JP2012019066A - Charged particle beam lithography method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electronic beam lithography method and apparatus capable of performing a proximity effect correction with higher accuracy as charged particle beam method and apparatus.SOLUTION: The charged particle beam lithography apparatus for performing the proximity effect correction comprises: a proximity effect correction amount calculation step, in which a drawing pattern included in a region obtained by dividing a drawing region is divided into a shot unit, resize processing is performed with a predetermined resize value according to a size of the drawing pattern (beam graphic) for the drawing pattern in the shot unit, and a proximity effect correction amount is calculated based on the drawing pattern in the shot unit obtained by the resize processing; and a drawing step of drawing a desired pattern by controlling a shot time of a charged particle beam based on the proximity effect correction amount, and also controlling a size and a position of the charged particle beam based on the drawing pattern in the shot unit obtained by the resize processing.

Description

  The present invention relates to a charged particle beam drawing method and apparatus for drawing a desired pattern by deflecting an electron beam irradiated to a drawing material, and more particularly, calculation of a stored energy ratio performed by proximity effect correction. Regarding the method.

  FIG. 8 is a diagram showing an example of a variable area electron beam drawing apparatus. The electron beam generated from the electron gun 1 is irradiated onto the first shaping aperture 4 through the irradiation lens 3. 2a is a blanker for turning on / off the electron beam 2. The first shaping aperture opening image is formed on the second shaping aperture 6 by the shaping lens 5, and the position of the image formation is controlled by the shaping deflector 7, and the beam shape and size can be changed. The image formed by the second shaping aperture 6 is irradiated onto the drawing material 10 through the reduction lens 8 and the objective lens 9. The irradiation position on the drawing material 10 can be changed by the positioning deflector 11.

  The semiconductor circuit pattern is created by CAD, and is described in a special form (format) composed of digital numerical values in order to efficiently express a large amount of contents. Therefore, the semiconductor circuit pattern cannot be input to the drawing apparatus as it is. Therefore, data that has been previously converted into a format that can be handled by the apparatus or subjected to compression processing is input as drawing pattern data.

  The input drawing pattern data is divided into beam figures by the data transfer circuit 20 (the drawing pattern is divided for each shot unit) and sorted, and supplied to the shaping deflector control circuit 13 and the positioning deflector control circuit 14. The At the same time, irradiation time data is supplied to a blanking control circuit 15 that controls on / off of electron beam irradiation. The irradiation time data is calculated by the irradiation time calculation circuit 21 in consideration of various corrections such as proximity effect correction for the set irradiation amount. The blanking control circuit 15 controls on / off of the blanker 2a.

  Reference numeral 12 denotes a stage on which the drawing material 10 is placed, 16 denotes a stage driving circuit for driving the stage 12, and 17 denotes a stage driving control circuit for controlling the stage driving circuit 16. Reference numeral 18 denotes a pattern data disk in which drawing patterns are stored, and reference numeral 30 denotes a control CPU that controls the overall operation of the apparatus. For example, a computer is used as the control CPU 30.

  Reference numeral 22 denotes another correction circuit that gives correction data other than the proximity effect correction to the irradiation time calculation circuit 21. Reference numeral 23 denotes a beam graphic division processing circuit that divides pattern data from the control CPU 30 into beam graphics (divides a drawing turn for each shot unit), and 24 receives an output from the beam graphic division processing circuit 23 to receive drawing data. This is a sorting processing circuit that performs rearrangement and the like and sends control signals to the positioning deflector control circuit 14, the shaping deflector control circuit 13, and the irradiation time calculation circuit 21.

  Reference numeral 40 denotes a proximity effect correction circuit, which is a correction value calculation circuit that receives a stored energy ratio calculation circuit 41 and an output of the energy ratio calculation circuit 41 to calculate a correction value for proximity effect correction. It is sent to the circuit 21.

  As a conventional device of this type, a plurality of rectangular patterns having the same dimensions are prepared, at least one of which draws a rectangular pattern with a single shot, and the rest is a pattern with straight lines parallel to one side of the rectangular pattern. The pattern size in the direction perpendicular to the dividing line is measured using an SEM for the actual pattern obtained by dividing the pattern into two shots and developing them. Or the technique of evaluating the dimensional accuracy of a variable shaped beam by investigating the relationship with a division | segmentation position is known (for example, refer patent document 1).

