JP5079408B2 - Charged particle beam drawing apparatus and charged particle beam drawing method - Google Patents

Description

  The present invention relates to a charged particle beam drawing apparatus and a charged particle beam drawing method, for example, charged particle beam drawing for correcting pattern dimension fluctuations caused by the influence of development processing for supplying a developing solution while rotating a sample after drawing. The present invention relates to an apparatus and a method.

  Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is an extremely important process for generating a pattern among semiconductor manufacturing processes. In recent years, with the high integration of LSI, circuit line widths required for semiconductor devices have been reduced year by year. In order to form a desired circuit pattern on these semiconductor devices, a highly accurate original pattern (also referred to as a reticle or a mask) is required. Here, the electron beam (electron beam) drawing technique has an essentially excellent resolution, and is used for producing a high-precision original pattern.

FIG. 10 is a conceptual diagram for explaining the operation of the variable shaping type electron beam drawing apparatus.
The variable shaped electron beam (EB) drawing apparatus operates as follows. First, the first aperture 410 is formed with a rectangular opening 411 for forming the electron beam 330. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 that has passed through the opening 411 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 is deflected by a deflector. And it passes through a part of variable shaping | molding opening 421, and is irradiated to the sample mounted on the stage. The stage continuously moves in a predetermined direction (for example, the X direction) during drawing. Thus, a rectangular shape that can pass through both the opening 411 and the variable shaping opening 421 is drawn in the drawing region of the sample 340. A method of creating an arbitrary shape by passing both the opening 411 and the variable forming opening 421 is referred to as a variable forming method.

First, a predetermined pattern is drawn using an electron beam on a mask substrate coated with a resist material. The drawn mask substrate is then developed by a developing device.
FIG. 11 is a diagram illustrating an example of the developing device.
In the developing device, for example, the developing is performed by ejecting the developer 506 from the upper irradiation port 504 onto the surface of the mask substrate 501 disposed on the rotating table 502. In this development process, the dimensional variation of the resist pattern after development is a problem.

  For example, when an electron beam is irradiated onto a sample such as a mask coated with a resist film, there are factors that cause the resist pattern dimensions to fluctuate, such as proximity effects and fog. The proximity effect is a phenomenon in which irradiated electrons are reflected by the mask and re-irradiate the resist, and the affected range is about a dozen μm. On the other hand, fogging is a resist irradiation phenomenon by multiple scattering in which backscattered electrons due to the proximity effect jump out of the resist, scatter again on the lower surface of the electron column, and irradiate the mask again. cm). Both the proximity effect and the fogging are phenomena in which the resist is re-irradiated, and conventionally, a correction method for correcting such a factor has been studied (for example, see Non-Patent Document 1).

  Here, in the conventional proximity effect and fog correction method, an evaluation board on which representative figures having the same area and center of gravity are appropriately arranged is used. Then, the pattern size of a desired region is measured using the representative figure as a peripheral pattern, and a correction coefficient for correcting the proximity effect and fog is obtained from the result. Then, using the obtained correction coefficient as a fixed value, the beam irradiation amount for correcting the proximity effect and the fog in the pattern actually drawn is calculated.

However, when the resist pattern after development is measured, there is a problem in that the amount of dimensional variation may differ depending on the pattern to be measured even though the peripheral pattern is arranged in the same positional relationship. . Conventionally, the amount of variation was, for example, about 1 nm and could be ignored because it was within an allowable error range. However, the CD accuracy required in the future with the recent miniaturization of patterns becomes 2 nm or less. This variation of 1 nm can no longer be ignored. For this reason, it has been difficult to perform dimensional correction with high accuracy simply by performing the conventional proximity effect and fog correction calculation.
T.A. Abe, S .; Yamazaki, R .; Yoshikawa and T. Takagawa, J. et al. Vac. Sci. Technol. B9 (1991) 3059

  With the recent miniaturization of patterns, the dimensional variation of the resist pattern after development as described above has become a problem. In particular, it has been difficult to perform highly accurate dimensional correction by performing the conventional proximity effect and fog correction calculation.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a drawing apparatus and method that can overcome such problems and correct dimensional variations of a resist pattern after development with higher accuracy.

