JP2012069667A - Charged particle beam drawing device and drawing method of charged particle beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drawing device capable of correcting a dimensional variation which cannot be completely assumed in a fogging effect model together.SOLUTION: A charged particle beam drawing device comprises: a fogging effect correction coefficient acquisition part 26 which acquires a fogging effect correction coefficient in which a pattern size after fogging effect correction matches proximity effect correction; a residual fogging effect correction amount acquisition part 24 which acquires a residual fogging effect correction amount when the fogging effect is corrected; a reference irradiation amount calculation part 16 which calculates a reference irradiation amount when the residual fogging effect correction amount is corrected together with a proximity effect; a proximity effect correction coefficient calculation part 17 which calculates the proximity effect correction coefficient which corrects the residual fogging effect correction amount together with the proximity effect; a fogging effect correction irradiation coefficient calculation part 20 which calculates a fogging effect correction irradiation coefficient using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient; an irradiation amount calculation part 34 which calculates a beam irradiation amount using the fogging effect correction irradiation coefficient; and a drawing part 150 which draws a pattern on a sample based on the irradiation amount.

Description

  The present invention relates to a charged particle beam drawing apparatus and a charged particle beam drawing method, and for example, relates to an apparatus and method for correcting a fogging effect with an irradiation amount.

  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. 15 is a conceptual diagram for explaining the operation of a conventional variable shaping type electron beam drawing apparatus.
The variable shaped electron beam (EB) drawing apparatus operates as follows. In the first aperture 410, a rectangular opening for forming the electron beam 330, for example, a rectangular opening 411 is formed. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 having passed through the opening 411 of the first aperture 410 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 of the first aperture 410 is deflected by the deflector, passes through a part of the variable shaping opening 421 of the second aperture 420, and passes through a predetermined range. The sample 340 mounted on a stage that continuously moves in one direction (for example, the X direction) is irradiated. That is, the drawing area of the sample 340 mounted on the stage in which the rectangular shape that can pass through both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is continuously moved in the X direction. Drawn on. A method of creating an arbitrary shape by passing both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is referred to as a variable shaping method (VSB method).

  In the above-described electron beam drawing, line width uniformity within a sample surface, for example, a mask surface with higher accuracy is required. Here, in such electron beam drawing, when a circuit pattern is drawn by irradiating a resist-coated mask with an electron beam, the electron beam passes through the resist layer and reaches the layer below it, and then reappears on the resist layer again. A phenomenon called a proximity effect due to incident backscattering occurs. Furthermore, a phenomenon called a fogging effect occurs in a wider range of influence than the proximity effect. As a result, during drawing, a dimensional variation is generated in which drawing is performed with a size shifted from a desired size. On the other hand, even when development or etching after drawing is performed, a dimensional variation called a loading effect due to the density of the circuit pattern occurs.

The electron beam irradiation amount includes, for example, a reference irradiation amount D _base , a proximity effect correction coefficient η for correcting the proximity effect, and a proximity effect correction irradiation coefficient Dp (η, dependent on the pattern area density ρ or the proximity effect density U. ρ) and the product. Here, there is a proximity effect correction coefficient η with which the proximity effect correction matches well for each reference dose D _base . The size of the resist image increases as the reference dose D _base increases.

Therefore, there is a method of correcting the amount of dimensional variation due to the loading effect while changing the set of the reference dose D _base and the proximity effect correction coefficient η for each position of the substrate and maintaining the proximity effect correction (for example, Patent Documents). 1). Regardless of the proximity effect density U, the same dimensional change amount can be obtained with the irradiation amount obtained by this method. That is, the dimension correction is performed so that the proximity effect correction does not shift. Such correction is suitable for correcting the loading effect that occurs during etching of the light shielding film after drawing.

  On the other hand, with regard to dimensional variation due to the fogging effect, which has a wider range of influence than the range of influence of the proximity effect, it is assumed in the conventional fogging effect model in a region where the pattern density is wide, as dimensional accuracy is required. It has been found that errors that are not full occur.

JP 2007-150423 A

  As described above, the conventional method has not been able to correct the dimensional variation that cannot be assumed by the fogging effect model. To solve this problem, the average size of each proximity effect density when drawing in a wide pattern density area and the size when drawing without breaking proximity effect correction in a low area pattern density area It has also been studied to obtain a fog correction coefficient so that the two have the same dimensions. However, this method has a problem that the proximity effect cannot be corrected depending on the proximity effect density. However, a sufficient method for solving such a problem has not been established.

  Therefore, an object of the present invention is to provide a drawing apparatus and method capable of overcoming such problems and correcting dimensional variations that cannot be assumed in the fogging effect model.

A charged particle beam drawing apparatus according to one embodiment of the present invention includes:
A fogging effect correction coefficient acquisition unit that acquires a fogging effect correction coefficient in which the pattern dimensions after the fogging effect correction match regardless of the proximity effect density;
A fog effect correction remaining amount acquisition unit that acquires a correction amount of the fog effect when the fog effect is corrected using the fog effect correction coefficient;
A reference dose calculation unit for calculating a reference dose for correcting the fogging effect correction remaining amount together with a dimensional variation due to the proximity effect;
A proximity effect correction coefficient calculating unit that calculates a proximity effect correction coefficient for correcting the fogging effect correction remaining amount together with the dimensional variation amount due to the proximity effect;
A fogging effect correction irradiation coefficient calculating unit that calculates a fogging effect correction irradiation coefficient that corrects the fogging effect using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient;
A dose calculation unit for calculating the dose of the charged particle beam when drawing using the fogging effect correction irradiation coefficient;
A drawing unit for drawing a pattern on the sample with the above-mentioned irradiation amount;
It is provided with.

  Further, the fogging effect correction coefficient and the remaining fogging effect correction amount are fed back, and the fogging effect correction coefficient and the fogging effect correction coefficient are changed again until the difference between the previous fogging effect correction remaining amount and the current fogging effect correction remaining amount falls within the threshold value. The remaining fogging effect correction amount, the reference irradiation amount, the proximity effect correction coefficient, and the fogging effect correction irradiation coefficient are repeatedly obtained.

Further, it further includes a fogging effect dose amount calculation unit that calculates the fogging effect dose amount caused by the fogging effect using the reference irradiation amount and the proximity effect correction coefficient,
The fogging effect correction coefficient and the remaining fogging effect correction amount are acquired depending on the fogging effect dose.