  In addition to the proximity effect correction processing at the time of data conversion, an apparatus is known that performs etching correction processing to perform exposure amount correction and resizing (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 9-186070 (paragraphs 0015 to 0025, FIG. 2) JP-A-11-154635 (paragraphs 0032 to 0037, FIG. 2)

  In a variable area electron beam lithography apparatus using an electron beam with an acceleration voltage of 50 kV, a pattern dimension error caused by the effect of accumulated energy due to backscattering is corrected by adjusting an irradiation amount (irradiation time). This correction is called proximity effect correction. The proximity effect is a phenomenon in which the resist is exposed to light by backscattered electrons scattered through the resist film and scattered on the surface of the substrate, resulting in a pattern dimensional error. When an electron beam with an acceleration voltage of 50 kV is used, the influence range is Is about 50 μm square.

  The correction amount Smod by the proximity effect correction is shown in the equation (1).

Where η is a backscattering coefficient, C2 is a coefficient representing the relationship between incident energy and a resolution threshold,
Org represents the reference stored energy ratio, and Ebp represents the stored energy ratio.

The accumulated energy ratio Ebp due to backscattering that changes according to the density of the drawing pattern is obtained by dividing a rectangular large and small pattern as shown in FIG. 9 into grid cells of uniform size, and for each cell (section). Calculate the accumulated energy ratio due to backscattering. The stored energy ratio Ebp _{m, n} due to backscattering for each cell is expressed by the following equation (2). Here, Eim _{, n} represents the ratio occupied by the drawing pattern in the divided cells, EIDi _{, j} represents the accumulated energy intensity distribution due to backscattering, and r represents the calculation area of the accumulated energy ratio due to backscattering. Yes.

The stored energy intensity distribution EID _{i, j} due to backscattering is represented by a Gaussian distribution having a range of βb as shown in the equation (3), and βb is called a backscattering diameter. The ratio Eim _{, n} occupied by the drawing pattern in the divided cells is calculated based on the drawing pattern data.

  On the other hand, the variable area electron beam drawing apparatus measures the size of the electron beam used for drawing and the focus state of the electron beam before drawing, and adjusts the electron beam based on the measurement result. FIG. 10 is a diagram showing a configuration example of an apparatus used for such an electron beam measurement.

  In the figure, 50 is an electron beam to be measured. Although not shown, the electron beam 50 has a rectangular cross section formed by two rectangular slits and a deflector provided between the two rectangular slits. The electron beam 50 is focused by the final stage lens 51 and further deflected by the electrostatic deflector 52. A knife edge member 53 is disposed below the deflector 52. The knife edge member 53 is provided with a rectangular opening, and each inside thereof is formed thin and linear.

  An aperture 54 that cuts the scattered electron beam is provided below the knife edge 53, and a Faraday cup 55 that detects the amount of current of the electron beam is further disposed below the aperture 54.

  In such a configuration, when the rectangular electron beam 50 is scanned by the deflector 52, the electron beam 50 is gradually blocked by the knife edge member 53, and the amount of the electron beam incident on the Faraday cup 55 decreases. When the electron beam 50 is completely blocked by the knife edge member 53, the detection current of the Faraday cup 55 becomes zero.

FIG. 11A shows the detected current of the Faraday cup 55. When this detected current is differentiated once, the signal of FIG. 11B is obtained. N data Ai (i is a scanning position, i = 1, 2,..., N) of the primary differential signal, a is 1/2 of the beam size, b is the beam position, and c1 is the focus of the first slit. The following evaluation function Fi = (a, b, c1, c2) in which information c2 is the focus information of the second slit
= Tanh {(i + a−b) / c1} −Tanh {(i−a−b) / c2} and parameters a and b that minimize the sum of squares of the difference between the data Ai and the evaluation function Fi. , C1 and c2 are determined to obtain the beam size and the focus information.

  However, as described above, although the size of the electron beam used for drawing is adjusted, drawing may be performed by changing the size of the electron beam used for drawing in order to match the target design value. For example, in the photomask manufacturing process, a predetermined pattern is drawn on the resist film formed on the drawing material 10 by an electron beam. Then, the drawing material undergoes processing such as baking (heating), development, etching, and the like.

  In this way, since the pattern drawn by the electron beam is formed through the process processing, it is affected by the process processing, and there may be a deviation between the actually finished pattern size and the target design value. This pattern dimension deviation is corrected.

