JP2013165121A - Drawing device, generating method, program and method for manufacturing article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drawing device advantageous to drawing of a target pattern.SOLUTION: A drawing device for drawing a pattern on a substrate by using a charged particle beam includes a generating unit for generating drawing data, and a charged particle optical system for generating the charged particle beam on the basis of the drawing data generated in the generating unit. The generating unit sets a plurality of pixels corresponding to a target pattern having a width, and on the basis of an intensity distribution of the charged particle beam obtained on the substrate when applying to the plurality of pixels the charged particle beam having preset intensity in which among the plurality of pixels there is a difference between pixels corresponding to ends of the target pattern and pixels other than the pixels, adjusts the preset distribution so as to obtain a distribution intensity corresponding to the width on the substrate, to thereby generate the drawing data.

Description

  The present invention relates to a drawing apparatus that performs drawing on a substrate with a charged particle beam.

  2. Description of the Related Art There is known a charged particle beam drawing apparatus that draws (transfers) a pattern on a substrate by deflecting (raster scanning) the charged particle beam on the substrate. For example, when drawing an isolated pattern with a line width of 48 nm using such a charged particle beam drawing apparatus, the drawing region on the substrate is divided into a plurality of pixels (pixel size = 16 nm) as shown in FIG. To divide. Then, while deflecting the charged particle beam in the X-axis direction by the deflector, using the blanker, the charged particle beam is irradiated (ON) in the pixel corresponding to the pattern portion, and the charged particle beam is blocked in the other pixels ( OFF). When the deflection of the charged particle beam in the X-axis direction is completed, the charged particle beam is stepped in the Y-axis direction. As described above, the charged particle beam drawing apparatus draws a pattern on the substrate by controlling ON / OFF of the charged particle beam while repeating the deflection of the charged particle beam in the X direction and the step in the Y axis direction. . A technique related to ON / OFF control of a charged particle beam in each pixel has been proposed (see Patent Document 1).

JP 2003-297732 A

  However, in recent years, since the minimum line width of a pattern to be drawn by a charged particle beam drawing apparatus has become smaller, it has become difficult to satisfy the required pattern drawing accuracy in the prior art.

  For example, consider a case where a drawing region on a substrate is divided into pixels having a pixel size of 11 nm and an isolated pattern having a line width of 22 nm is drawn. At this time, as shown in FIG. 17, when an isolated pattern is drawn with two pixels (that is, the isolated pattern is arranged on a grid defining the pixels), each of the two pixels is irradiated. Irradiation amount (dose amount) of charged particle beams becomes equal. On the other hand, as shown in FIG. 18, the isolated pattern is not arranged on the grid, and the isolated pattern may be drawn at a position equal to or smaller than the pixel size (that is, with three pixels). Hereinafter, the position between the pixel centers is referred to as a sub-pixel position.

  In FIG. 18, attention is paid to one row Y0 orthogonal to the Y axis. The area ratio occupied by the pattern in the pixel PL where the left edge of the pattern is located is α, and the area ratio occupied by the pattern in the pixel PR where the right edge of the pattern is located is β. FIG. 19 shows an irradiation amount (here, “1”) set for each pixel and the intensity (intensity) of the charged particle beam on the substrate when an isolated pattern is drawn with two pixels (FIG. 17). It is a figure which shows the relationship with distribution. FIG. 20 is a diagram showing the relationship between the dose set for each pixel and the intensity (intensity distribution) of the charged particle beam on the substrate when an isolated pattern is drawn with three pixels (FIG. 18). . As shown in FIG. 20, with respect to the dose 1 set to the pixel PM, the dose of the pixel PL is set to α, and the dose of the pixel PR is set to β.

