An apparatus for analyzing and/or processing a sample with a particle beam, comprising: a sample stage for holding the sample; a providing unit for providing the particle beam comprising: an opening for guiding the particle beam to a processing position on the sample; and a shielding element for shielding an electric field generated by charges accumulated on the sample; wherein the shielding element covers the opening, is embodied in sheetlike fashion and comprises an electrically conductive material; wherein the shielding element comprises a convex section, this section being convex in relation to the sample stage; and wherein the convex section has a through opening for the particle beam to pass through to the sample.

Methods for reticle enhancement technology (RET) for use with variable shaped beam (VSB) lithography include inputting a desired pattern to be formed on a substrate; determining an initial mask pattern from the desired pattern for the substrate; optimizing the initial mask pattern for wafer quality using a VSB exposure system; and outputting the optimized mask pattern. Methods for fracturing a pattern to be exposed on a surface using VSB lithography include inputting an initial pattern; overlaying the initial pattern with a two-dimensional grid, wherein an initial set of VSB shots are formed by the union of the initial pattern with locations on the grid; merging two or more adjacent shots in the initial set of VSB shots to create a larger shot in a modified set of VSB shots; and outputting the modified set of VSB shots.

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 difference between a calculated amount of drift and an actual amount of drift is reduced. According to one aspect of the present invention, a charged particle beam writing apparatus includes a deflector adjusting an irradiation position of the charged particle beam with respect to a substrate placed on a stage, a shot data generator generating shot data from writing data, the shot data including a shot position and beam ON and OFF times for each shot, a drift corrector referring to a plurality of pieces of the generated shot data, calculating an amount of drift of the irradiation position of the charged particle beam with which the substrate is irradiated, and generating correction information for correcting an irradiation position deviation based on the amount of drift, a deflection controller controlling a deflection amount achieved by the deflector based on the shot data and the correction information, and a dummy irradiation instructor instructing execution of dummy irradiation in a writing process to irradiate with the charged particle beam in a predetermined irradiation amount at a position different from the substrate on the stage.

The purpose of the present invention is to correct a beam irradiation position shift caused by charging phenomena with high accuracy. A charged particle beam writing method includes virtually dividing a writing region of the substrate so as to have a predetermined mesh size and calculating a pattern density distribution representing an arrangement ratio of the pattern for each mesh region, calculating a dose distribution using the pattern density distribution, calculating an irradiation amount distribution using the pattern density distribution and the dose distribution, calculating a fogging charged particle amount distribution, calculating a charge amount distribution due to direct charge and a charge amount distribution due to fogging charge, calculating a position shift of a writing position based on the charge amount distribution due to direct charge and the charge amount distribution due to fogging charge, correcting an irradiation position using the position shift, and irradiating the corrected irradiation position with the charged particle beam with which a potential of a surface of the substrate becomes higher than a potential of a bottom surface of ae potential regulation member.

An amount of charge of a substrate is promptly and accurately calculated. A charged particle beam writing method includes a step (S100) for virtually dividing a writing region of the writing target substrate in a mesh-like manner and calculating a pattern density representing an arrangement ratio of the pattern for each mesh region, a step (S102) for calculating a dose for each mesh region using the pattern density, a step (S104) for calculating a charge amount based on a film thickness of the resist film formed on the substrate and the calculated dose by using a predetermined function for charge amount calculation, the function using, as variables, the film thickness of the resist film and the dose, a step (S106) for calculating a position shift amount of a writing position from the calculated charge amount, and a step (S108) for correcting an irradiation position of the charged particle beam using the position shift amount.

Methods for reticle enhancement technology (RET) for use with variable shaped beam (VSB) lithography include inputting a desired pattern to be formed on a substrate; determining an initial mask pattern from the desired pattern for the substrate; optimizing the initial mask pattern for wafer quality using a VSB exposure system; and outputting the optimized mask pattern. Methods for fracturing a pattern to be exposed on a surface using VSB lithography include inputting an initial pattern; overlaying the initial pattern with a two-dimensional grid, wherein an initial set of VSB shots are formed by the union of the initial pattern with locations on the grid; merging two or more adjacent shots in the initial set of VSB shots to create a larger shot in a modified set of VSB shots; and outputting the modified set of VSB shots.

Methods for reticle enhancement technology (RET) for use with variable shaped beam (VSB) lithography include inputting a desired pattern to be formed on a substrate; determining an initial mask pattern from the desired pattern for the substrate; optimizing the initial mask pattern for wafer quality using a VSB exposure system; and outputting the optimized mask pattern. Methods for fracturing a pattern to be exposed on a surface using VSB lithography include inputting an initial pattern; overlaying the initial pattern with a two-dimensional grid, wherein an initial set of VSB shots are formed by the union of the initial pattern with locations on the grid; merging two or more adjacent shots in the initial set of VSB shots to create a larger shot in a modified set of VSB shots; and outputting the modified set of VSB shots.

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 one embodiment, a charged particle beam writing apparatus includes a positioning deflector adjusting an irradiation position of a charged particle beam radiated to a substrate which is a writing target, a fixed deflector which is disposed downstream of the positioning deflector in a traveling direction of the charged particle beam, and in which an amount of deflection is fixed, a focus correction lens performing focus correction on the charged particle beam according to a surface height of the substrate, and an object lens focusing the charged particle beam.