  In this case, the intensity of the shaping deflector 7 (see FIG. 8) is adjusted, and the electron beam size is intentionally changed for drawing. In the proximity effect correction described above, the stored energy ratio due to backscattering that changes according to the density of the drawing pattern is calculated based on the drawing pattern data, and the proximity effect correction calculation is performed.

  However, since the drawing is performed by intentionally changing the size of the electron beam, if the accumulated energy ratio due to backscattering is calculated based on the drawing pattern data, the calculated energy energy ratio due to backscattering is calculated. Since the amount of change in size is not included, the calculated stored energy ratio due to backscattering is not correct and includes an error.

  The present invention has been made in view of such problems, and can calculate the stored energy ratio by backscattering including the amount of change in the size of the electron beam, so that the proximity effect correction can be performed with higher accuracy. It is an object of the present invention to provide an electron beam drawing method and apparatus capable of performing the same.

  In a variable area electron beam lithography apparatus using an electron beam with an acceleration voltage of 50 kV, a pattern dimension error caused by the effect of accumulated energy due to backscattering is corrected by adjusting an irradiation amount (irradiation time). This correction is called proximity effect correction. In proximity effect correction, in order to estimate the effect of accumulated energy due to backscattering, the pattern to be drawn is divided into a uniform grid pattern, and the accumulated energy ratio is calculated for each divided cell (section). .

  In order to solve the above problems, the present invention has the following configuration.

  (1) The invention described in claim 1 draws a predetermined pattern on a material to be drawn using a charged particle beam, divides the drawing area, and determines the area from the proportion of the drawing pattern included in the divided area In the charged particle beam drawing method in which a proximity effect correction amount is calculated, a charged particle beam is shot in consideration of the correction amount, and a desired pattern is drawn, a drawing pattern included in the divided region is calculated. Divide into shot units, resize the drawing pattern for each shot with a resize value determined in advance according to the size of the drawing pattern for each shot, and correct the proximity effect based on the resized drawing pattern for each shot unit A proximity effect correction amount calculation step for calculating the amount, and charged particles based on the correction amount from the proximity effect correction amount calculation step And a drawing step of drawing a desired pattern by controlling the size and position of the charged particle beam based on the resized shot-by-shot drawing pattern. To do.

  (2) In the invention according to claim 2, in the drawing step, the shot time of the charged particle beam is controlled based on a correction value from the proximity effect correction amount calculation step, and the proximity effect correction amount calculation step Control the size and position of the charged particle beam based on the shot unit drawing pattern that has been resized with a resize value determined in advance according to the shot unit drawing pattern size based on the shot unit drawing pattern. The pattern is drawn.

  (3) In the invention according to claim 3, the resize value is obtained by baking, developing, or etching a drawing material on which a desired pattern is drawn using a charged particle beam, and a pattern size actually finished. It is a difference from the design pattern size.

  (4) In the invention according to claim 4, the resize value has a resize value in the X direction and a resize value in the Y direction, and is a value corresponding to the size in the X direction and the Y direction of the pattern to be drawn. Features.

  (5) The invention according to claim 5 is characterized in that the resize value is stored in a memory in advance.

  (6) The invention according to claim 6 is a charged particle beam drawing apparatus for drawing a predetermined pattern on a drawing material using a charged particle beam, the charged particle beam generating means for generating a charged particle beam, Blanking means for turning on / off irradiation of the charged particle beam from the charged particle beam generating means, beam shaping deflection means for forming the charged particle beam into a shaped beam, and a desired beam on the drawing material. A beam positioning deflection unit that adjusts the position to the position, and a proximity effect correction amount calculation unit that divides the drawing region and calculates a proximity effect correction amount in the region from the ratio of the drawing pattern included in the divided region. In the charged particle beam drawing apparatus, the proximity effect correction amount calculating means converts the drawing pattern included in the divided area into a drawing unit drawing pattern. And a resize processing means for resizing with a resize value determined in advance according to the size of the drawing pattern for each shot, and proximity effect correction based on the resized processing for the shot unit for the shot unit. The shot time of the charged particle beam is controlled by the blanking means based on the correction amount calculated by the quantity calculating means, and the size of the charged particle beam is controlled by the shaping deflecting means based on the resized shot-by-shot drawing pattern. The position of the charged particle beam is controlled by the beam positioning deflector means.