  In FIG. 19, IL and IR are intensity distributions formed on the substrate when each of the pixels PL and RL is irradiated with a charged particle beam (irradiation amount 1). A profile obtained by integrating the intensity distribution IL and the intensity distribution IR is defined as I. Profile I corresponds to an integral value of the intensity of the charged particle beam irradiated to each pixel. The exposure threshold Th is the intensity level of the charged particle beam that the resist sensitizes, and is a value determined in advance from the sensitivity characteristics of the resist. Based on the exposure threshold Th, the irradiation amount of the charged particle beam is adjusted so that the pattern is drawn with a desired line width. The sensitivity characteristic of the resist shows a non-linear characteristic in the vicinity of the exposure threshold Th. Here, the line width (shape) of the pattern drawn on the substrate is simply determined only by the exposure threshold Th. Shall. Accordingly, the difference between the left edge and the right edge from the left edge and the right edge, which are the intersections of the profile I and the exposure threshold Th, is the pattern line width CD, and the midpoint between the left edge and the right edge is the pattern. The position (center position) Pos can be obtained.

  Each of FIGS. 21A and 21B shows the line width of a pattern at an arbitrary subpixel position when the pixel size is 11 nm and the half-value width of the charged particle beam is 25 nm with respect to an isolated pattern having a line width of 22 nm. It is a figure which shows a position error. Referring to FIGS. 21A and 21B, depending on the position of an isolated pattern having a pixel size or less, an error of 0.9 nm at maximum with respect to the line width of the pattern and an error of 0.67 nm at maximum with respect to the position error of the pattern. You can see that it has occurred.

  The present invention has been made in view of the above-described problems of the related art, and an object of the present invention is to provide a drawing apparatus that is advantageous for drawing a target pattern.

  In order to achieve the above object, a drawing apparatus according to one aspect of the present invention is a drawing apparatus that performs drawing on a substrate with a charged particle beam, the generation unit generating drawing data, and the generation unit A charged particle optical system that generates the charged particle beam based on drawing data, and the generation unit sets a plurality of pixels corresponding to a target pattern having a width, and the target among the plurality of pixels Based on the intensity distribution of the charged particle beam obtained on the substrate when a charged particle beam having a preset intensity different between the pixel corresponding to the edge of the pattern and the other pixels is applied to the plurality of pixels. The drawing data is generated by adjusting the preset intensity distribution so that an intensity distribution corresponding to the width is obtained on the substrate.

  Further objects and other aspects of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the drawing apparatus advantageous for drawing of a target pattern can be provided, for example.

It is a figure which shows the structure of the drawing apparatus as 1 side surface of this invention. It is a figure which shows the structure of the control system of the drawing apparatus shown in FIG. It is a figure for demonstrating the drawing process of the drawing apparatus shown in FIG. It is a flowchart for demonstrating the determination of the auxiliary pattern added to the both ends of a target pattern. It is a figure for demonstrating S102, S106, and S108 shown in FIG. It is a figure which shows the position (position error) of the position of the left edge and the right edge with respect to the position below a pixel size, and the position of the left edge and the right edge, and an ideal position. It is a figure which shows the line | wire width and position error in the position below the pixel size of the pattern drawn on a board | substrate, when the fixed component (gamma) of an auxiliary pattern is 5 to 35%. It is the figure which showed each of the line | wire width error and position error of the pattern shown in FIG. 7 by the range for every ratio of the fixed component of an auxiliary pattern. It is the figure which showed each of the line | wire width error and position error of the pattern shown in FIG. 7 by the range for every ratio of the fixed component of an auxiliary pattern. It is a flowchart for demonstrating the determination of the auxiliary pattern added to the both ends of a target pattern. It is a figure which shows the line | wire width error and position error with respect to the ratio of the several fixed component added as an auxiliary pattern with respect to each of several charged particle beams from which a diameter differs. It is a flowchart for demonstrating determination of the magnification used when adjusting the intensity | strength of the charged particle beam of each pixel (S106). It is a figure which shows the result of having calculated the line width of the pattern in a sub pixel position with respect to the profile produced | generated by S304 shown in FIG. It is a figure for demonstrating the problem which arises when the auxiliary | assistant pattern of a fixed component is not added to the both ends of a target pattern. It is a figure for demonstrating the effect at the time of adding the auxiliary pattern of a fixed component to the both ends of a target pattern. It is a figure for demonstrating the drawing process of the pattern by a drawing apparatus. It is a figure for demonstrating the case where an isolated pattern is drawn with two pixels in a drawing apparatus. It is a figure for demonstrating the case where an isolated pattern is drawn with three pixels in a drawing apparatus. When drawing an isolated pattern with two pixels, it is a figure which shows the relationship between the irradiation amount set to each pixel, and the intensity | strength (intensity distribution) of the charged particle beam on a board | substrate. When drawing an isolated pattern with three pixels, it is a figure which shows the relationship between the irradiation amount set to each pixel, and the intensity | strength (intensity distribution) of the charged particle beam on a board | substrate. It is a figure which shows the line | wire width and position error of the pattern in arbitrary sub pixel positions when pixel size is 11 nm and the half value width of a charged particle beam is 25 nm with respect to an isolated pattern with a line width of 22 nm.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  FIG. 1 is a diagram showing a configuration of a drawing apparatus 100 as one aspect of the present invention. The drawing apparatus 100 is a lithography apparatus that draws a pattern on a substrate using a charged particle beam (electron beam). As will be described later, the drawing apparatus 100 includes a beam shaping optical system 2, a collimator lens 4, an aperture array 5, an electrostatic lens array 6, and a blanker array 7 as charged particle optical systems that generate charged particle beams based on drawing data. And a reduction electron optical system 8. The drawing apparatus 100 may be a single charged particle beam drawing apparatus (drawing apparatus that draws with one charged particle beam), or a multi charged particle beam drawing apparatus (drawing with a plurality of charged particle beams). Drawing apparatus).