A charged particle beam drawing apparatus according to one embodiment of the present invention includes:
A pattern density calculation unit for calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
A storage unit for storing a plurality of correction coefficients for correcting a dimensional variation of a pattern caused by a flow of a developing solution and a pattern arrangement positional relationship at the time of development processing performed after drawing;
An acquisition unit for acquiring any correction coefficient for each small area from the storage unit;
A dose calculation unit that calculates a dose of a charged particle beam for each small region using the acquired correction coefficient,
A drawing unit that irradiates a sample with a charged particle beam with a calculated irradiation amount and draws a predetermined pattern on the sample;
It is provided with.

  Here, as will be described later, the inventors have found that the flow of the developer during the development process performed after drawing and the positional relationship of the drawn pattern affect the dimensional variation of the resist pattern after development. I found it. Therefore, a plurality of correction coefficients for correcting the dimensional variation of the pattern due to these influencing factors are obtained in advance. Then, any correction coefficient for correcting the dimensional variation of the pattern due to the influential factor of the corresponding condition is acquired from the layout of the pattern to be actually drawn. Then, the irradiation amount of the charged particle beam is calculated using the correction coefficient.

  As the above-described correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the small area and the peripheral pattern information of the small area is preferably used.

  The positional relationship between the center position of the sample and the small area preferably includes the position of the small area from the center position of the sample and the direction of the small area.

  The small area peripheral pattern information preferably includes the position of the center of gravity of the peripheral pattern based on the position of the small area, the direction of the peripheral pattern, and the area of the peripheral pattern.

The charged particle beam drawing method of one embodiment of the present invention includes:
A step of calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
One correction coefficient is acquired for each small area from a storage device that stores a plurality of correction coefficients for correcting pattern dimensional variations caused by the flow of developer and the pattern arrangement position relationship during development processing performed after drawing. And a process of
A step of calculating the irradiation amount of the charged particle beam for each small region using the obtained correction coefficient;
Irradiating the sample with a charged particle beam with the calculated irradiation amount and drawing a predetermined pattern on the sample; and
Equipped with a,
As the correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the first small area and the peripheral pattern information of the first small area is used,
The peripheral pattern information of the small area includes a gravity center position of the peripheral pattern based on the position of the small area, a direction of the peripheral pattern, and an area of the peripheral pattern .

Moreover, the charged particle beam drawing apparatus according to another aspect of the present invention includes:
A pattern density calculation unit that calculates a pattern density for each first small region of the plurality of first small regions obtained by virtually dividing the drawing region of the sample into a mesh shape;
A storage unit that stores correlation information between a positional relationship between the center position of the sample and the first small region, peripheral pattern information of the first small region, and a fog correction coefficient;
The correlation information is read from the storage unit, and for each second small area larger than the first small area including the first small area, the center position of the sample and the first small area in the second small area An acquisition unit that acquires a corresponding fog correction coefficient based on the relationship between
A calculation unit that calculates the irradiation amount of the charged particle beam for each first small region using the obtained fog correction coefficient;
A drawing unit that irradiates a sample with a charged particle beam with a calculated irradiation amount and draws a predetermined pattern on the sample;
It is provided with.

  Further, as the center position of the sample, it is preferable to use the rotation center position in the development processing in which the developer is supplied while rotating the sample after drawing.

  As described above, even in such a case, the positional relationship between the center position of the sample and the first small area includes the position of the first small area and the direction of the first small area from the center position of the sample. Is preferably included. The peripheral pattern information of the first small area preferably includes the position of the center of gravity of the peripheral pattern based on the position of the first small area, the direction of the peripheral pattern, and the area of the peripheral pattern.

  According to the present invention, it is possible to correct pattern dimensional variations caused by the flow of developer and the pattern arrangement positional relationship during development processing performed after drawing. As a result, the dimensional variation of the resist pattern after development can be corrected with higher accuracy.

  Hereinafter, in the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to an electron beam, and may be a beam using other charged particles such as an ion beam.