Further, a first pattern dimension of the first evaluation pattern when the proximity effect, the fogging effect, and the loading effect are corrected with respect to the first evaluation pattern in which another pattern is arranged within the influence range of the fogging effect; The first pattern dimensions of the second evaluation pattern when the proximity effect, the fogging effect, and the loading effect are corrected with respect to the second evaluation pattern in which another pattern is not disposed within the range of influence of the fogging effect. The difference corrects the third pattern size of the first evaluation pattern when the proximity effect and the fogging effect are corrected for the first evaluation pattern, and the proximity effect and the fogging effect for the second evaluation pattern. A storage unit for storing a loading effect correction coefficient set so as to coincide with the second difference between the second evaluation pattern and the fourth pattern dimension at the time,
A dimensional variation calculation unit that calculates an addition value of the dimensional variation due to the loading effect depending on the loading effect correction coefficient and the fogging effect correction remaining amount;
Further comprising
The reference dose calculation unit calculates the reference dose so as to correct the added dimensional variation amount together with the dimensional variation amount due to the proximity effect,
The proximity effect correction coefficient calculation unit calculates the proximity effect correction coefficient so as to correct the added dimensional variation amount together with the dimensional variation amount due to the proximity effect,
The fogging effect dose amount calculation unit calculates the fogging effect dose amount using the reference irradiation amount based on the added dimensional variation amount and the proximity effect correction coefficient,
The fogging effect correction coefficient acquisition unit acquires the fogging effect correction coefficient according to the fogging effect dose amount based on the added dimensional variation amount,
The fogging effect correction remaining amount acquisition unit acquires the fogging effect correction remaining amount according to the fogging effect dose based on the added dimensional variation amount,
The fogging effect correction irradiation coefficient calculation unit calculates the fogging effect correction irradiation coefficient by using a fogging effect correction coefficient, a reference irradiation amount, and a proximity effect correction coefficient based on the dimensional variation added together. .

The charged particle beam drawing method of one embodiment of the present invention includes:
A step of obtaining a fogging effect correction coefficient in which the pattern dimensions after the fogging effect correction match regardless of the proximity effect density;
Obtaining a remaining correction amount of the fogging effect when the fogging effect is corrected using the fogging effect correction coefficient;
A step of calculating a reference irradiation amount for correcting the remaining fogging effect correction amount together with a dimensional variation amount due to the proximity effect;
Calculating a proximity effect correction coefficient for correcting the remaining fogging effect correction amount together with the dimensional variation due to the proximity effect;
Calculating a fogging effect correction irradiation coefficient for correcting the fogging effect using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient;
Calculating the irradiation amount of the charged particle beam when drawing using the fogging effect correction irradiation coefficient;
Drawing a pattern on the sample with a dose, and
It is provided with.

  According to one aspect of the present invention, a dimensional variation that cannot be assumed in the fogging effect model can be corrected without destroying the proximity effect correction. Therefore, it is possible to draw with highly accurate dimensions.

1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. 6 is a diagram showing an example of a relationship between a pattern dimension and a fogging effect correction coefficient in the first embodiment. FIG. FIG. 4 is a flowchart showing main steps of the drawing method according to Embodiment 1. 3 is a diagram showing an example of a pattern layout without a background pattern (NOBKG) in Embodiment 1. FIG. 4 is a graph showing an example of correlation data between a pattern dimension CD and an irradiation amount D in the first embodiment. 4 is a graph showing an example of correlation data between a pattern dimension CD and a proximity effect correction coefficient η in the first embodiment. 6 is a graph showing an example of correlation data of a pattern dimension CD, a proximity effect correction coefficient η, and a reference dose Dbase in the first embodiment. 6 is a diagram showing an example of a pattern layout with a background pattern (BKG) in the first embodiment. FIG. 6 is a diagram showing an example of a relationship between a pattern dimension and a fogging effect correction coefficient in the first embodiment. FIG. FIG. 6 is a diagram showing an example of a correlation between a fogging effect correction coefficient θ0 and a fogging effect dose amount Df in the first embodiment. 6 is a diagram illustrating an example of a fogging effect distribution function according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a correlation between a fogging effect correction remaining amount CDres and a fogging effect dose amount Df in the first embodiment. FIG. 6 is a diagram illustrating an example of a relationship between a pattern dimension and a loading effect correction coefficient in the first embodiment. FIG. 6 is a diagram illustrating an example of a loading effect distribution function in Embodiment 1. FIG. It is a conceptual diagram for demonstrating operation | movement of the conventional variable shaping type | mold electron beam drawing apparatus.

  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 a beam using charged particles such as an ion beam may be used. Further, a variable shaping type drawing apparatus will be described as an example of the charged particle beam apparatus.

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. In particular, it is an example of a variable shaping type (VSB type) drawing apparatus. The drawing unit 150 includes an electron column 102 and a drawing chamber 103. In the electron column 102, there are an electron gun 201, an illumination lens 202, a blanking deflector (blanker) 212, a blanking aperture 214, a first shaping aperture 203, a projection lens 204, a deflector 205, and a second shaping aperture. 206, an objective lens 207, and a deflector 208 are arranged. An XY stage 105 that can move at least in the XY direction is disposed in the drawing chamber 103. On the XY stage 105, a sample 101 to be drawn on which a resist is applied is disposed. The sample 101 includes an exposure mask and a silicon wafer for manufacturing a semiconductor device. Masks include mask blanks.

  The control unit 160 includes control computers 110 and 120, memories 111 and 121, a deflection control circuit 132, a DAC (digital / analog converter) amplifier unit 130 (deflection amplifier), and storage devices 140 and 142 such as a magnetic disk device. ing. The control computers 110 and 120, the memories 111 and 121, the deflection control circuit 132, and the storage devices 140 and 142 such as a magnetic disk device are connected to each other via a bus (not shown). A DAC amplifier unit 130 is connected to the deflection control circuit 132. The DAC amplifier unit 130 is connected to the blanking deflector 212.

  A digital signal for blanking control is output from the deflection control circuit 132 to the DAC amplifier unit 130. The DAC amplifier unit 130 converts the digital signal into an analog signal, amplifies it, and applies it to the blanking deflector 212 as a deflection voltage. The electron beam 200 is deflected by such a deflection voltage, and a beam of each shot is formed.