  In FIG. 1, the charged particle beam emitted from the electron source 1 forms an image SI of the electron source 1 via the beam shaping optical system 2. The charged particle beam from the image SI becomes a substantially parallel charged particle beam via the collimator lens 4 and illuminates the aperture array 5.

  The aperture array 5 has a plurality of openings and divides the charged particle beam from the electron source 1 into a plurality of charged particle beams. The plurality of charged particle beams divided by the aperture array 5 form an intermediate image of the image SI through the electrostatic lens array 6 including a plurality of electrostatic lenses. A blanker array 7 including a plurality of blankers (for example, electrostatic deflectors) is disposed at a position (intermediate image plane) where an intermediate image of the image SI is formed.

  A reduction electron optical system 8 composed of two stages of magnetic tablet lenses 81 and 82 is disposed downstream of the intermediate image plane, and a plurality of intermediate images are projected onto the substrate 9. At this time, since the charged particle beam deflected by the blanker array 7 is blocked by the blanking aperture BA, the substrate 9 is not irradiated. Further, the charged particle beam that is not deflected by the blanker array 7 is not blocked by the blanking aperture BA, and is thus irradiated onto the substrate 9.

  The magnetic tablet lens 82 is provided with a deflector 10 for deflecting a plurality of charged particle beams simultaneously to a desired position (X direction or Y direction) and a focus coil 12 for simultaneously adjusting the focus of the plurality of charged particle beams. ing. The substrate stage 13 is a stage that holds and moves the substrate 9. In the present embodiment, the substrate stage 13 is movable in the X direction and the Y direction orthogonal to the optical axis. On the substrate stage 13, an electrostatic chuck 15 and a semiconductor detector 14 for adsorbing (fixing) the substrate 9 are arranged. The semiconductor detector 14 is a detector for detecting the shape (diameter) of a charged particle beam, and has, for example, a knife edge on the incident side of the charged particle beam.