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the first embodiment.
In FIG. 1, the drawing apparatus 100 includes a drawing unit 150 and a control unit 160. The drawing apparatus 100 is an example of a charged particle beam drawing apparatus. The drawing apparatus 100 draws a desired pattern on the sample 101. The drawing unit 150 includes an electron column 102 and a drawing chamber 103. In the electron column 102, an electron gun 201, an illumination lens 202, a blanking (BLK) deflector 212, a blanking (BLK) aperture 214, a first aperture 203, a projection lens 204, a deflector 205, a second An aperture 206, an objective lens 207, and a deflector 208 are arranged. In the drawing chamber 103, an XY stage 105 is arranged so as to be movable. A sample 101 is disposed on the XY stage 105. Examples of the sample 101 include an exposure mask substrate that transfers a pattern onto a wafer. The mask substrate includes mask blanks on which nothing is drawn yet. The control unit 160 includes magnetic disk devices 109 and 140, a deflection control circuit 110, a control computer 120, and a memory 121. In the control computer 120, each of a pattern density calculation unit 122 for fog correction, an acquisition unit 124, an irradiation amount calculation unit 126, an irradiation time calculation unit 128, a proximity effect pattern density calculation unit 130, and a drawing data processing unit 132. It has a function. Drawing data stored in the magnetic disk device 109 is input to the control computer 120. In the magnetic disk device 140, a correlation table 142 (correlation) of the positional relationship between the center position of the sample 101 and the fogging mesh area (first small area), the peripheral pattern information of the fogging mesh area, and the fogging correction coefficient. Related information). Information input to the control computer 120 or information during and after the arithmetic processing is stored in the memory 121 each time. Here, a pattern that gives (introduces) a fogging effect or a development flow effect (development loading) is defined as a peripheral pattern.

  A memory 121, a deflection control circuit 110, and magnetic disk devices 109 and 140 are connected to the control computer 120 via a bus (not shown). The deflection control circuit 110 is connected to the BLK deflector 212.

  In FIG. 1, constituent parts necessary for explaining the first embodiment are described. It goes without saying that the drawing apparatus 100 usually includes other necessary configurations. In FIG. 1, a control computer 120, which is an example of a computer, uses a pattern density calculation unit 122 for fog correction, an acquisition unit 124, an irradiation amount calculation unit 126, an irradiation time calculation unit 128, and a proximity effect pattern density calculation unit. Although the processing of each function such as 130 and the drawing data processing unit 132 is described, the present invention is not limited to this. For example, it may be implemented by hardware using an electric circuit. Or you may make it implement by the combination of the hardware and software by an electrical circuit. Alternatively, a combination of such hardware and firmware may be used.

  An electron beam 200 is emitted from an electron gun 201 which is an example of an irradiation unit. The electron beam 200 emitted from the electron gun 201 illuminates the entire first aperture 203 having a rectangular hole, for example, a rectangular hole, by the illumination lens 202. Here, the electron beam 200 is first formed into a rectangle, for example, a rectangle. Then, the electron beam 200 of the first aperture image that has passed through the first aperture 203 is projected onto the second aperture 206 by the projection lens 204. The position of the first aperture image on the second aperture 206 is deflection-controlled by the deflector 205, and the beam shape and size can be changed. As a result, the electron beam 200 is shaped. Then, the electron beam 200 of the second aperture image that has passed through the second aperture 206 is focused by the objective lens 207 and deflected by the deflector 208. As a result, the desired position of the sample 101 on the continuously moving XY stage 105 is irradiated.

  Here, when the electron beam 200 on the sample 101 reaches the irradiation time t in which a desired irradiation amount is incident on the sample 101, blanking is performed as follows. That is, in order to prevent the sample 101 from being irradiated with the electron beam 200 more than necessary, for example, the electron beam 200 is deflected by the electrostatic BLK deflector 212 and the electron beam 200 is cut by the BLK aperture 214. This prevents the electron beam 200 from reaching the surface of the sample 101. The deflection voltage of the BLK deflector 212 is controlled by the deflection control circuit 110 and an amplifier (not shown).