  (7) The invention according to claim 7 is a resize value determined in advance according to the size of the drawing pattern based on the drawing pattern of the shot unit from the drawing pattern dividing unit of the proximity effect correction amount calculating unit. A resize processing means for resizing is provided on the shaping deflection means side, and the shot time of the charged particle beam is controlled by the blanking means based on the correction amount calculated by the proximity effect correction amount calculating means. The shaping deflection unit controls the size of the charged particle beam based on the output, and the beam positioning deflection unit controls the position of the charged particle beam.

  (8) The invention according to claim 8 is characterized in that the resize processing means is connected to a memory.

  The present invention has the following effects.

  (1) According to the first aspect of the present invention, the proximity effect correction amount calculating step for calculating the proximity effect correction amount based on the resized drawing pattern for each shot unit, and the correction amount from the proximity effect correction amount calculating step And a drawing step of drawing a desired pattern by controlling the shot time of the charged particle beam based on the size and controlling the size and position of the charged particle beam based on the resized shot drawing pattern. Thus, it is possible to perform beam drawing with proximity effect correction accurately performed.

  (2) According to the invention described in claim 2, the resize processing is performed with a resize value determined in advance according to the size of the drawing unit of the shot unit based on the drawing unit of the shot unit in the proximity effect correction amount calculating step. Accurate drawing can be performed by controlling the size and position of the charged particle beam based on the drawing pattern in shot units.

  (3) According to the invention described in claim 3, a pattern actually finished by baking, developing, or etching a drawing material on which a desired pattern is drawn using a charged particle beam as the resize value. By using the difference between the size and the designed pattern size, accurate beam drawing can be performed.

  (4) According to the invention described in claim 4, by using the value in the XY two-dimensional direction as the resize value, the drawing in the two-dimensional direction can be performed accurately.

  (5) According to the invention described in claim 5, by storing the resize value in the memory in advance, an efficient resize process can be performed when the proximity effect correction is obtained.

  (6) According to the invention of claim 6, the shot time of the charged particle beam is controlled by the blanking means based on the correction amount calculated by the proximity effect correction amount calculation means based on the resized shot-by-shot drawing pattern. Proximity effect correction by controlling the size of the charged particle beam by the shaping deflection unit and controlling the position of the charged particle beam by the beam positioning deflector unit based on the resized shot-by-shot drawing pattern It is possible to perform the beam drawing with the accuracy.

  (7) According to the seventh aspect of the invention, the shot time of the charged particle beam is controlled by the blanking means based on the correction amount calculated by the proximity effect correction amount calculating means, and based on the output from the resizing processing means. By controlling the size of the charged particle beam with the shaping deflection means and controlling the position of the charged particle beam with the beam positioning deflection means, accurate beam drawing can be performed.

  (8) According to the invention described in claim 8, since the resizing processing means is connected to the memory, the resizing value stored in the memory is quickly read out, and an efficient resizing process is performed when proximity effect correction is obtained. Can be performed.

It is a block diagram which shows one Example of this invention. It is a figure which shows an example of the basic pattern which calculates | requires the variation | change_quantity of the line | wire width dimension of a figure pattern. It is a figure which shows the data table which consists of the resizing amount of the beam dimension X, and the resizing amount of the beam dimension Y. It is a figure which shows a division | segmentation drawing pattern. It is a figure which shows a division | segmentation drawing pattern. It is a figure which shows the example of drawing. It is a block diagram which shows the other Example of this invention. It is a figure which shows an example of a variable area type electron beam drawing apparatus. It is a figure which shows a drawing pattern. It is a figure which shows the structural example of the apparatus used for the measurement of an electron beam. It is a figure which shows the detection current of a Faraday cup, and its differential waveform.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is a charged particle beam drawing method and apparatus in which means for manually resizing the drawing pattern size divided into shot units in a proximity effect correction circuit with a predetermined resizing value is provided. FIG. 1 is a block diagram showing an embodiment of the present invention, and shows a variable area electron beam drawing apparatus. The same components as those of the electron beam drawing apparatus shown in FIG. 8 are denoted by the same reference numerals. 1 is different from FIG. 8 in that the beam graphic division processing circuit 23 is eliminated from the data transfer circuit 20, and a beam graphic division processing circuit 23a, a resizing processing circuit 60, and a memory 61 are provided in the proximity effect correction circuit 40. It is.