  FIG. 2 is a diagram illustrating a configuration of the control system CL of the drawing apparatus 100. The control system CL includes a blanker array controller 21, a deflector controller 22, a detection processor 23, a focus controller 24, a stage controller 25, a main controller 26, and a generator 27. The blanker array control unit 21 individually controls a plurality of blankers constituting the blanker array 7. The deflector control unit 22 controls the deflector 10. The detection processing unit 23 processes a signal from the semiconductor detector 14. The focus control unit 24 controls the focal position of the reduction electron optical system 8 by adjusting the focal length of the focus coil 12. The stage controller 25 controls (drives) the substrate stage 13 based on the measurement result of the laser interferometer that measures the position of the substrate stage 13. The main control unit 26 controls the blanker array control unit 21, the deflector control unit 22, the detection processing unit 23, the focus control unit 24, and the stage control unit 25, and manages the entire drawing apparatus 100. The generation unit 27 generates drawing data for drawing a target pattern to be drawn on the substrate 9.

  The drawing process of the drawing apparatus 100 will be described with reference to FIG. The main control unit 26 performs a drawing process of drawing a target pattern on the substrate 9 by controlling the charged particle beam based on the drawing data input from the generating unit 27. Specifically, the main control unit 26 controls the deflector 10 via the deflector control unit 22 to deflect a plurality of charged particle beams. At this time, the main control unit 26 individually operates (ON or OFF) the blankers constituting the blanker array 7 based on the command value corresponding to the pixel to be irradiated with the charged particle beam via the blanker array control unit 21. ) Each charged particle beam raster scans the corresponding element region EF on the substrate 9, as shown in FIG. Element regions EF of each charged particle beam are set so as to be adjacent two-dimensionally. Therefore, the charged particle beam is irradiated to the subfield SF composed of a plurality of element regions EF irradiated with the charged particle beam simultaneously. When the drawing (exposure) of one subfield SF is completed, the main control unit 26 controls the deflector 10 via the deflector control unit 22 to draw the next subfield SF, and thereby a plurality of charged particles. Deflect the line. At this time, since the subfield changes due to the deflection of the deflector 10, the aberration when each charged particle beam is reduced and projected via the reduction electron optical system 8 also changes.

  In the present embodiment, the generation unit 27 generates drawing data by adding a constant component pattern (auxiliary pattern) to both ends (both ends) of the target pattern. Accordingly, when generating the drawing data, the generation unit 27 determines a pattern of a certain component to be added to both ends of the target pattern, that is, an auxiliary pattern. With reference to FIG. 4, determination of auxiliary patterns to be added to both ends of the target pattern will be described.

  In S102, a plurality of additional patterns are set by adding each of the plurality of auxiliary patterns to both ends of the target pattern. In S104, for each of the plurality of additional patterns set in S102, a profile (intensity distribution of the charged particle beam on the substrate 9) necessary for drawing the additional pattern is generated.

  Specifically, in S102 and S104, as shown in FIG. 5, an additional pattern is set by adding a fixed component auxiliary pattern to pixels located at both ends of the target pattern among a plurality of pixels. Here, the ratio of the constant component added as the auxiliary pattern is, for example, the ratio of the area occupied by the pattern in each pixel (occupancy ratio), that is, the line width of the pattern, such as α and β described in FIG. Can be used. Further, it is assumed that a certain component added as an auxiliary pattern (that is, the line width of the auxiliary pattern) is smaller than the width of a pixel which is a drawing unit by the charged particle beam. As shown in FIG. 5, in this embodiment, the constant component of the auxiliary pattern added to the pixels PL and PR where the left edge and the right edge of the target pattern are respectively positioned is γ. Accordingly, in S102, a plurality of additional patterns obtained by adding each of the plurality of auxiliary components of the constant component γ are set. In S104, a profile I is generated when a charged particle beam is irradiated to each of a plurality of additional patterns obtained by adding each of a plurality of auxiliary patterns of a certain component γ. For example, by convolving the intensity of the charged particle beam with the dose amount of each pixel, a plurality of profiles I corresponding to the plurality of additional patterns are generated.

  In S106, the intensity of the charged particle beam incident on each pixel is adjusted for each of the plurality of profiles I generated in S104. In S108, the line width CD and position Pos of the pattern (second pattern) drawn on the substrate 9 from the profile I ′ for each of the plurality of profiles I ′ whose charged particle beam intensity is adjusted in S106. calculate.