  When the beam is ON (blanking OFF), the electron beam 200 emitted from the electron gun 201 follows the trajectory indicated by the solid line in FIG. On the other hand, in the case of beam OFF (blanking ON), the electron beam 200 emitted from the electron gun 201 follows the trajectory indicated by the dotted line in FIG. In addition, the inside of the electron column 102 and the drawing chamber 103 are evacuated by a vacuum pump (not shown) to form a vacuum atmosphere in which the pressure is lower than the atmospheric pressure.

  Here, the inventor has found that the flow of the developer during the development process performed after drawing and the positional relationship of the drawn pattern affect the dimensional variation of the resist pattern after development. Therefore, the fog correction coefficient θ used when calculating the exposure dose corrected for the proximity effect and fog is correlated with these influencing factors to correct pattern variation due to these influencing factors. The above-mentioned problem was solved by using a correction coefficient. The dose D (x) corrected for the proximity effect and the fog can be obtained by the following equations (1-1) to (1-3).

Where η is the proximity effect correction coefficient, σ _p is the proximity effect influence range, θ is the above fog correction coefficient, σ _f is the fog effect influence range, K is the normalization coefficient, and D (x) is the above-described irradiation dose (Dose). ). Here, (x, y) = (x).

  First, a method for obtaining this correlation will be described below. In the first embodiment, as the developing method, the above-described correlation in the case where the developing solution is supplied onto the substrate that rotates with the substrate center as the rotation axis as described in FIG. 11 is obtained. In this case, the developer flows in the radial direction from the center of the substrate toward the outside by centrifugal force. Therefore, create a plurality of evaluation substrates with different positional relations between the figure to be measured and the peripheral patterns located in the periphery, and the size of the peripheral patterns, and how the developer flows and the positional relationship between the drawn patterns The correlation with the fog correction coefficient θ is obtained.

FIG. 2 is a diagram showing an example of the first evaluation board in the first embodiment.
In FIG. 2, a figure 30 to be a peripheral pattern and a pattern 20 to be measured are drawn on a mask substrate 10. Here, the flow direction of the developing solution flows in the radial direction from the center of the substrate toward the outside, so that the influence is a rotation target. Therefore, it is sufficient to measure the evaluation substrate in one of the four regions divided in the x and y directions passing through the center of the mask substrate 10, for example, the first quadrant as shown in FIG. Therefore, in FIG. 2, an evaluation substrate is manufactured in which the figure 30 is arranged at the center of the mask substrate 10 and the patterns 20 are arranged at a predetermined pitch, for example, 1 mm pitch in the first quadrant. At this time, as the pattern 20, for example, a line-and-space pattern to be drawn with an irradiation amount obtained by changing the fog correction coefficient θ into four θ _a to θ _d in _a 1 mm square region is arranged. For example, it is preferable to arrange with a line width and a space of 1 μm. Further, a similar evaluation substrate is manufactured by arranging a graphic 31 larger than the graphic 30 at the same position on another mask substrate 10. Similarly, a similar evaluation substrate is produced by arranging a graphic 32 larger than the graphic 31 at the same position on another mask substrate 10. Similarly, a similar evaluation substrate is produced by arranging a graphic 33 larger than the graphic 32 at the same position on another mask substrate 10. For example, the figure 30 is drawn with a 15 mm square, the figure 31 with a 30 mm square, the figure 32 with a 45 mm square, and the figure 33 with a 60 mm square. In this way, four evaluation substrates are prepared in which peripheral patterns having different sizes are arranged at the same position.

FIG. 3 is a diagram showing an example of the second evaluation board in the first embodiment.
In FIG. 3, a figure 40 to be a peripheral pattern and a pattern 20 to be measured are drawn on the mask substrate 10. This time, the figure 40 is arranged in the vicinity of one stroke located in the first quadrant of the four corners of the mask substrate 10, that is, in a position moved in the x and y directions, and the pattern 20 is placed at a predetermined pitch in the first quadrant area. For example, an evaluation board to be laid and arranged at a pitch of 1 mm is produced. The pattern 20 is the same as in the case of FIG. Here, for example, the figure 40 is drawn with a 15 mm square, the figure 41 with a 30 mm square, the figure 42 with a 45 mm square, and the figure 43 with a 60 mm square. In this way, four evaluation substrates are prepared in which peripheral patterns having different sizes are arranged at the same position.