  Further, in the control computer 110, a pattern area ratio map creation unit 10, a loading amount map creation unit 12, a fogging effect correction remaining amount addition unit 14, a reference irradiation amount map calculation unit 16, a proximity effect correction coefficient map calculation unit 17, Proximity effect correction irradiation coefficient map calculation unit 18, fogging effect correction irradiation coefficient map calculation unit 20, fogging effect dose amount calculation unit 22, fogging effect correction remaining amount calculation unit 24, fogging effect correction coefficient map calculation unit 26, determination unit 28, And the output part 30 is arrange | positioned. Pattern area rate map creation unit 10, loading amount map creation unit 12, fogging effect correction remaining amount addition unit 14, reference dose map calculation unit 16, proximity effect correction coefficient map calculation unit 17, proximity effect correction irradiation coefficient map calculation unit 18 The fogging effect correction irradiation coefficient map calculation unit 20, the fogging effect dose amount calculation unit 22, the fogging effect correction remaining amount calculation unit 24, the fogging effect correction coefficient map calculation unit 26, the determination unit 28, and the output unit 30, It may be configured by software such as a program. Alternatively, it may be configured by hardware such as an electronic circuit. Alternatively, a combination thereof may be used. The input data necessary for the control computer 110 or the calculated result is stored in the memory 111 each time.

  Further, in the control computer 120, a proximity effect correction coefficient map calculation unit 32, an irradiation amount calculation unit 34, an irradiation time calculation unit 36, and a drawing processing control unit 38 are arranged. Each function such as the proximity effect correction coefficient map calculation unit 32, the irradiation amount calculation unit 34, the irradiation time calculation unit 36, and the drawing processing control unit 38 may be configured by software such as a program. Alternatively, it may be configured by hardware such as an electronic circuit. Alternatively, a combination thereof may be used. The input data necessary for the control computer 120 or the calculated result is stored in the memory 121 each time.

  As fogging effect correction parameters, Dfog-CDres correlation information indicating the correlation between the fogging effect dose amount Dfog and the fogging effect correction remaining amount CDres, and the correlation between the fogging effect dose amount Dfog and the fogging effect correction coefficient θ is Dfog−. The θ correlation information and the fogging effect distribution function radius σF are input from the outside and stored in the storage device 140. Further, as the proximity effect correction parameter, ΔCD-Dbase correlation information indicating the correlation between the pattern dimension error ΔCD and the reference dose Dbase, and ΔCD-η indicating the correlation between the pattern dimension error ΔCD and the proximity effect correction coefficient η. The correlation information is input from the outside and further stored in the storage device 140. As loading effect correction parameters, a loading effect correction coefficient γ, a radius σL of the loading effect distribution function, and a loading effect size variation amount CDpos (x) depending on the drawing position are input from the outside, and further stored in the storage device 140. It is remembered. CD-Dbase correlation information and CD-η correlation information also function as loading effect correction parameters. The storage device 142 stores drawing data inputted from the outside.

  Here, FIG. 1 shows a configuration necessary for explaining the first embodiment. The drawing apparatus 100 may normally have other necessary configurations. For example, it goes without saying that each DAC amplifier unit for the deflector 205 and the deflector 208 is also provided.

  FIG. 2 is a diagram showing an example of the relationship between the pattern dimension and the fogging effect correction coefficient in the first embodiment. In FIG. 2, the vertical axis indicates the pattern dimension CD, and the horizontal axis indicates the fogging effect correction coefficient θ. In the example of FIG. 2, the pattern dimension CD is shown when drawing is performed while the fogging effect correction coefficient θ is variable and the fogging effect correction is performed. Here, the evaluation pattern is covered with a solid pattern and drawn with a pattern layout (BKG: with background pattern) in which the range of influence of the fogging effect is substantially 100%. This shows a case where a pattern is not arranged around and the pattern is drawn with a pattern layout (NOBKG: no background pattern) in which the range of influence of the fogging effect is substantially 0% pattern area density. The range of influence of the fogging effect is in the range of several mm to several cm. In order to maintain the proximity effect correction regardless of the proximity effect density, in the pattern layout with the background pattern (BKG), the CD and θ values at the position A where the dimensions do not change depending on the proximity effect density are obtained. With the recent miniaturization of patterns, it has been found that the pattern dimension CD does not coincide with the pattern dimension CD whose dimension does not change due to the proximity effect density in the pattern layout without a background pattern (NOBKG). Here, as a method for obtaining a constant fogging effect correction coefficient θ, an average size of each proximity effect density and a region having a low pattern density in a wide area (BKG) drawn in a region having a large pattern density (BKG). It is conceivable to obtain the fog correction coefficient θ0 so that the dimensions when drawing without breaking the proximity effect correction with NOBKG) are the same. However, with such a fog correction coefficient θ0, a state in which the proximity effect cannot be corrected depending on the proximity effect density occurs in a wide area (BKG) having a high pattern density. Therefore, in the first embodiment, the fogging effect correction is performed while maintaining the proximity effect correction regardless of the proximity effect density, and the remaining fogging correction amount that cannot be corrected by the fogging correction is combined with the dimension variation amount by the loading effect correction. To correct.

  FIG. 3 is a flowchart showing main steps of the drawing method according to the first embodiment. In FIG. 3, as a process performed in advance before inputting to the drawing apparatus 100, a NOBKG drawing process (S102) for drawing a pattern layout without a background pattern (NOBKG), a proximity effect correction parameter calculating process (S104), a background A BKG drawing step (S106) for drawing a pattern layout having a pattern (BKG), a fogging effect distribution function / fogging effect correction coefficient calculating step (S108), a fogging correction remaining amount calculating step (S110), and a background pattern present ( A BKG drawing step (S112) for drawing a pattern layout of (BKG) and a loading effect distribution function / loading effect correction coefficient calculation step (S114) are performed. The drawing method performed in the drawing apparatus 100 according to the first embodiment includes a drawing data input step (S202), a pattern area ratio map calculation step (S204), and a loading effect / fogging effect correction remaining dimension variation map calculation step. (S206), a reference dose Dbase map / proximity effect correction coefficient η map calculation step (S208), a fogging effect correction irradiation coefficient Df calculation step (S210), a fogging effect dose amount calculating step (S212), and a fogging effect A series of steps such as a remaining correction amount CDres map / fogging effect correction coefficient θ map calculation step (S214), a determination step (S216), an irradiation amount calculation step (S218), and a drawing step (S220) are performed.

  As a NOBKG drawing step (S102), a pattern layout without a background pattern (NOBKG) is drawn.

