A method for obtaining exposure data may be provided. MTO (Mask Tape Out) design data for a mask pattern may be received. A mask data preparation operation with respect to the MTO design data may be performed to obtain exposure data. Two-dimensional contours of a plurality of types of test patterns in an exposure mask may be extracted through simulation using a mask process model. First critical dimensions may be measured at measurement points of the contour of each of the plurality of types of test patterns by using a metrology algorithm. The first critical dimensions may be averaged to obtain a first average critical dimension for each of the plurality of types of test patterns. Second critical dimensions in consideration of dispersion in each of the plurality of types of test patterns may be measured using an inverse function of a standard normal distribution, and the second critical dimensions may be averaged to obtain a second average critical dimension for each of the plurality of types of test patterns. A mean to target (MTT) value may be calculated as a difference between the second average critical dimension and a target critical dimension for each of the plurality of types of test patterns. Differences between ones of the MTT values may be calculated. When one or more of the differences between the ones of the MTT values may is outside of a tolerance threshold, the exposure data may be corrected.

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.

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.

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 includes generating an electron beam from a radiation source; modifying an energy distribution of the electron beam through a first shaping aperture; and exposing a substrate to portions of the electron beam passing through the first shaping aperture. The first shaping aperture comprises blocking strips with a plurality of slots therebetween, a frame surrounding the blocking strips, and a diagonal support connected to the frame and one of the blocking strips.

A method includes generating an electron beam from a radiation source; modifying an energy distribution of the electron beam through a first shaping aperture; and exposing a substrate to portions of the electron beam passing through the first shaping aperture. The first shaping aperture comprises blocking strips with a plurality of slots therebetween, a frame surrounding the blocking strips, and a diagonal support connected to the frame and one of the blocking strips.

A method for compensating pattern placement errors during writing a pattern on a target in a charged-particle multi-beam exposure apparatus including a layout generated by exposing a plurality of beam field frames using a beam of electrically charged particles, wherein each beam field frame has a respective local pattern density, corresponding to exposure doses imparted to the target when exposing the respective beam field frames. During writing the beam field frames, the positions deviate from respective nominal positions because of build-up effects within said exposure apparatus, depending on the local pattern density evolution during writing the beam field frames. To compensate, a displacement behavior model is employed to predict displacements; a local pattern density evolution is determined, displacements of the beam field frames are predicted based on the local pattern density evolution and the displacement behavior model, and the beam field frames are repositioned accordingly based on the predicted values.

A method for forming a photomask includes receiving a mask substrate including a protecting layer and a shielding layer formed thereon, removing portions of the shielding layer to form a patterned shielding layer, and providing a BSE detector to monitor the removing of the portions of the shielding layer. When a difference in BSE intensities obtained from the BSE detector is greater than approximately 30%, the removing of the portions of the shielding layer is stopped. The BSE intensity in following etching loops becomes stable.

A method for mask data synthesis and mask making includes calibrating an optical proximity correction (OPC) model by adjusting a plurality of parameters including a first parameter and a second parameter, wherein the first parameter indicates a long-range effect caused by an electron-beam lithography tool for making a mask used to manufacture a structure, and the second parameter indicates a geometric feature of a structure or a manufacturing process to make the structure, generating a device layout, calculating a first grid pattern density map of the device layout, generating a long-range correction map, at least based on the calibrated OPC model and the first grid pattern density map of the device layout, and performing an OPC to generate a corrected mask layout, at least based on the generated long-range correction map and the calibrated OPC model.

According to one embodiment, a pattern drawing method includes correcting a drawing parameter for a pattern to be drawn on a resist film on a surface of a substrate. The correction being based on drawing information, height information, and dimensional difference information. The drawing information is design data for drawing the pattern on the resist film by irradiating the resist film with an electron beam. The height information indicates changes in surface height of the substrate. The dimensional difference information includes differences between a dimension of a pattern as indicated in the design data and a dimension of a pattern formed on the substrate by processing the substrate using a resist film patterned according to the drawing information as a mask. The correction of the drawing parameter reduces a dimensional difference between design data and a pattern formed on a target portion on the surface of the substrate.