FIG. 4 is a diagram showing an example of the third evaluation board in the first embodiment.
In FIG. 4, a figure 50 to be a peripheral pattern and a pattern 20 to be measured are drawn on the mask substrate 10. This time, the figure 50 is arranged in the vicinity of the position where the figure 50 is moved from the center of the mask substrate 10 to the end in the x direction, and the pattern 20 is arranged in a first quadrant area with a predetermined pitch, for example, 1 mm pitch. A substrate is produced. The pattern 20 is the same as in the case of FIG. Here, for example, the figure 50 is drawn with a 15 mm square, the figure 51 with a 30 mm square, the figure 52 with a 45 mm square, and the figure 53 with a 60 mm square. In this way, four evaluation substrates are prepared in which peripheral patterns having different sizes are arranged at the same position.

FIG. 5 is a diagram illustrating an example of a fourth evaluation board in the first embodiment.
In FIG. 5, a figure 60 to be a peripheral pattern and a pattern 20 to be measured are drawn on the mask substrate 10. This time, the figure 60 is arranged in the vicinity of the position where the figure 60 is moved from the center of the mask substrate 10 to the end in the y direction, and the pattern 20 is arranged in the first quadrant with a predetermined pitch, for example, 1 mm pitch. A substrate is produced. The pattern 20 is the same as in the case of FIG. Here, for example, the figure 60 is drawn with a 15 mm square, the figure 61 is drawn with a 30 mm square, the figure 62 is drawn with a 45 mm square, and the figure 63 is drawn with a 60 mm square. In this way, four evaluation substrates are prepared in which peripheral patterns having different sizes are arranged at the same position.

  As described above, 4 × 4 = 16 types of evaluation substrates are produced. Then, each pattern dimension in the pattern 20 is measured. Then, an error from the design dimension is measured. Here, in FIGS. 2, 3, 4 and 5, since the positional (distance) relationship between the peripheral pattern and the measurement pattern is the same, the influence of the fogging is the same.

FIG. 6 is a diagram illustrating an example of a correlation table in the first embodiment.
Based on the results obtained from the 16 types of evaluation boards, a correlation table 142 as shown in FIG. 16 is created. Here, the flow of the developer and the arrangement positional relationship of the drawn pattern are defined by the positional relationship between the center position of the evaluation substrate and the fog correction mesh and the peripheral pattern information of the fog correction mesh. Specifically, the positional relationship between the center position of the substrate and the fog correction mesh is determined by the position (x, y) of the fog correction mesh from the center position of the substrate and the direction (v) of the fog correction mesh. Define. The peripheral pattern information of the fog correction mesh includes the barycentric position (X, Y) of the peripheral pattern with respect to the position of the fog correction mesh, the direction (v ′) of the peripheral pattern, and the area (S) of the peripheral pattern. And defined by The correlation table 142 is created by associating these factors with the fog correction coefficient θ. Since four types of fog correction coefficients θ _{a to} θ _d are used in the evaluation pattern, an optimal value among them may be selected. Alternatively, it is preferable to determine the optimum θ by interpolation. The correlation table 142 obtained as described above is stored in the magnetic disk device 140.

As described above, after obtaining the correlation table 142, the drawing apparatus 100 draws a desired pattern on the sample 101.
FIG. 7 is a flowchart showing main steps of the drawing method according to the first embodiment.
First, the control computer 120 reads drawing data from the magnetic disk device 109. Then, the drawing data is converted into data in the apparatus format by the drawing data processing unit 132. In addition to the conversion process, dose calculation is performed in the following steps.