  FIG. 4 is a diagram showing an example of a pattern layout without a background pattern (NOBKG) in the first embodiment. An evaluation pattern is drawn by changing the proximity effect correction coefficient η for each of a plurality of reference doses Dbase. The evaluation pattern (second evaluation pattern) with no background pattern (NOBKG) is, for example, in each case of proximity effect density U (x) = 0 (0%), 0.5 (50%), 1 (100%) Prepare a pattern layout. Here, the proximity effect density U (x) is defined as a value obtained by convolving and integrating the distribution function g (x) with the pattern area density ρ (x) in the proximity effect mesh in a range equal to or greater than the influence range of the proximity effect. The proximity effect mesh preferably has a size of, for example, about 1/10 of the influence range of the proximity effect, and for example, a size of about 1 μm is preferable. The proximity effect density U (x) can be defined by the following equation (1). x is a vector indicating the position.

  Since the proximity effect density U (x) = 0 actually means that there is no pattern, it is approximated by drawing, for example, one line pattern for measurement in a state where there is nothing else in the influence range of the proximity effect. Can be obtained. On the other hand, the proximity effect density U (x) = 1 is a pattern in the entire mesh including the periphery, and the dimension cannot be measured. Therefore, the measurement line pattern is set to 1 for example in a state where the periphery is completely filled with the pattern. Can be approximated by drawing one. Also, for example, assuming a density of 50%, when a 1: 1 line and space pattern is drawn, the mesh size is small, so only one line pattern is used for one mesh, and only a space pattern is used for the adjacent mesh. Things can happen. In such a case, the pattern area density ρ (x) directly becomes the density in the mesh regardless of the surroundings. On the other hand, by using the proximity effect density U (x), each mesh can be calculated as 50% density. Here, the proximity effect density U (x) to be set is not limited to 0%, 50%, and 100%. For example, it is also preferable to use any one of 10% or less, 50%, and 90% or more. Moreover, you may measure by not only three types but another number. For example, four or more types may be measured.

Here, since the pattern layout has no background pattern (NOBKG), the layout is such that no other peripheral patterns are arranged in the range of influence of the fogging effect around the evaluation pattern.

  As the proximity effect correction parameter calculation step (S104), the proximity effect correction parameter is calculated from the result of drawing the pattern layout without the background pattern (NOBKG) described above.

  FIG. 5 is a graph showing an example of correlation data between the pattern dimension CD and the dose D in the first embodiment. The vertical axis represents the pattern dimension CD, and the horizontal axis represents the dose D in logarithm. Here, for example, the results obtained by experiments for each case of the proximity effect density U (x) = 0 (0%), 0.5 (50%), and 1 (100%) are shown.

  FIG. 6 is a graph showing an example of correlation data between the pattern dimension CD and the proximity effect correction coefficient η in the first embodiment. The vertical axis represents the pattern dimension CD, and the horizontal axis represents the proximity effect correction coefficient η. Here, correlation data of the pattern dimension CD depending on the proximity effect correction coefficient η for each proximity effect density U (x) is shown. By performing proximity effect correction with η at the intersection of the graphs of each proximity effect density U (x), it can be corrected to a constant size CD regardless of the proximity effect density U (x).

  FIG. 7 is a graph showing an example of correlation data of the pattern dimension CD, the proximity effect correction coefficient η, and the reference dose Dbase in the first embodiment. In FIG. 7, the difference from the pattern dimension obtained under the irradiation condition which is the isofocal condition is shown as ΔCD. Here, correlation data between the proximity effect correction coefficient η that can be corrected to a constant size CD regardless of the proximity effect density U (x) and the reference dose Dbase is shown. As described above, there is a proximity effect correction coefficient η that matches well with the proximity effect correction for each reference dose Dbase. As described above, the correlation between the pattern dimension error ΔCD and the reference dose Dbase is calculated, and the correlation information is created. Similarly, the correlation between the pattern dimension error ΔCD and the proximity effect correction coefficient η is calculated, and correlation information is created.

  As a BKG drawing step (S106), a pattern layout having a background pattern (BKG) is drawn. Here, drawing is performed while correcting the proximity effect using a pattern size obtained under the irradiation condition that is an isofocal condition, that is, a set of the reference dose Dbase and the proximity effect correction coefficient η at ΔCD = 0.

  FIG. 8 is a diagram illustrating an example of a pattern layout with a background pattern (BKG) according to the first embodiment. The background pattern presence (BKG) evaluation pattern (first evaluation pattern) is, for example, each case of proximity effect density U (x) = 0 (0%), 0.5 (50%), 1 (100%) Prepare a pattern layout. For example, a plurality of evaluation patterns are arranged in a line so as to be arranged in the x direction at the center of the pattern layout with a background pattern (BKG), and the entire y-direction and -y direction of the plurality of evaluation pattern rows arranged in a line are arranged. Place a pattern on In other words, the evaluation pattern is arranged so as to cross the background pattern. Thus, a pattern layout having an area density of substantially 100% is formed within the fogging influence range. Of the plurality of evaluation pattern rows arranged in a line, the central plurality of evaluation patterns are drawn while performing the fogging effect correction with the fogging effect correction coefficient θ being variable in addition to the proximity effect correction. On the other hand, a plurality of evaluation pattern rows arranged in a line are drawn without performing fogging effect correction. When drawing a pattern layout with a background pattern (BKG), a pattern layout without a background pattern (NOBKG) is also drawn at the same time as shown in FIG. The evaluation pattern (second evaluation pattern) of the pattern layout having no background pattern (NOBKG) is similar to the evaluation pattern (first evaluation pattern) having the background pattern (BKG), for example, proximity effect density U (x) = A pattern layout is prepared for each of 0 (0%), 0.5 (50%), and 1 (100%). The evaluation pattern with no background pattern (NOBKG) is drawn while performing the fogging effect correction with the fogging effect correction coefficient θ being variable in addition to the proximity effect correction.

  As the fogging effect distribution function / fogging effect correction coefficient calculation step (S108), the fogging effect distribution function and the fogging effect correction coefficient θ are calculated.