  As shown in FIG. 5, in the present embodiment, since the auxiliary pattern of the constant component γ is added to the target pattern, the total pattern is compared with the case where the auxiliary pattern is not added (that is, only the target pattern). Profile I increases. Accordingly, when the line width of the pattern is calculated from the profile I using the same exposure threshold Th as when no auxiliary pattern is added, the line width of the calculated pattern becomes larger than the line width of the target pattern. Therefore, in S106, the intensity of the charged particle beam incident on each pixel is adjusted so that the profile I becomes the profile I '. For example, the profile I 'is generated by adjusting the profile I so that the intensity of the charged particle beam irradiated to the position on the substrate 9 corresponding to the target pattern is lowered.

  An example of adjusting the intensity of the charged particle beam incident on each pixel will be described. For example, in FIG. 5, the constant component γ of the auxiliary pattern added to the target pattern is set to 0.1. In this case, the intensity (dose amount) of the charged particle beam set for each pixel for drawing the additional pattern is 0.1, 1, 1, 0.1 in order from the pixel PL to the pixel PR. . On the other hand, the intensity of the charged particle beam set in each pixel for drawing the target pattern is 1 and 1, and the total value (total dose) is 2. Therefore, in the present embodiment, the intensity of the charged particle beam set for each pixel is adjusted to draw the additional pattern so as to be equal to the total dose required to draw the target pattern. For example, in this embodiment, since the total value of the charged particle beam intensity set for each pixel to draw the additional pattern is 2.2 (= γ + 1 + 1 + γ), the charged particle beam intensity in each pixel is uniform. M = 2 / 2.2 = 2 / (2 + 2γ) = 1 / (1 + γ) times.

  However, as described above, even if the profile I ′ is generated by adjusting the intensity of the charged particle beam in each pixel so that the total dose amount becomes equal (constant), the pattern drawn on the substrate 9 The line width is not necessarily the line width of the target pattern. Accordingly, a plurality of magnifications (ratio) are set with the magnification M described above as an initial value, and the line width of the pattern drawn on the substrate 9 is the line width of the target pattern while generating the profile I ′ using each magnification. It is preferable to determine a magnification such that

  When calculating the line width CD and the position Pos of the pattern drawn on the substrate 9 from the profile I ′, first, the left edge and the right edge that are the intersections of the profile I ′ and the exposure threshold Th are obtained. . Then, the difference between the left edge and the right edge is calculated as the line width CD of the pattern, and the midpoint between the left edge and the right edge is calculated as the pattern position (center position) Pos.

  FIG. 6 shows the positions of the left edge and the right edge, the positions of the left edge and the right edge, and the ideal positions with respect to the position equal to or smaller than the pixel size with respect to the additional pattern to which the auxiliary pattern of the constant component γ is added at both ends of the target pattern. It is a figure which shows position shift with a position. In FIG. 6, the difference between the left edge and right edge deviation corresponds to a line width error, and the midpoint of the position deviation corresponds to a position error.

  FIG. 7 is a diagram showing a line width and a position error at a position equal to or smaller than the pixel size of the pattern calculated in S108 when the constant component γ of the auxiliary pattern is 5% to 35%. Referring to FIG. 7, it can be seen that the line width and the position error of the pattern at the position equal to or smaller than the pixel size differ depending on the constant component γ (value) of the auxiliary pattern.

  In S110, based on the line width CD and position Pos of the pattern calculated from the plurality of profiles I ', a fixed component γ (that is, a fixed component auxiliary pattern) to be added to the target pattern as an auxiliary pattern is determined. For example, a pattern in which the difference between the line width CD and position Pos of the pattern calculated from the plurality of profiles I ′ and the line width and position of the target pattern is within an allowable range is specified. Then, the auxiliary pattern (the constant component γ) added to the additional pattern corresponding to the specified pattern is determined as the auxiliary pattern (the constant component) added to the target pattern.