In S (step) 102, as a fog density correction pattern calculation process, the fog correction pattern density calculation unit 122 corrects a drawing area of the sample 101 to be drawn with a plurality of mesh-shaped fog corrections with a predetermined grid size. Virtually dividing into mesh areas (first small areas). The size (mesh size) of the fog correction mesh region is preferably set to, for example, 1/10 or less of the fogging effect influence range σ _f . For example, when the influence range σ _f is several tens of mm, it is preferable that the range is about 500 μm to 1 mm. Then, the pattern density calculation unit 122 calculates the pattern density V for each fog correction mesh region based on the drawing data. The pattern density V can be obtained by the above equation (1-2).

In step S104, as a pattern density calculation process for proximity effect correction, the pattern density calculation unit 130 for proximity effect correction uses a plurality of proximity effect correction meshes in a mesh shape with a predetermined grid size for the drawing region of the sample 101 to be drawn. Virtually divide into areas (small areas). The size of the proximity effect correction mesh region (mesh size), it is preferable to set the example to 1/10 or less proximity effect influence range sigma _p. For example, when the influence range σ _p is several tens of μm, it is preferable that the range is 1 μm or less. Then, the pattern density calculation unit 130 calculates the pattern density U for each proximity effect correction mesh region based on the drawing data. The pattern density U can be obtained by the above equation (1-1).

In S106, as the fogging effect correction coefficient θ acquisition step, the acquisition unit 124 acquires any correction coefficient for each fog correction mesh region from the magnetic disk device 140 (storage unit). Specifically, first, the fog correction mesh region is obtained for each region (second small region) in which the acquisition unit 124 combines a plurality of developer flow influence ranges σ _d larger than the fog correction mesh region including the fog correction mesh region. The position of the center of gravity of the peripheral pattern, the direction of the peripheral pattern, and the area of the peripheral pattern are obtained. Further, the acquisition unit 124 obtains the position (x, y) of the fog correction mesh region from the center position O of the sample 101 and the direction (v) of the fog correction mesh region.

FIG. 8 is a diagram for explaining a method for obtaining an influencing factor in the first embodiment.
In FIG. 8, the sample 101 is virtually divided into a plurality of mesh-like developer flow mesh regions 74 having a developer flow influence range σ _d as a grid size. The size (mesh size) of the developer flow mesh region 74 varies depending on the parameters of the developing device and the development process, but is preferably set to about several mm to several cm, for example. The sample 101 is also virtually divided into a plurality of fog correction mesh regions 72 smaller than the developer flow mesh region 74. Then, the periphery in nine developer flow mesh regions 74 composed of the developer flow mesh region 74 including the fog correction mesh region 70 where the pattern to be drawn is located and the developer flow mesh region 74 surrounding the periphery thereof. Synthesize the pattern. By adding to the surrounding area, the influence of the developer flow can be sufficiently included.

FIG. 9 is another diagram for explaining a method for obtaining an influence factor in the first embodiment.
After the synthesis, as shown in FIG. 9, the position (X, Y) of the center of gravity G of the synthesized peripheral pattern 80 based on the position of the fog correction mesh region 70 and the direction of the synthesized peripheral pattern 80 (v ′ ) And the area S of the synthesized peripheral pattern 80. Further, the position (x, y) of the fog correction mesh region 70 from the center position O of the sample 101 and the direction (v) of the fog correction mesh region 70 are obtained. As described above, since the influence factors of the correlation table 142 can be obtained, the acquisition unit 124 reads the correlation table 142 from the magnetic disk device 140 and acquires the corresponding fog correction coefficient θ based on the obtained influence factors. To do. Even when there is no completely matching condition, the fog correction coefficient θ of the closest condition may be acquired.

  In S108, as the dose calculation step, the dose calculation unit 126 calculates the dose D (x) of the electron beam 200 to be irradiated on the fog correction mesh region 70 using the acquired fog correction coefficient. This calculation is performed for each fog correction mesh region 72 to be drawn.

  In S110, as the irradiation time calculation step, the irradiation time calculation unit 128 uses the obtained irradiation dose D (x) and the set current density J for each fog correction mesh region 72, and the irradiation time t (= The dose D (x) / current density J) is calculated.