  FIG. 9 is a diagram showing an example of the relationship between the pattern dimension and the fogging effect correction coefficient in the first embodiment. In FIG. 9, the vertical axis indicates the pattern dimension CD, and the horizontal axis indicates the fogging effect correction coefficient θ. In the example of FIG. 9, the pattern dimension CD is shown when drawing is performed while the fogging effect correction coefficient θ is variable and the fogging effect correction is performed. As in FIG. 2, in the pattern layout with the background pattern (BKG), the CD and θ values at the position A whose dimensions do not change due to the proximity effect density are obtained. The pattern dimension CD does not coincide with the pattern dimension CD whose dimension does not change due to the proximity effect density in the pattern layout without a background pattern (NOBKG). In the first embodiment, the fogging effect correction coefficient θ0 at the position A where the dimension does not change depending on the proximity effect density in the pattern layout with the background pattern (BKG) is obtained.

  FIG. 10 is a diagram showing an example of the correlation between the fogging effect correction coefficient θ0 and the fogging effect dose amount Df in the first embodiment. In FIG. 10, the vertical axis represents the fogging effect correction coefficient θ, and the horizontal axis represents the fogging effect dose amount Dfog. Since the fogging effect correction coefficient θ0 varies depending on the fogging effect dose amount Dfog, the fogging effect dose amount Dfog is made variable, and the fogging effect at the position A where the size does not change depending on the proximity effect density in the pattern layout with the background pattern (BKG). A correction coefficient θ0 is obtained. In this way, the correlation between θ and Dfog is calculated.

  FIG. 11 is a diagram illustrating an example of the fogging effect distribution function in the first embodiment. In FIG. 11, the vertical axis indicates the pattern dimension CD, and the horizontal axis indicates the position x. A distribution function of the fogging effect can be obtained by drawing the evaluation pattern so as to cross the background pattern without correcting the fogging effect. Thereby, the radius σF of the fogging effect distribution function is obtained.

  As the fog correction remaining amount calculating step (S110), the fog effect remaining correction amount CDres is calculated. As a result of rendering while performing the fogging effect correction with the fogging effect correction coefficient θ being variable, the pattern dimension CD at the position A where the dimension does not change due to the proximity effect density in the pattern layout with the background pattern (BKG) shown in FIG. The difference from the pattern dimension CD without the background pattern (NOBKG) is the remaining fogging effect correction amount CDres.

  FIG. 12 is a diagram showing an example of the correlation between the fogging effect correction remaining amount CDres and the fogging effect dose amount Df in the first embodiment. In FIG. 12, the vertical axis represents the fogging effect correction remaining amount CDres, and the horizontal axis represents the fogging effect dose amount Dfog. Since the fogging effect correction remaining amount CDres differs depending on the fogging effect dose amount Dfog, the fogging effect dose amount Dfog is made variable, and the fogging at the position A where the size does not change due to the proximity effect density in the pattern layout with the background pattern (BKG). The effect correction remaining amount CDres is obtained. In this way, the correlation between CDres and Dfog is calculated.

  As a BKG drawing step (S112), a pattern layout with a background pattern (BKG) is drawn. Here, the proximity effect is corrected using the pattern size obtained under the irradiation condition as the isofocal condition, that is, the reference dose Dbase at ΔCD = 0 and the proximity effect correction coefficient η, and the fogging is performed using θ0. Draw while correcting the effect. The pattern layout with a background pattern (BKG) is the same as in FIG. Among the plurality of evaluation pattern rows arranged in a line, the central evaluation pattern is subjected to the loading effect correction by changing the loading effect correction coefficient γ in addition to the proximity effect correction and the fogging effect correction. Draw while. On the other hand, a plurality of evaluation pattern rows arranged in a line are drawn without performing loading effect correction. When drawing a pattern layout with a background pattern (BKG), a pattern layout without a background pattern (NOBKG) is also drawn at the same time as shown in FIG. The evaluation pattern (second evaluation pattern) of the pattern layout having no background pattern (NOBKG) is similar to the evaluation pattern (first evaluation pattern) having the background pattern (BKG), for example, proximity effect density U (x) = A pattern layout is prepared for each of 0 (0%), 0.5 (50%), and 1 (100%). The evaluation pattern without the background pattern (NOBKG) is drawn while performing the loading effect correction by changing the loading effect correction coefficient γ in addition to the proximity effect correction and the fogging effect correction.

  As a loading effect distribution function / loading effect correction coefficient calculation step (S114), a loading effect distribution function and a loading effect correction coefficient γ are calculated.

  FIG. 13 is a diagram showing an example of the relationship between the pattern dimension and the loading effect correction coefficient in the first embodiment. In FIG. 13, the vertical axis indicates the pattern dimension CD, and the horizontal axis indicates the loading effect correction coefficient γ. In the example of FIG. 13, the pattern dimension CD is shown when drawing is performed while the loading effect correction coefficient γ is variable and the loading effect is corrected. In general, since the loading effect dose amount does not depend on the proximity effect density, the graphs of the proximity effect densities overlap in the pattern layout with the background pattern (BKG). In the first embodiment, the loading effect correction coefficient is set so that the difference between the pattern dimension in the pattern layout with the background pattern (BKG) and the pattern dimension in the pattern layout without the background pattern (NOBKG) becomes the remaining fogging effect correction amount CDres. Find γ0. In other words, the first evaluation pattern when the proximity effect, the fogging effect, and the loading effect are corrected with respect to the first evaluation pattern with the background pattern (BKG) in which another pattern is arranged within the range of influence of the fogging effect. When the proximity effect, the fogging effect, and the loading effect are corrected with respect to the second evaluation pattern without the background pattern (NOBKG) in which another pattern is not arranged within the range of influence of the fogging effect and the first pattern size The first difference between the second evaluation pattern and the second pattern dimension is the third pattern dimension of the first evaluation pattern when the proximity effect and the fogging effect are corrected with respect to the first evaluation pattern; The remaining fogging effect correction amount CD that becomes the second difference between the fourth pattern dimension of the second evaluation pattern when the proximity effect and the fogging effect are corrected for the second evaluation pattern es and is, loading effect correction coefficient γ0 is set to match.

  FIG. 14 is a diagram illustrating an example of the loading effect distribution function in the first embodiment. In FIG. 14, the vertical axis represents the pattern dimension CD, and the horizontal axis represents the position x. A distribution function of the loading effect can be obtained by drawing the evaluation pattern so as to cross the background pattern without correcting the loading effect. Thereby, the radius σL of the loading effect distribution function is obtained.