  As described above, in this embodiment, a plurality of pixels corresponding to the target pattern are set, and an intensity distribution corresponding to the width of the target pattern is obtained on the substrate based on the intensity distribution of the charged particle beam at the plurality of pixels. Thus, the preset intensity distribution is adjusted. Here, the charged particle beam intensity distribution in a plurality of pixels refers to a charged particle beam having a preset intensity that is different between the pixel corresponding to the end of the target pattern and the other pixels, to the plurality of pixels described above. It is the intensity distribution of the charged particle beam obtained in this case.

  FIG. 8 is a diagram showing the line width error and the position error of the pattern at the pattern position equal to or smaller than the pixel size shown in FIG. 7 in the range for each ratio of the constant component γ of the auxiliary pattern. In FIG. 8, the required accuracy (allowable range) for the line width error of the pattern is indicated by CD_Th, and the required accuracy (allowable range) for the pattern position error is indicated by Pos_Th. In this case, 15% or 20% can be selected as the fixed component γ of the auxiliary pattern that simultaneously satisfies the required accuracy of the line width error and the position error of the pattern. In other words, 15% or 20% is determined as the fixed component of the auxiliary pattern added to the target pattern.

  Further, as shown in FIG. 9, the required accuracy Pos_Th for the pattern position error may be as severe as the required accuracy CD_Th for the pattern line width error. In this case, if the constant component γ of the auxiliary pattern is 15%, the required accuracy Pos_Th of the pattern position error is not satisfied. Accordingly, 20% is selected as the constant component γ of the auxiliary pattern that simultaneously satisfies the required accuracy of the line width error and the position error of the pattern.

  As described above, in determining the auxiliary pattern, the ratio of the constant component γ to be added to the target pattern as the auxiliary pattern may be determined so as to satisfy the required accuracy of the line width error and the position error of the pattern simultaneously. Then, the generation unit 27 generates a pattern obtained by adding the auxiliary pattern of the constant component determined in S110 to both ends of the target pattern and data indicating the intensity distribution (that is, the intensity (intensity distribution) of the charged particle beam adjusted in S106). Generate as drawing data.

  When the drawing apparatus 100 is a multi-charged particle beam type drawing apparatus, the diameters of a plurality of charged particle beams for drawing on the substrate 9 may be different. In such a case, as shown in FIG. 10, the ratio of the constant component γ of the auxiliary pattern may be determined for each of the plurality of charged particle beams (that is, for each charged particle beam diameter).

  In S202, the respective diameters of the plurality of charged particle beams are detected using the semiconductor detector 14. In S204, a charged particle beam having one diameter, that is, one charged particle beam is selected as a target charged particle beam from the diameters of the plurality of charged particle beams detected in S202.

  In S206, a plurality of additional patterns obtained by adding each of a plurality of auxiliary patterns to both ends of the target pattern are set for the target charged particle beam selected in S204, as in S102.

  In S208, similarly to S104, for each of the plurality of additional patterns set in S206, a profile (intensity distribution of the charged particle beam on the substrate 9) necessary for drawing the additional pattern is generated.

  In S210, as in S106, the intensity of the charged particle beam incident on each pixel is adjusted for each of the plurality of profiles generated in S208.

  In S212, as in S108, the line width and position of the pattern drawn on the substrate 9 are calculated from each of the plurality of profiles whose charged particle beam intensity is adjusted in S210.

  In S214, for the target charged particle beam selected in S204, as in S110, based on the line width and position of the pattern calculated in S212, a constant component γ (that is, a constant component) to be added to the target pattern as an auxiliary pattern. The auxiliary pattern).

  In S216, it is determined whether or not all the diameters of the plurality of charged particle beams detected in S202 are selected as target charged particle beams. If all the diameters of the plurality of charged particle beams are not selected as the target charged particle beam, the process proceeds to S204, and the charged particle beam having the next diameter is selected as the target charged particle beam. If all the diameters of the plurality of charged particle beams are selected as target charged particle beams, the process is terminated.