  In S112, as a drawing process, the control computer 120 outputs a signal to the deflection control circuit 110 so that the beam irradiation to the sample 101 is turned off at the obtained irradiation time t. Then, the deflection control circuit 110 controls the BLK deflector 212 so as to deflect the electron beam 200 in accordance with the obtained irradiation time t along the signal. Then, after irradiating the sample 101 with a desired dose D (x), the electron beam 200 deflected by the BLK deflector 212 is shielded by the BLK aperture 214 so as not to reach the sample 101. In this manner, the drawing unit 150 draws a predetermined pattern on the sample 101 by irradiating the sample 101 with the electron beam 200 with the calculated dose D (x).

  As described above, in the first embodiment, a plurality of fog correction coefficients θ for correcting the pattern dimensional variation caused by these influencing factors described above are obtained in advance. Then, one of the fog correction coefficients θ for correcting the dimensional variation of the pattern caused by the corresponding influence factor under substantially the same condition is acquired from the layout of the pattern to be actually drawn. Then, the irradiation amount D (x) of the electron beam 200 is calculated using the fog correction coefficient θ. With such a configuration, it is possible to correct pattern dimensional variations caused by the flow of the developer and the pattern arrangement positional relationship during the development processing performed after drawing. As a result, the dimensional variation of the resist pattern after development can be corrected with higher accuracy.

  In the above description, the processing content or operation content described as “˜part” or “˜process” can be configured by a program operable by a computer. Or you may make it implement by not only the program used as software but the combination of hardware and software. Alternatively, a combination with firmware may be used. When configured by a program, the program is recorded on a recording medium such as a magnetic disk device, a magnetic tape device, an FD, or a ROM (Read Only Memory). For example, it is recorded on the magnetic disk device 140.

  Further, the control computer 120 serving as a computer further includes a random access memory (RAM), a ROM, a magnetic disk (HD) device, which are examples of storage devices, and a keyboard, which is an example of input means, via a bus (not shown). (K / B), a mouse, a monitor as an example of an output unit, a printer, or an external interface (I / F) as an example of an input / output unit, an FD, a DVD, a CD, or the like.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, although 16 types of evaluation boards are prepared, the invention is not limited to this, and it may be small or large. Further, the arrangement positions of the peripheral patterns may be evaluated at different positions.

  In addition, although descriptions are omitted for parts and the like that are not directly required for the description of the present invention, such as a device configuration and a control method, a required device configuration and a control method can be appropriately selected and used. For example, although the description of the control unit configuration for controlling the drawing apparatus 100 is omitted, it goes without saying that the required control unit configuration is appropriately selected and used.

  In addition, all charged particle beam writing methods and apparatuses that include elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention.

1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. FIG. 3 is a diagram showing an example of a first evaluation board in the first embodiment. FIG. 3 is a diagram showing an example of a second evaluation board in the first embodiment. FIG. 10 is a diagram showing an example of a third evaluation board in the first embodiment. FIG. 10 is a diagram showing an example of a fourth evaluation board in the first embodiment. 6 is a diagram illustrating an example of a correlation table in the first embodiment. FIG. FIG. 4 is a flowchart showing main steps of the drawing method according to Embodiment 1. 6 is a diagram for explaining a method for obtaining an influence factor in the first embodiment. FIG. FIG. 11 is another diagram for explaining a method for obtaining an influence factor in the first embodiment. It is a conceptual diagram for demonstrating operation | movement of the conventional variable shaping type | mold electron beam drawing apparatus. It is a figure which shows an example of a developing device.

Explanation of symbols

10,501 Mask substrate 20 Pattern 30, 31, 32, 33, 40, 41, 42, 43 Graphic 50, 51, 52, 53, 60, 61, 62, 63 Graphic 70, 72 Fog correction mesh area 74 Developer flow Mesh area 80 Peripheral pattern 100 Drawing device 101, 340 Sample 102 Electron barrel 103 Drawing chamber 105 XY stage 109, 140 Magnetic disk device 110 Deflection control circuit 120 Control computer 121 Memory 122, 130 Pattern density calculation unit 124 Acquisition unit 126 Irradiation amount Calculation unit 128 Irradiation time calculation unit 132 Drawing data processing unit 142 Correlation table 150 Drawing unit 160 Control unit 200 Electron beam 201 Electron gun 202 Illumination lenses 203 and 410 First aperture 204 Projection lenses 205 and 208 Deflectors 206 and 420 Second Aperture 07 objective lens 212 BLK deflector 214 BLK aperture 330 electron beam 411 opening 421 variable-shaped opening 430 a charged particle source 502 table 504 irradiation port 506 developer