  As described above, Dfog-CDres correlation information indicating the correlation between the fogging effect dose amount Dfog and the fogging effect correction remaining amount CDres, which is a fogging effect correction parameter, before the input to the drawing apparatus 100, and the fogging effect. The Dfog-θ correlation information indicating the correlation between the effect dose amount Dfog and the fogging effect correction coefficient θ, and the radius σF of the fogging effect distribution function are obtained. Similarly, ΔCD-Dbase correlation information indicating the correlation between the pattern dimension error ΔCD and the reference dose Dbase, which is a proximity effect correction parameter, and ΔCD indicating the correlation between the pattern dimension error ΔCD and the proximity effect correction coefficient η. -Η correlation information is obtained. Similarly, a loading effect correction coefficient γ, a loading effect distribution function radius σL, and a loading effect size variation amount CDpos (x) depending on the drawing position, which are loading effect correction parameters, are obtained. These pieces of information are input to the drawing apparatus 100 and stored in the storage device 140.

  In the drawing apparatus 100, preprocessing is performed in the control computer 110 to create various maps, and the control computer 120 uses the obtained maps to perform drawing operations and dose calculation in real time.

  In the drawing data input step (S202), the pattern area ratio map creation unit 10 inputs drawing data from the storage device 142.

  As the pattern area ratio map calculating step (S204), the pattern area ratio map creating unit 10 calculates a pattern area ratio ρ (x) arranged for each mesh area of a predetermined size. Then, a pattern area ratio map of the entire drawing area is created. For example, the size of the mesh area may be created to be 1/10 of the influence range of the proximity effect. The proximity effect mesh size is preferably about 1 μm, for example. Furthermore, it is preferable that the size is 1/10 of the influence range of the fogging effect and the loading effect. The fogging effect and loading effect mesh size is preferably about 1 mm, for example.

  In the loading effect / fogging effect correction remaining dimension fluctuation amount map calculation step (S206), the loading quantity map creation unit 12 reads the loading effect correction coefficient γ, the radius σL of the distribution function, and the position-dependent loading effect dimension fluctuation amount from the storage device 140. Read CDpos (x). Then, a value obtained by convolving and integrating the distribution function g (x, σL) with the product of the loading effect correction coefficient γ, the fogging effect, and the pattern area density ρ (x) in the loading effect mesh within the range of the influence of the loading effect (area) A value (size fluctuation amount CDerr (x)) obtained by adding the position-dependent loading effect size fluctuation amount CDpos (x) and the fogging effect correction remaining CDres (x) to the rate-dependent size fluctuation amount) is calculated. The dimensional variation amount CDerr (x) can be defined by the following equation (2). x is a vector indicating the position. First, θ (x) when CDres (x) = 0 and Dfog (x) = 0 is input as an initial value. Then, a dimensional variation amount CDerr (x) map of the entire drawing area is created. The loading amount map creation unit 12 is an example of a dimensional variation calculation unit.

  As the reference dose Dbase map / proximity effect correction coefficient η map calculation step (S208), the reference dose map calculation unit 16 calculates a reference dose Dbase that corrects the dimensional variation amount together with the dimensional variation amount due to the proximity effect. Specifically, ΔCD-Dbase correlation information is read from the storage device 140, and Dbase for correcting the obtained dimension variation amount CDerr (x) while maintaining proximity effect correction is calculated. The reference dose map calculation unit 16 is an example of a reference dose calculation unit.

  Then, the proximity effect correction coefficient map calculation unit 17 calculates a proximity effect correction coefficient for correcting the dimensional variation amount together with the dimensional variation amount due to the proximity effect. Specifically, ΔCD-η correlation information is read from the storage device 140, and η for correcting the obtained dimensional variation CDerr (x) while maintaining proximity effect correction is calculated. The proximity effect correction coefficient map calculation unit 17 is an example of a proximity effect correction coefficient calculation unit.

  As described above, a set of Dbase and η is calculated. Since the reference dose Dbase depends on the dimensional error ΔCD, it can be obtained as Dbase (x) = f1 (CDerr (x)). Similarly, since the proximity effect correction coefficient η depends on the dimensional error ΔCD, it can be obtained as η (x) = f2 (CDerr (x)). Then, a reference dose Dbase map and a proximity effect correction coefficient η map for the entire drawing area are created.

  In addition, since the area ratio ρ (x) map and the proximity effect correction coefficient η map of the entire drawing area have been created, it is preferable to calculate the proximity effect correction irradiation coefficient Dp depending on these. Therefore, the proximity effect correction irradiation coefficient map calculation unit 18 calculates the proximity effect correction irradiation coefficient Dp (x) with reference to the area ratio ρ (x) map of the entire drawing region and the proximity effect correction coefficient η map. Since the proximity effect correction irradiation coefficient Dp (x) depends on the area ratio ρ (x) and the proximity effect correction coefficient η, it can be calculated by Dp (x) = f3 (ρ (x), η (x)). Then, a proximity effect correction irradiation coefficient Dp map for the entire drawing area is created. Here, it is desirable that the mesh size is a proximity effect mesh, but the mesh size is not limited to this, and any fine mesh may be used as long as it is not limited by the calculation speed.

  As the fogging effect correction irradiation coefficient Df calculation step (S210), the fogging effect correction irradiation coefficient map calculation unit 20 uses the fogging effect correction coefficient θ, the reference irradiation amount Dbase (x), and the proximity effect correction coefficient η (x). A fogging effect correction irradiation coefficient Df for correcting the fogging effect is calculated. The fogging effect correction irradiation coefficient map calculation unit 20 is an example of a fogging effect correction irradiation coefficient calculation unit. The fogging effect correction irradiation coefficient Df can be obtained as a value depending on the reference irradiation amount Dbase, the proximity effect correction coefficient η, and the fogging effect correction coefficient θ. Therefore, Df (x) = f4 (Dbase (x), η (x), θ (x)) can be calculated. Then, a fogging effect correction irradiation coefficient Df map for the entire drawing area is created.

  As the fogging effect dose amount calculating step (S212), the fogging effect dose amount calculation unit 22 calculates a fogging effect dose amount Dfog. The fogging effect dose Dfog is obtained by applying a distribution function g (x, σF) to the product of the reference irradiation dose Dbase (x), the proximity effect correction irradiation coefficient Dp (x), the fogging effect correction irradiation coefficient Df, and the fogging effect correction coefficient θ. It can be obtained by performing convolution integral within the range of influence of the effect. Such fogging effect dose Dfog can be defined by the following equation (3). x is a vector indicating the position.

