A process proximity correction method is performed by a process proximity correction computing device which performs a process proximity correction (PPC) through at least one of a plurality of processors. The process proximity correction method includes: converting a target layout including a plurality of patterns into an image, zooming-in or zooming-out the image at a plurality of magnifications to generate a plurality of input channels, receiving the plurality of input channels and performing machine learning to predict an after-cleaning image (ACI), comparing the predicted after-cleaning image with a target value to generate an after-cleaning image error, and adjusting the target layout on the basis of the after-cleaning image error.

A process proximity correction method is performed by a process proximity correction computing device which performs a process proximity correction (PPC) through at least one of a plurality of processors. The process proximity correction method includes: converting a target layout including a plurality of patterns into an image, zooming-in or zooming-out the image at a plurality of magnifications to generate a plurality of input channels, receiving the plurality of input channels and performing machine learning to predict an after-cleaning image (ACI), comparing the predicted after-cleaning image with a target value to generate an after-cleaning image error, and adjusting the target layout on the basis of the after-cleaning image error.

A mask for extreme ultraviolet (EUV) lithography includes a multilayer (ML) stack including alternating metal and semiconductor layers disposed over a first surface of a mask substrate, a capping layer disposed over the ML stack, and an absorber layer disposed over the capping layer. An image pattern is formed in the absorber layer. A border layer surrounding the image pattern is disposed over the absorber layer.

A mask for extreme ultraviolet (EUV) lithography includes a multilayer (ML) stack including alternating metal and semiconductor layers disposed over a first surface of a mask substrate, a capping layer disposed over the ML stack, and an absorber layer disposed over the capping layer. An image pattern is formed in the absorber layer. A border layer surrounding the image pattern is disposed over the absorber layer.

A three-dimensional mask model that provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image.

In a method of manufacturing a photo mask for lithography, circuit pattern data are acquired. A pattern density, which is a total pattern area per predetermined area, is calculated from the circuit pattern data. Dummy pattern data for areas having pattern density less than a threshold density are generated. Mask drawing data is generated from the circuit pattern data and the dummy pattern data. By using an electron beam from an electron beam lithography apparatus, patterns are drawn according to the mask drawing data on a resist layer formed on a mask blank substrate. The drawn resist layer is developed using a developing solution. Dummy patterns included in the dummy pattern data are not printed as a photo mask pattern when the resist layer is exposed with the electron beam and is developed.

A method of making a semiconductor device includes forming at least one fiducial mark on a photomask outside of a pattern region of the photomask, and the at least one fiducial mark includes identifying information for the photomask. The method includes defining a pattern including a plurality of sub-patterns on the photomask in the pattern region based on the identifying information. The defining of the pattern includes defining a first sub-pattern of the plurality of sub-patterns having a first spacing from a second sub-pattern of the plurality of sub-patterns, wherein the first spacing is different from a second spacing between the second sub-pattern and a third sub-pattern of the plurality of sub-patterns, or rotating the first sub-pattern about an axis perpendicular to a top surface of the photomask relative to the second sub-pattern. The method includes transferring the pattern from the photomask to a wafer.

A method of fabricating a circuit element, such as a quantum computing circuit element, including obtaining a lithography mask write file that includes mask information characterizing one or more mask features, obtaining a uniformity function that is configured to modify the mask information to compensate for a non-uniform deposition process, applying the uniformity function to the lithography mask write to obtain a modified lithography mask write file, and performing lithography as directed by the modified lithography mask write file.

A method of fabricating a circuit element, such as a quantum computing circuit element, including obtaining a lithography mask write file that includes mask information characterizing one or more mask features, obtaining a uniformity function that is configured to modify the mask information to compensate for a non-uniform deposition process, applying the uniformity function to the lithography mask write to obtain a modified lithography mask write file, and performing lithography as directed by the modified lithography mask write file.

A mask for extreme ultraviolet (EUV) lithography includes a multilayer (ML) stack including alternating metal and semiconductor layers disposed over a first surface of a mask substrate, a capping layer disposed over the ML stack, and an absorber layer disposed over the capping layer. An image pattern is formed in the absorber layer. A border layer surrounding the image pattern is disposed over the absorber layer.