Claims (4)

A pattern density calculation unit for calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
A storage unit for storing a plurality of correction coefficients for correcting a dimensional variation of a pattern caused by a flow of a developing solution and a pattern arrangement positional relationship at the time of development processing performed after drawing;
An acquisition unit that acquires any of the correction coefficients for each of the small regions from the storage unit;
A dose calculation unit that calculates a dose of a charged particle beam for each small region using the acquired correction coefficient,
A drawing unit for irradiating the sample with a charged particle beam at a calculated irradiation amount and drawing a predetermined pattern on the sample;
Equipped with a,
As the correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the first small area and the peripheral pattern information of the first small area is used,
The charged particle beam drawing apparatus characterized in that the peripheral pattern information of the small region includes the position of the center of gravity of the peripheral pattern based on the position of the small region, the direction of the peripheral pattern, and the area of the peripheral pattern . A pattern density calculation unit for calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
A storage unit for storing a plurality of correction coefficients for correcting a dimensional variation of a pattern caused by a flow of a developing solution and a pattern arrangement positional relationship at the time of development processing performed after drawing;
An acquisition unit that acquires any of the correction coefficients for each of the small regions from the storage unit;
A dose calculation unit that calculates a dose of a charged particle beam for each small region using the acquired correction coefficient,
A drawing unit for irradiating the sample with a charged particle beam at a calculated irradiation amount and drawing a predetermined pattern on the sample;
Equipped with a,
As the correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the first small area and the peripheral pattern information of the first small area is used,
The positional relationship between the center position of the sample and the small area includes the position of the small area from the center position of the sample and the direction of the small area,
The charged particle beam drawing apparatus characterized in that the peripheral pattern information of the small region includes the position of the center of gravity of the peripheral pattern based on the position of the small region, the direction of the peripheral pattern, and the area of the peripheral pattern . A step of calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
Any one of the correction coefficients for each of the small areas from a storage device that stores a plurality of correction coefficients for correcting the dimensional variation of the pattern due to the flow of the developing solution and the pattern arrangement position relationship during the development processing performed after drawing. A process of obtaining
Using the acquired correction coefficient, calculating a dose of a charged particle beam for each of the small regions;
Irradiating the sample with a charged particle beam at the calculated irradiation amount and drawing a predetermined pattern on the sample; and
Equipped with a,
As the correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the first small area and the peripheral pattern information of the first small area is used,
The charged particle beam drawing method characterized in that the peripheral pattern information of the small region includes the position of the center of gravity of the peripheral pattern based on the position of the small region, the direction of the peripheral pattern, and the area of the peripheral pattern . A step of calculating a pattern density for each of a plurality of small areas obtained by virtually dividing a drawing area of a sample into a mesh shape;
Any one of the correction coefficients for each of the small areas from a storage device that stores a plurality of correction coefficients for correcting the dimensional variation of the pattern due to the flow of the developing solution and the pattern arrangement position relationship during the development processing performed after drawing. A process of obtaining
Using the acquired correction coefficient, calculating a dose of a charged particle beam for each of the small regions;
Irradiating the sample with a charged particle beam at the calculated irradiation amount and drawing a predetermined pattern on the sample; and
Equipped with a,
As the correction coefficient, a fog correction coefficient corresponding to the positional relationship between the center position of the sample and the first small area and the peripheral pattern information of the first small area is used,
The positional relationship between the center position of the sample and the small area includes the position of the small area from the center position of the sample and the direction of the small area,
The charged particle beam drawing method characterized in that the peripheral pattern information of the small region includes the position of the center of gravity of the peripheral pattern based on the position of the small region, the direction of the peripheral pattern, and the area of the peripheral pattern .

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