  As the remaining fogging effect correction amount CDres map / fogging effect correction coefficient θ map calculation step (S214), the fogging effect correction coefficient map calculation unit 26 performs the fogging effect correction in which the pattern dimensions after the fogging effect correction match regardless of the proximity effect density. Obtain the coefficient θ. Specifically, since the fogging effect correction coefficient θ depends on the fogging effect dose amount Dfog, the fogging effect correction coefficient map calculation unit 26 reads the Dfog-θ correlation information from the storage device 140 and calculates the calculated fogging effect dose amount Dfog. The fogging effect correction coefficient θ corresponding to is obtained. The fogging effect correction coefficient θ can be obtained as a value depending on the fogging effect dose amount Dfog. Therefore, it is computable by (theta) (x) = f5 (Dfog (x)). The fogging effect correction coefficient map calculation unit 26 is an example of a fogging effect correction coefficient acquisition unit. Then, a fogging effect correction coefficient θ map for the entire drawing area is created.

  Similarly, the remaining fogging effect correction amount map calculation unit 24 acquires the remaining fogging effect correction amount CDres when the fogging effect is corrected using the fogging effect correction coefficient θ. Specifically, since the remaining fogging effect correction amount CDres depends on the fogging effect dose amount Dfog, the fogging effect correction coefficient map calculation unit 26 reads out the Dfog-CDres correlation information from the storage device 140 and calculates the calculated fogging effect dose amount. The remaining fog effect correction amount CDres corresponding to Dfog is acquired. The remaining fog effect correction amount CDres can be obtained as a value depending on the fog effect dose amount Dfog. Therefore, it can be calculated by CDres (x) = f6 (Dfog (x)). The fogging effect correction remaining amount map calculation unit 24 is an example of a fogging effect correction remaining amount acquisition unit. Then, a fog effect correction remaining amount CDres map of the entire drawing area is created.

  In the determination step (S216), the determination unit 28 determines that the absolute value of the difference between the fog effect correction remaining amount CDres (x) n−1 obtained last time and the fog effect correction remaining amount CDres (x) n obtained this time is within the threshold value. Determine whether or not. If the result of determination is greater than the threshold, processing returns to S206. Then, the loading effect / fogging effect correction remaining until the absolute value of the difference between the fog effect correction remaining amount CDres (x) n−1 obtained last time and the fog effect correction remaining amount CDres (x) n obtained this time is within the threshold value. The dimension variation map calculation step (S206) to the determination step (S216) are repeated.

  In the second and subsequent loading effect / fogging effect correction remaining size variation map calculation step (S206), the fogging effect correction remaining amount CDres (x) obtained in the previous routine is subjected to dimensional variation by the fogging effect correction remaining amount adding unit 14. It is added to the quantity CDerr (x) map. As described above, the fogging effect correction remaining amount adding unit 14 calculates an addition value of the dimensional variation amount due to the loading effect depending on the loading effect correction coefficient and the fogging effect correction remaining amount CDres (x). The added dimension variation amount becomes a new dimension variation amount CDerr (x). The fogging effect correction remaining amount adding unit 14 is an example of a dimension variation calculating unit. Here, although the fogging effect correction remaining amount adding unit 14 adds, the loading amount map creating unit 12 uses the fogging effect correction remaining amount CDres (x) obtained in the previous routine to obtain the equation (2). The content may be recalculated.

  In the second and subsequent reference dose Dbase map / proximity effect correction coefficient η map calculation step (S208), the reference dose map calculation unit 16 performs the dimension variation amount CDerr (including the fogging effect correction remaining amount CDres (x)). A reference dose Dbase for correcting x) together with the dimensional variation due to the proximity effect is calculated. The proximity effect correction coefficient map calculation unit 17 calculates a proximity effect correction coefficient that corrects the dimensional variation amount CDerr (x) including the fogging effect correction remaining amount CDres (x) together with the dimensional variation amount due to the proximity effect. Specifically, a set of Dbase and η for correcting the newly obtained dimension variation amount CDerr (x) while maintaining the proximity effect correction is calculated. Then, the proximity effect correction irradiation coefficient Dp (x) is also calculated using η obtained this time.

  In the second and subsequent fogging effect correction irradiation coefficient Df calculation step (S210), the fogging effect correction irradiation coefficient Df is calculated using the combination of θ obtained in the previous routine and Dbase and η obtained in the current routine. Calculated.

  In the second and subsequent fogging effect dose calculation step (S212), the fogging effect dose amount Dfog is calculated using θ obtained in the previous routine, Dbase, Dp (x), and Df obtained in the current routine. Calculated.

  In the second and subsequent fogging effect correction remaining amount CDres map / fogging effect correction coefficient θ map calculation step (S214), the fogging effect correction remaining amount CDres and the fogging effect corresponding to the fogging effect dose amount Dfog obtained in the current routine are obtained. A correction coefficient θ is calculated.

  As described above, the fogging effect correction coefficient θ and the fogging effect correction remaining amount CDres are fed back until the difference between the fogging effect correction remaining amount CDres obtained last time and the fogging effect correction remaining amount CDres obtained this time is within the threshold value. The size variation amount CDerr (x), the reference irradiation amount Dbase, the proximity effect correction coefficient η, the fogging effect correction irradiation coefficient Df, the fogging effect dose amount Dfog, the fogging effect correction coefficient θ, and the remaining fogging effect correction remaining amount CDres are repeatedly obtained. It is done. Although there is no limit to the number of repetitions, it is usually possible to perform correction with considerably high accuracy by repeating once (performing a routine twice). Then, the area ratio ρ (x) map and the finally obtained Dbase map, η map, and Df map are output to the control computer 120 by the output unit 30.

  As the dose calculation step (S218), the proximity effect correction coefficient map calculation unit 32 refers to the input area ratio ρ (x) map and the proximity effect correction coefficient η map, and the proximity effect correction irradiation coefficient Dp (x). Is calculated. Since the proximity effect correction irradiation coefficient Dp (x) depends on the area ratio ρ (x) and the proximity effect correction coefficient η, it can be calculated by Dp (x) = f3 (ρ (x), η (x)) described above. . Then, a proximity effect correction irradiation coefficient Dp map for each drawing calculation processing unit is created. The irradiation amount calculation unit 34 calculates the irradiation amount D of the electron beam at the time of drawing using the input Dbase map and Df map and the calculated proximity effect correction irradiation coefficient Dp map. The dose D can be defined by the product of Dbase, Dp, and Df, and can be obtained by D (x) = Dbase (x) · Dp (ρ (x), η (x)) · Df (x). Then, a dose D map for each drawing calculation processing unit is created.

