In a method of manufacturing a photomask, a layout of a circuit mask pattern in a mask region corresponding to a chip region of a substrate is designed. A layout of a monitoring mask pattern representing a critical dimension (CD) of the circuit mask pattern in the mask region is designed. The monitoring mask pattern includes a mask-critical dimension uniformity (CDU) detection pattern configured to detect CDU in mask and a wafer-CDU detection pattern configured to detect CDU in wafer. A first optical proximity correction (OPC) is performed on the mask-CDU detection pattern. A second optical proximity correction is performed on the wafer-CDU detection pattern. A photomask having the circuit mask pattern and the monitoring mask pattern is formed.

A method for exposing a pattern in an area on a surface using a charged particle beam lithography is disclosed and includes inputting an original set of exposure information for the area. The area comprises a plurality of pixels, and the original set of exposure information comprises dosages for the plurality of pixels in the area. A backscatter is calculated for a sub area of the area based on the original set of exposure information. A dosage for at least one pixel in a plurality of pixels in the sub area is increased, in a location where the backscatter of the sub area is below a pre-determined threshold, thereby increasing the backscatter of the sub area. A modified set of exposure information is output, including the increased dosage of the at least one pixel in the sub area.

In a method of manufacturing a photomask, a layout of a circuit mask pattern in a mask region corresponding to a chip region of a substrate is designed. A layout of a monitoring mask pattern representing a critical dimension (CD) of the circuit mask pattern in the mask region is designed. The monitoring mask pattern includes a mask-critical dimension uniformity (CDU) detection pattern configured to detect CDU in mask and a wafer-CDU detection pattern configured to detect CDU in wafer. A first optical proximity correction (OPC) is performed on the mask-CDU detection pattern. A second optical proximity correction is performed on the wafer-CDU detection pattern. A photomask having the circuit mask pattern and the monitoring mask pattern is formed.

A method for exposing a pattern in an area on a surface using a charged particle beam lithography is disclosed and includes inputting an original set of exposure information for the area. A backscatter is calculated for the area of the pattern based on the exposure information. An artificial background dose is determined for the area. The artificial background dose comprises additional exposure information and is combined with the original set of exposure information creating a modified set of exposure information. A system for exposing a pattern in an area on a surface using a charged particle beam lithography is also disclosed.

A method of pattern data preparation includes the following steps. A desired pattern to be formed on a surface of a layer is inputted. A first set of beam shots are determined, and a first calculated pattern on the surface is calculated from the first set of beam shots. The first calculated pattern is rotated, so that a boundary of the desired pattern corresponding to a non-smooth boundary of the first calculated pattern is parallel to a boundary constituted by beam shots. A second set of beam shots are determined to revise the non-smooth boundary of the first calculated pattern, thereby calculating a second calculated pattern being close to the desired pattern on the surface. The present invention also provides a method of forming a pattern in a layer.

In one embodiment, a charged particle beam writing method includes virtually dividing a writing region of the substrate into a plurality of first mesh regions in a first mesh size, calculating an area density of the pattern for each of the plurality of first mesh regions to generate first mesh data, converting a mesh size of the first mesh data into a second mesh size greater than the first mesh size to generate second mesh data, performing a convolution operation between the second mesh data and a proximity effect correction kernel to generate third mesh data, converting a mesh size of the third mesh data into the first mesh size to generate fourth mesh data, performing a convolution operation between the first mesh data and a middle range effect correction kernel to generate fifth mesh data, and adding the fourth mesh data and the fifth mesh data together to calculate an irradiation amount of the charged particle beam for each of the plurality of first mesh regions.

In one embodiment, a charged particle beam writing method includes dividing a figure pattern defined in writing data into a plurality of shot figures, virtually dividing a writing target substrate into a plurality of mesh regions, and calculating a correction irradiation amount to correct proximity effect and middle range effect for each of the mesh regions based on a position of the figure pattern, calculating an irradiation amount for each of the plurality of shot figures using the correction irradiation amount, calculating an insufficient irradiation amount at an edge portion of the shot figure based on the irradiation amount, resizing the shot figure based on the insufficient irradiation amount, and writing the resized shot figure on the writing target substrate using a charged particle beam in the irradiation amount.

Methods include inputting an array of pixels, where each pixel in the array of pixels has a pixel dose. The array of pixels represents dosage on a surface to be exposed with a plurality of patterns, each pattern of the plurality of patterns having an edge. A target bias is input. An edge of a pattern in the plurality of patterns is identified. For each pixel which is in a neighborhood of the identified edge, a calculated pixel dose is calculated such that the identified edge is relocated by the target bias. The array of pixels with the calculated pixel doses is output. Systems for performing the methods are also disclosed.

The present disclosure provides one embodiment of an IC method. First pattern densities (PDs) of a plurality of templates of an IC design layout are received. Then a high PD outlier template and a low PD outlier template from the plurality of templates are identified. The high PD outlier template is split into multiple subsets of template and each subset of template carries a portion of PD of the high PD outlier template. A PD uniformity (PDU) optimization is performed to the low PD outlier template and multiple individual exposure processes are applied by using respective subset of templates.

According to one aspect of the present invention, a charged particle beam writing apparatus includes correction figure data generation circuitry configured to generate pattern data of a correction figure pattern for correcting a figure portion detected, where the pattern data includes dose information to identify a dose of the correction figure pattern; correction figure pattern data conversion circuitry configured to convert the pattern data of the correction figure pattern into correction figure pattern pixel data defining a value corresponding to a dose for the each pixel, based on pixel setting common to that of the writing pattern pixel data; and combined-value pixel data generation circuitry configured to generate, for the each pixel, combined-value pixel data by adding the value defined in the writing pattern pixel data and the value defined in the correction figure pattern pixel data.