  The beam graphic division processing circuit 23 a in the proximity effect correction circuit 40 receives the pattern data from the control CPU 30, divides the drawing pattern for each short unit (hereinafter referred to as a beam graphic), and outputs it to the resizing processing circuit 60. The resize processing circuit 60 receives the output from the beam graphic division processing circuit 23a, reads the resize value from the memory 61 according to the size of each beam graphic, performs the resize processing based on the resize value, and stores it. This is output to the energy ratio calculation circuit 41 and the sorting processing circuit 24. The memory 61 stores resize values corresponding to the beam dimension X and the beam dimension Y of the beam figure obtained by the measurement.

  In the variable-area electron beam lithography apparatus configured as described above, first, the amount of change in the line width dimension of the graphic pattern that changes due to a process such as baking, development, etching, etc. after drawing is obtained. FIG. 2 shows an example of the basic pattern P for obtaining the change amount of the line width dimension of the graphic pattern. In this basic pattern, rectangular patterns having different dimensions in the X direction and the Y direction are arranged side by side, and the basic pattern P in the figure includes, for example, nine patterns whose dimensions in the X direction and the Y direction are different from 200 nm, 600 nm, and 1000 nm, respectively. It consists of a rectangular pattern.

  The drawing material 10 in which such a basic pattern P is drawn in a matrix by varying the control signal of the shaping deflector 7 and the control signal of the positioning deflector 11 of the variable area electron beam lithography apparatus is baked, developed, etc. Process evaluation is performed to produce an evaluation pattern. The line width dimension in the X direction and Y direction of each rectangular pattern in the evaluation pattern is measured with a length measuring device such as a CD-SEM.

  Then, the difference between the dimensions X and Y obtained by measuring the rectangular pattern and the design dimensions of each pattern becomes the resize values Rx and Ry of each beam figure. The resize values Rx and Ry have a negative sign when the measured dimension is larger than the design dimension, and a positive sign when the measured dimension is smaller than the design dimension.

Here, FIG. 3 shows a data table including the resizing amount of the beam dimension X and the resizing amount of the beam dimension Y corresponding to the dimension X and the dimension Y of the beam figure. Note that Rx ₁₁ , Ry ₁₁ ,..., Rx ₃₃ , Ry ₃₃ shown in the figure contain 18 resize values in nm units, but there may be more data tables. It is assumed that such a data table is stored in advance in the memory 61 of the resize processing circuit 60 in the proximity effect correction circuit 40 before drawing.

  The control CPU 30 reads the drawing pattern data from the pattern data disk 18 and sends it to the beam graphic division processing circuit 23a in the proximity effect correction circuit 40. The beam graphic division processing circuit 23a divides the transmitted drawing pattern data into large and small rectangular beam graphics. In the variable area type electron beam drawing apparatus, since the maximum beam size formed by the shaping deflector 7 is limited, the drawing pattern is divided so that the shaping electron beam is equal to or smaller than the maximum beam size.

  Next, the beam graphic division processing circuit 23 a sends the drawing division pattern data divided for each beam graphic to the resizing processing circuit 60. The resize processing circuit 60 reads each resize value from the memory 61 based on the X and Y dimensions for each beam graphic from the beam graphic division processing circuit 23a, and resizes each resize value for each beam graphic.

  Here, an example of resizing the drawing division pattern data divided for each beam graphic is shown. P1 in FIG. 4 is a large rectangular drawing pattern, P2 is a small rectangular drawing pattern, the large rectangular drawing pattern is a beam figure having an X dimension of 1000 nm and a Y dimension of 1000 nm, and the rectangular pattern P2 has an X dimension of 600 nm and a Y dimension of 1000 nm. This is divided drawing pattern data divided into beam figures.