  As described above, in the multi-charged particle beam type drawing apparatus, the auxiliary pattern may be determined according to the diameter of each charged particle beam. This makes it possible to reduce drawing errors due to fluctuations in the diameter of the charged particle beam, which is advantageous for improving drawing accuracy.

  FIG. 11 is a diagram showing a line width error and a position error with respect to a ratio of a plurality of constant components γ added as auxiliary patterns with respect to charged particle beam diameters R1, R2, and R3. In FIG. 11, each of the line width error and the position error of the pattern at the pattern position equal to or smaller than the pixel size is shown as a range for each ratio of the constant component γ of the auxiliary pattern. Referring to FIG. 11, it can be seen that the line width error and the position error of the pattern at the subpixel position differ depending on the diameter of the charged particle beam. For example, when the diameter of the charged particle beam is R1, when the auxiliary component has a constant component γ of 15%, the pattern line width error is minimized, but the pattern position error is large. When the diameter of the charged particle beam is R2, when the auxiliary component has a constant component γ of 20%, the line width error and the position error of the pattern are minimum values. In FIG. 11, the required accuracy regarding the line width error of the pattern is indicated by CD_Th, and the required accuracy regarding the position error of the pattern is indicated by Pos_Th. In this case, the constant component γ of the auxiliary pattern that simultaneously satisfies the required accuracy of the line width error and the position error of the pattern is 25% when the diameter of the charged particle beam is R1, and the diameter of the charged particle beam is R2. 20%, and 15% when the diameter of the charged particle beam is R3.

  Here, with reference to FIG. 12, the determination of the magnification M used when adjusting the intensity of the charged particle beam of each pixel (S106) will be described. In S302, a plurality of magnifications (ratio) for adjusting the intensity of the charged particle beam of each pixel are set for one auxiliary pattern (auxiliary pattern of a certain component).

  In S304, with respect to the profile corresponding to the additional pattern to which the auxiliary pattern described above is added, the plurality of profiles are generated by adjusting the intensity of the charged particle beam using each of the multiple magnifications set in S302. For example, when M1, M2, and M3 are set as a plurality of magnifications, the intensity of the charged particle beam at each pixel is adjusted using each magnification to generate three profiles I1, I2, and I3.

  In S306, for each of the plurality of profiles generated in S304, the line width and position of the pattern drawn on the substrate 9 are calculated from the profiles. In S308, based on the line width and position of the pattern calculated in S306, the magnification M used when adjusting the intensity of the charged particle beam of each pixel from the multiple magnifications set in S302 (S106) is determined.

  FIG. 13 is a diagram illustrating a result of calculating the line width of the pattern at the sub-pixel position using the same exposure threshold Th for each of the profiles I1, I2, and I3 generated in S304. Here, with respect to the line width of interest (22 nm), the line width of the pattern at a position equal to or smaller than the pixel size is adjusted so that the maximum line width and the minimum line width are centered with respect to 22 nm. Accordingly, the magnification M2 (profile I2) is selected as the magnification M used when adjusting the intensity of the charged particle beam of each pixel. Thereby, a line width error at an arbitrary sub-pixel position of the pattern can be minimized.

  Hereinafter, the effect of this embodiment (that is, the case where drawing data is generated by adding auxiliary patterns of a certain component to both ends of the target pattern) will be qualitatively described.

  First, a mechanism for generating a systematic error at a subpixel position when an auxiliary pattern having a certain component is not added to both ends of the target pattern will be described. For example, when a pattern is drawn with two pixels, as shown in FIG. 14, when a pattern is drawn with three pixels shifted as shown in FIG. 14, the profile obtained by integrating the intensity distribution corresponding to each pixel is I Changes from Isub to Isub. Thus, when generating a profile with two pixels, the interaction (interaction) of the left and right edges cannot be ignored. As shown by region A in FIG. 14, since the intensity distribution IL at the pixels near the left edge is large, the influence on the right edge due to the decrease in the intensity of the left edge due to the subpixel positional shift may be ignored. Can not. The decrease dLy in the intensity of the right edge due to the decrease in the intensity of the left edge Ly cancels out the increase dRy in the intensity of the right edge itself in the vicinity of the right edge. Therefore, the intensity of the right edge only increases by Ry, and the right edge positional deviation Rx is less sensitive than the left edge positional deviation Lx. As a result, the pattern line width error and position error increase.

