined based on an illumination optical system and projection optics of a lithographic apparatus. In some embodiments, the lithographic apparatus includes a slit, and the non-uniform illumination profile is a through slit non-uniform illumination intensity profile. Determining the one or more adjustments for the pattern may include performing optical proximity correction, for example.

A method of making mask patterns includes the following steps. A first octagon feature is created, wherein the first octagon feature includes first sides, second sides orthogonal to the first sides, and third sides, wherein each of the third sides connects the corresponding first side to the corresponding second side. An optical proximity correction (OPC) process is applied by using a computer to parallel shift the first sides, the second sides and the third sides of the first octagon feature respectively, and thus to create a second octagon feature. The second octagon feature is applied to make a pattern of a photomask. A method of forming a pattern in a layer is also provided, which includes printing a circular pattern on a surface of a layer by using an octagon pattern of a photomask.

A method of making mask patterns includes the following steps. A first octagon feature is created, wherein the first octagon feature includes first sides, second sides orthogonal to the first sides, and third sides, wherein each of the third sides connects the corresponding first side to the corresponding second side. An optical proximity correction (OPC) process is applied by using a computer to parallel shift the first sides, the second sides and the third sides of the first octagon feature respectively, and thus to create a second octagon feature. The second octagon feature is applied to make a pattern of a photomask. A method of forming a pattern in a layer is also provided, which includes printing a circular pattern on a surface of a layer by using an octagon pattern of a photomask.

A method for correcting mask patterns includes providing a target layout, including a plurality of main patterns; dividing the target layout into a plurality of first regions along a first direction; acquiring position information of each first region of the plurality of first regions; acquiring a first model of each first region according to the position information of the first region; acquiring pattern parameters of auxiliary patterns around each main pattern of the first region; and arranging, around each main pattern, the auxiliary patterns of the main pattern according to the pattern parameters of the auxiliary patterns.

A method for correcting mask patterns includes providing a target layout, including a plurality of main patterns; dividing the target layout into a plurality of first regions along a first direction; acquiring position information of each first region of the plurality of first regions; acquiring a first model of each first region according to the position information of the first region; acquiring pattern parameters of auxiliary patterns around each main pattern of the first region; and arranging, around each main pattern, the auxiliary patterns of the main pattern according to the pattern parameters of the auxiliary patterns.