When such divided drawing pattern data is sent to the resize processing circuit 60, the resize processing circuit 60 reads the respective resize values from the memory 61 based on the dimensions X and Y for each beam pattern in the divided drawing pattern. . For example, in the case of a beam pattern of 1000 nm (X) × 1000 nm (Y), the resizing amount Rx ₃₃ corresponding to the beam dimension X of 1000 nm and the resizing amount Ry ₃₃ corresponding to the beam dimension Y of 1000 nm are 600 nm (X) × 1000 nm. In the case of the beam diagram (Y), the resizing amount Rx ₂₃ corresponding to the beam dimension X of 600 nm and the resizing amount Ry ₂₃ corresponding to the beam dimension Y of 1000 nm are read from the memory 23a, respectively, and 1000 nm (X) × 1000 nm (Y ) The resizing values Rx ₃₃ and Ry ₃₃ are added to the X and Y dimensions of the beam graphic, and the resizing values Rx ₂₃ and Ry ₂₃ are added to the X and Y dimensions of the 600 nm (X) × 1000 nm (Y) beam graphic. Then, a beam figure of the divided drawing pattern data as shown in FIG. 5 is produced. In this embodiment, the resize values Rx ₃₃ , Ry ₃₃ , Rx ₂₃ , and Ry ₂₃ of the X dimension and the Y dimension for each beam pattern in FIG. 3 are negative.

  When the resizing value corresponding to the dimension X and the dimension Y of the beam figure meeting the request from the resizing processing circuit 60 is not stored in the memory 61, an interpolation operation circuit (not shown) in the resizing processing circuit 60 is shown. The interpolation calculation circuit reads several dimensions and resizing values close to the dimensions X and Y of the beam figure that meet the requirements, and performs interpolation and extrapolation calculations to meet the requirements. Since the resizing value corresponding to the dimension X and the dimension Y of the combined beam figure is obtained, this resizing value is obtained, and this resizing value is sent to the resizing processing circuit 60. Is called.

  Next, the resizing processing circuit 60 sends the resized divided drawing pattern data to the accumulated energy ratio calculating circuit 41 and the sorting processing circuit 24. In the stored energy ratio calculation circuit 41, the resized patterns P1 and P2 for each beam pattern shown in FIG. 5 are divided into a uniform grid as shown in FIG. The accumulated energy ratio due to scattering is calculated and sent to the correction arithmetic circuit 42.

Incidentally, accumulated energy ratio Ebp m by backscattering of each cell as described above, the calculation of _n is 2 represented by the formula, Ei m, _n are occupied by drawing pattern in the cells divided in (2) The ratio, r is the calculation area of the accumulated energy ratio due to backscattering, and the accumulated energy intensity distribution EIDi, j due to backscattering is expressed by equation (3).

  The correction calculation circuit 42 substitutes the calculated stored energy ratio into the equation (1), calculates a correction value by proximity effect correction, and sends it to the irradiation time calculation circuit 21 in the data transfer circuit 20. On the other hand, the sorting processing circuit 24 performs sorting processing based on the resized drawing division pattern data, and sends this data to the shaping deflector control circuit 13, the deflector control circuit 14, and the irradiation time calculation circuit 21. It is done.

  Then, the shaping deflector control circuit 13 controls the shaping deflector 7 based on the output data of the sorting processing circuit 24, and the positioning deflector control circuit 14 determines the positioning deflector based on the output data of the sorting processing circuit 24. 11, the irradiation time calculation circuit 21 calculates the irradiation time based on the output data from the sorting processing circuit 24 and the output data from the correction value calculation circuit 42, and blanking is performed based on the irradiation time of the calculation result. The control circuit 15 controls the blanker 2a.

Such a control makes it possible to calculate the accumulated energy ratio due to backscattering including the amount of change in the electron beam size, so that the proximity effect correction can be performed with higher accuracy.
[Example 2]
FIG. 7 is a block diagram showing another embodiment of the present invention. The present invention is a charged particle beam drawing method and apparatus provided with means for resizing processing on the shaping deflector control circuit and positioning deflector control circuit side in addition to the proximity effect correction circuit. 1 and 8 are denoted by the same reference numerals. 7 is different from the electron beam drawing apparatus of FIG. 8 in that a beam figure division processing circuit 23b is provided in the data transfer circuit 20, the connection path of the resize processing circuit 60 in the proximity effect correction circuit 40 is changed, and the resizing is performed. The processing circuit 60 receives the input data from the beam figure division processing circuit 23a, and makes a connection path for sending the output data to the stored energy ratio calculation circuit 41. The shaping deflector control circuit 13, the positioning deflector control circuit 14, and the sorting processing circuit 24 are used. A resize processing circuit 60 'is provided between the memory 61' and a memory 61 'connected to the resize processing circuit 60'.

