A method of generating a layout pattern includes determining a first energy density indirectly exposed to a first feature of one or more features of a layout pattern on an energy-sensitive material when the one or more features of the layout pattern on the energy-sensitive material are directly exposed by a charged particle beam. The method also includes adjusting a second energy density exposed the first feature when the first feature is directly exposed by the charged particle beam. A total energy density of the first feature that comprises a sum of the first energy density from the indirect exposure and the second energy density from the direct exposure is maintained at about a threshold energy level to fully expose the first feature in the energy-sensitive material.

Methods for exposing a desired shape in an area on a surface using a charged particle beam system include determining a local pattern density for the area, based on an original set of exposure information. A pre-proximity effect correction (PEC) maximum dose for the local pattern density is determined, based on a pre-determined target post-PEC maximum dose. The pre-PEC maximum dose is calculated near an edge of the desired shape. Methods also include modifying the original set of exposure information with the pre-PEC maximum dose to create a modified set of exposure information.

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 generating a layout pattern includes determining a first energy density indirectly exposed to a first feature of one or more features of a layout pattern on an energy-sensitive material when the one or more features of the layout pattern on the energy-sensitive material are directly exposed by a charged particle beam. The method also includes adjusting a second energy density exposed the first feature when the first feature is directly exposed by the charged particle beam. A total energy density of the first feature that comprises a sum of the first energy density from the indirect exposure and the second energy density from the direct exposure is maintained at about a threshold energy level to fully expose the first feature in the energy-sensitive material.

A charged particle beam writing method includes acquiring a pair of a reference dose and a backscatter coefficient for proximity effect correction using a first settling time, acquiring a first relation between a temperature rise amount and a critical dimension variation amount using a second settling time shorter than the first settling time, the backscatter coefficient and the reference dose acquired, calculating a temperature correction parameter depending on a temperature rise amount, for correcting a dose, by using the first relation, and a second relation on a dose and a pattern critical dimension in a case of using the first settling time, calculating a beam irradiation dose by the reference dose and a dose coefficient obtained from the backscatter coefficient of the pair acquired, and the temperature correction parameter, and writing a pattern with a beam based on the dose calculated using the second settling time.

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.

Methods for exposing a desired shape in an area on a surface using a charged particle beam system include determining a local pattern density for the area of the desired shape based on an original set of exposure information. A backscatter for a sub area is calculated, based on the original set of exposure information. 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 pre-PEC maximum dose is determined for the local pattern density, based on a pre-determined target post-PEC maximum dose. The original set of exposure information is modified with the pre-PEC maximum dose and the increased dosage of the at least one pixel in the sub area to create a modified set of exposure information.

Methods and systems for exposing a desired shape in an area on a surface using a charged particle beam system include determining a local pattern density for the area, based on an original set of exposure information. A pre-proximity effect correction (PEC) maximum dose for the local pattern density is determined, based on a pre-determined target post-PEC maximum dose. The pre-PEC maximum dose may be calculated near an edge of the desired shape. Methods also include modifying the original set of exposure information with the pre-PEC maximum dose to create a modified set of exposure information.

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.