  On the other hand, when an auxiliary pattern having a constant component is added to both ends of the target pattern, as shown in FIG. 15, when the pattern to which the auxiliary pattern is added is shifted by the subpixel position, the interaction between the left and right edges (interaction) There is an effect to suppress. In this case, as indicated by region B in FIG. 15, the intensity distribution IL at the pixels near the left edge is small. In this state, if the pattern to which the auxiliary pattern is added is shifted by the sub-pixel position, the decrease in the intensity of the right edge due to the decrease in the intensity of the left edge is small, so the amount offset by the right edge is relaxed. The Therefore, the left edge intensity decrease Ly and the right edge intensity increase Ry substantially coincide with each other, and the right edge positional deviation Rx and the left edge positional deviation Lx are approximately the same. As a result, the line width error and position error of the pattern are reduced.

  According to the drawing apparatus 100 of the present embodiment, the line width error and the position error of the pattern drawn on the substrate 9 can be reduced. Therefore, the drawing apparatus 100 can provide an article such as a high-quality device (semiconductor integrated circuit element, liquid crystal display element, etc.) that achieves excellent drawing accuracy and is economical with high throughput. Here, an article such as a device is a step of drawing a pattern on a substrate (wafer, glass plate, etc.) coated with a resist (photosensitive agent) using the drawing apparatus 100 and a step of developing the substrate on which the pattern is drawn. And other known processes.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

  As mentioned above, although preferable embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, the present invention can be applied not only to a drawing apparatus using a charged particle beam but also to a drawing apparatus using an ion beam.

Claims (8)

A drawing apparatus for drawing on a substrate with a charged particle beam,
A generator for generating drawing data;
A charged particle optical system that generates the charged particle beam based on the drawing data generated by the generation unit, and
The generator is
Set multiple pixels corresponding to the target pattern with width,
Among the plurality of pixels, the pixel corresponding to the end portion of the target pattern and the other particles are obtained on the substrate when charged particle beams having different preset intensities are applied to the plurality of pixels. Based on the intensity distribution of the charged particle beam, the drawing data is generated by adjusting the preset intensity distribution so that an intensity distribution corresponding to the width is obtained on the substrate.
A drawing apparatus characterized by that.   The generating unit adjusts the preset intensity so that a total value of the intensity of charged particle beams given to the plurality of pixels becomes a preset value according to the width. The drawing apparatus according to claim 1.   The drawing apparatus according to claim 2, wherein the generation unit adjusts the preset intensity based on a ratio of the preset value to the total value.   4. The drawing apparatus according to claim 1, wherein the preset intensity is set based on an occupation rate of the target pattern in each of the plurality of pixels. 5. The drawing apparatus performs drawing on the substrate with a plurality of charged particle beams,
5. The generation unit according to claim 1, wherein the generation unit generates the drawing data based on an intensity distribution on the substrate of each of the plurality of charged particle beams. 6. Drawing device. A generation method for generating the drawing data used in a drawing apparatus for drawing on a substrate with a charged particle beam generated by a charged particle optical system based on the drawing data,
Setting a plurality of pixels corresponding to a target pattern having a width;
Among the plurality of pixels, the pixel corresponding to the end portion of the target pattern and the other particles are obtained on the substrate when charged particle beams having different preset intensities are applied to the plurality of pixels. Generating the drawing data by adjusting the preset intensity so that an intensity distribution corresponding to the width is obtained on the substrate based on an intensity distribution of a charged particle beam;
A generation method characterized by comprising:   A program causing a computer to execute each step of the generation method according to claim 6. Drawing on a substrate using the drawing apparatus according to any one of claims 1 to 5,
Developing the substrate on which the drawing has been performed in the step;
A method for producing an article comprising:

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