  In the memory 61 ′, a data table including data in the memory 61, that is, a resizing amount of the beam dimension X and a resizing amount of the beam dimension Y corresponding to the dimension X and the dimension Y of the beam figure is stored.

  In the variable area electron beam drawing apparatus having such a configuration, the control CPU 30 reads the drawing pattern data from the pattern data disk 18, and the beam figure division processing circuit 23 a in the proximity effect correction circuit 40 and the beam figure in the data transfer circuit 20. The data is sent to the dividing circuit 23b. The beam graphic division processing circuit 23 a in the proximity effect correction circuit 40 divides the pattern of the received drawing pattern data for each beam graphic and sends it to the resizing processing circuit 60.

  The resizing processing circuit 60 reads each resizing value from the memory 61 based on the beam dimension X and beam dimension Y for each beam graphic, and adds each resizing value to the X dimension and Y dimension for each beam graphic. Processed and sent to the stored energy ratio calculation circuit 41. The accumulated energy ratio calculation circuit 41 divides the resized pattern for each beam figure into a uniform grid, calculates the accumulated energy ratio by backscattering for each cell (section), and a correction value calculation circuit 42. The correction value calculation circuit 42 obtains a correction value by proximity effect correction by substituting the calculated stored energy ratio into the equation (1), and sends it to the irradiation time calculation circuit 21 in the data transfer circuit 20.

  On the other hand, the beam graphic division processing circuit 23 b sends the data obtained by dividing the pattern of the drawing pattern data sent from the control CPU 30 for each beam graphic to the sorting processing circuit 24. The sorting processing circuit 24 sorts the divided data, and sends the sorting data to the irradiation time calculation circuit 21 and the resizing processing circuit 60 '.

  Then, the resize processing circuit 60 ′ reads the resize value determined in advance according to the size of the beam graphic from the memory 61 ′ based on the divided drawing unit of the shot pattern, performs the resize processing for each beam graphic, and performs shaping. This is sent to the deflector control circuit 13 and the positioning deflector control circuit 14. The shaping deflector control circuit 13 controls the shaping deflector 7 and the positioning deflector control circuit 14 controls the positioning deflector 11 based on the drawing unit drawing pattern.

  The positioning deflector control circuit 14 controls the positioning deflector 11 based on the output data from the sorting processing circuit 24, and based on the output data from the sorting processing circuit 24 and the output data from the correction value calculation circuit 42. The irradiation time calculation circuit 21 calculates the irradiation time, and the blanking control circuit 15 controls the blanker 2a based on the irradiation time of the calculation result. Such a control makes it possible to calculate the accumulated energy ratio due to backscattering including the amount of change in the electron beam size, so that the proximity effect correction can be performed with higher accuracy.

  The positioning deflector control circuit 14 according to the second embodiment may set the center of one-shot drawing pattern as the beam positioning origin. In this case, the input data of the positioning deflector control circuit 14 must be a connection path for receiving the output data from the sorting processing circuit 24, not the output data from the resizing processing circuit 60 '.

  In the second embodiment, the output of the control CPU 30 is described as a connection path for sending the output of the control CPU 30 to the beam graphic division processing circuit 23 a of the proximity effect correction circuit 40 and the beam graphic processing circuit 23 b of the data transfer circuit 20. A connection path for sending to the beam figure division processing circuit 23 a of the proximity effect correction circuit 40 and sending the output of the beam figure division processing circuit 23 a to the resizing processing circuit 60 and the sorting processing circuit 24 of the data transfer circuit 20 may be used.

  The effects of the present invention are as follows. Even when the size of the electron beam used for drawing is intentionally changed, the proximity effect correction is applied with higher accuracy by calculating the ratio of stored energy due to backscattering, including the amount of change in the electron beam size. An electron beam drawing apparatus capable of performing this can be realized, and drawing with higher accuracy is possible.

  In addition, according to the present invention, it is possible to intentionally shift the size of the electron beam used for drawing, and it becomes easy to control the pattern dimensions that have undergone process processing such as baking, development, and etching.

DESCRIPTION OF SYMBOLS 1 Electron gun 2 Electron beam 3 Irradiation lens 4 1st shaping | molding aperture 5 Molding lens 6 2nd shaping | molding aperture 7 Molding deflector 8 Reduction lens 9 Objective lens 10 Drawing material 11 Positioning deflector 12 Stage 13 Molding deflector control circuit 14 Positioning Deflector control circuit 15 Blanking control circuit 16 Stage drive circuit 17 Stage drive control circuit 18 Pattern data disk 20 Data transfer circuit 21 Irradiation time calculation circuit 22 Other correction circuit 23a Beam figure division processing circuit 24 Sorting processing circuit 40 Proximity effect correction circuit 41 Storage energy ratio calculation circuit 42 Correction value calculation circuit 60 Resize processing circuit 61 Memory

Claims (8)

Drawing a predetermined pattern on the drawing material using a charged particle beam, dividing the drawing area, calculating the proximity effect correction amount in the area from the ratio of the drawing pattern included in the divided area, In a charged particle beam drawing method in which a charged particle beam is shot in consideration of the correction amount and a desired pattern is drawn,
The drawing pattern included in the divided area is divided into shot units,
About the drawing unit for the shot unit Resize processing is performed with a resize value determined in advance according to the size of the drawing unit for the shot unit,
A proximity effect correction amount calculating step for calculating a proximity effect correction amount based on the resized drawing pattern for each shot unit;
While controlling the shot time of the charged particle beam based on the correction amount from the proximity effect correction amount calculation step,
A drawing step of drawing a desired pattern by controlling the size and position of the charged particle beam based on the resized shot-by-shot drawing pattern;
A charged particle beam drawing method comprising: The drawing step includes
While controlling the shot time of the charged particle beam based on the correction value from the proximity effect correction amount calculation step,
Based on the drawing pattern of the shot unit in the proximity effect correction amount calculating step, the charged particle beam of the charged particle beam based on the drawing pattern of the shot unit resized by the resize value determined in advance according to the size of the drawing pattern of the shot unit based on the drawing pattern of the shot unit. The charged particle beam drawing method according to claim 1, wherein a desired pattern is drawn by controlling a size and a position.   The resizing value is a difference between a pattern size actually finished and a designed pattern size by baking, developing, or etching a drawing material on which a desired pattern is drawn using a charged particle beam. The charged particle beam drawing method according to claim 1, wherein:   3. The charge according to claim 1, wherein the resize value has a resize value in the X direction and a resize value in the Y direction, and is a value corresponding to a size of the drawn pattern in the X direction and the Y direction. Particle beam drawing method.   3. The charged particle beam drawing method according to claim 1, wherein the resize value is stored in a memory in advance. A charged particle beam drawing apparatus for drawing a predetermined pattern on a drawing material using a charged particle beam,
Charged particle beam generating means for generating a charged particle beam;
Blanking means for turning on / off irradiation of the charged particle beam from the charged particle beam generating means;
Beam shaping deflection means for forming the charged particle beam into a shaped beam;
Beam positioning deflection means for adjusting the shaped beam to a desired position on the drawing material;
Divide the drawing area,
In a charged particle beam drawing apparatus comprising a proximity effect correction amount calculating means for calculating a proximity effect correction amount in the region from a ratio of a drawing pattern included in the divided region,
The proximity effect correction amount calculating means includes:
A drawing pattern dividing means for dividing a drawing pattern included in the divided area into drawing patterns for each shot;
Resize processing means for resizing with a resize value determined in advance according to the size of the drawing pattern of the shot unit;
The shot time of the charged particle beam is controlled by the blanking unit based on the correction amount calculated by the proximity effect correction amount calculation unit based on the resized shot unit drawing pattern, and based on the resized shot unit drawing pattern. The charged particle beam drawing apparatus, wherein the shaping deflection means controls the size of the charged particle beam, and the beam positioning deflector means controls the position of the charged particle beam. Based on the drawing pattern in shot units from the drawing pattern dividing means of the proximity effect correction amount calculating means, resizing processing means for resizing with a resize value determined in advance according to the size of the drawing pattern is the shaping deflection means. Prepare for the side,
Based on the correction amount calculated by the proximity effect correction amount calculation means, the shot time of the charged particle beam is controlled by the blanking means,
7. The charging according to claim 6, wherein a size of the charged particle beam is controlled by the shaping deflection unit based on an output from the resizing processing unit, and a position of the charged particle beam is controlled by the beam positioning deflection unit. Particle beam drawing device.   The charged particle beam drawing apparatus according to claim 6, wherein the resizing processing unit is connected to a memory.

Images