  Then, the irradiation time calculation unit 36 calculates the irradiation time T of the electron beam 200 at each position in the drawing area. Since the dose D can be defined by the product of the irradiation time T and the current density J, the irradiation time T can be obtained by dividing the dose D by the current density J. The calculated irradiation time is output to the deflection control circuit 132.

  As the drawing step (S220), the drawing unit 150 draws a desired pattern on the sample 101 using the electron beam 200 having an irradiation amount obtained for each map position. Specifically, it operates as follows. The deflection control circuit 132 outputs a digital signal for controlling the irradiation time for each shot to the DAC amplifier unit 130. The DAC amplifier unit 130 converts the digital signal into an analog signal, amplifies it, and applies it to the blanking deflector 212 as a deflection voltage.

  When the electron beam 200 emitted from the electron gun 201 (emission unit) passes through the blanking deflector 212, it is controlled by the blanking deflector 212 so as to pass through the blanking aperture 214 in the beam ON state. In the beam OFF state, the entire beam is deflected so as to be shielded by the blanking aperture 214. The electron beam 200 that has passed through the blanking aperture 214 until the beam is turned off after the beam is turned off becomes one shot of the electron beam. The blanking deflector 212 controls the direction of the passing electron beam 200 to alternately generate a beam ON state and a beam OFF state. For example, the voltage may be applied to the blanking deflector 212 when the beam is OFF, without applying a voltage when the beam is ON. The irradiation amount per shot of the electron beam 200 irradiated on the sample 101 is adjusted with the irradiation time T of each shot.

  As described above, the electron beam 200 of each shot generated by passing through the blanking deflector 212 and the blanking aperture 214 illuminates the entire first shaping aperture 203 having a rectangular hole, for example, a rectangular hole, by the illumination lens 202. To do. 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 shaping aperture 203 is projected onto the second shaping aperture 206 by the projection lens 204. The deflector 205 controls the deflection of the first aperture image on the second shaping aperture 206 and can change the beam shape and dimensions (variable shaping is performed). Such variable shaping is performed for each shot, and is usually shaped into different beam shapes and dimensions for each shot. The electron beam 200 of the second aperture image that has passed through the second shaping aperture 206 is focused by the objective lens 207, deflected by the deflector 208, and placed on the XY stage 105 that moves continuously. The desired position is irradiated. As described above, a plurality of shots of the electron beam 200 are sequentially deflected onto the sample 101 serving as the substrate by each deflector.

  As described above, according to the first embodiment, the remaining fogging effect correction that is a dimensional variation that could not be assumed in the fogging effect model can be corrected without breaking the proximity effect correction. Therefore, it is possible to draw with highly accurate dimensions.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

  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 apparatuses and methods 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.

DESCRIPTION OF SYMBOLS 10 Pattern area ratio map preparation part 12 Loading amount map preparation part 14 Coverage effect correction remaining amount addition part 16 Reference irradiation amount map calculation part 17 Proximity effect correction coefficient map calculation part 18 Proximity effect correction irradiation coefficient map calculation part 20 Coverage effect correction irradiation Coefficient map calculation unit 22 Fog effect dose amount calculation unit 24 Fog effect correction remaining amount calculation unit 26 Fog effect correction coefficient map calculation unit 28 Determination unit 30 Output unit 32 Proximity effect correction coefficient map calculation unit 34 Irradiation amount calculation unit 36 Irradiation time calculation Unit 38 drawing processing control unit 100 drawing device 101 sample 102 electron column 103 drawing room 105 XY stage 110, 120 control computer 111, 121 memory 130 DAC amplifier unit 132 deflection control circuit 140, 142 storage device 150 drawing unit 160 control unit 200 Electron beam 201 electron 202 Illumination lens 203 First shaping aperture 204 Projection lens 205 Deflector 206 Second shaping aperture 207 Objective lens 208 Deflector 212 Blanking deflector 214 Blanking aperture 330 Electron beam 340 Sample 410 First aperture 411 Opening 420 Second Two apertures 421 Variable shaped aperture 430 Charged particle source

Claims (5)

A fogging effect correction coefficient acquisition unit that acquires a fogging effect correction coefficient in which the pattern dimensions after the fogging effect correction match regardless of the proximity effect density;
A fogging effect correction remaining amount acquisition unit that acquires a correction remaining amount of the fogging effect when correcting the fogging effect using the fogging effect correction coefficient;
A reference dose calculation unit for calculating a reference dose for correcting the remaining fog correction correction amount together with a dimensional variation due to the proximity effect;
A proximity effect correction coefficient calculation unit that calculates a proximity effect correction coefficient for correcting the fogging effect correction remaining amount together with a dimensional variation amount due to the proximity effect;
A fogging effect correction irradiation coefficient calculation unit for calculating a fogging effect correction irradiation coefficient for correcting a fogging effect using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient;
A dose calculation unit that calculates a dose of the charged particle beam when drawing using the fogging effect correction irradiation coefficient;
A drawing unit for drawing a pattern on the sample with the irradiation amount;
A charged particle beam drawing apparatus comprising:   The fogging effect correction coefficient and the remaining fogging effect correction remaining amount are fed back until the difference between the previously obtained fogging effect correction remaining amount and the currently obtained fogging effect correction remaining amount falls within the threshold value again. 2. The charged particle beam drawing apparatus according to claim 1, wherein the fogging effect correction remaining amount, the reference irradiation amount, the proximity effect correction coefficient, and the fogging effect correction irradiation coefficient are repeatedly obtained. Further comprising a fogging effect dose amount calculation unit for calculating a fogging effect dose amount caused by a fogging effect using the reference irradiation amount and the proximity effect correction coefficient,
3. The charged particle beam drawing apparatus according to claim 1, wherein the fogging effect correction coefficient and the remaining fogging effect correction amount are acquired depending on a fogging effect dose amount. The first pattern size of the first evaluation pattern when the proximity effect, the fogging effect, and the loading effect are corrected with respect to the first evaluation pattern in which another pattern is arranged within the range of influence of the fogging effect, and the fogging The first pattern dimensions of the second evaluation pattern when the proximity effect, the fogging effect, and the loading effect are corrected with respect to the second evaluation pattern in which another pattern is not arranged within the effect influence range. The difference is the third pattern size of the first evaluation pattern when the proximity effect and the fogging effect are corrected for the first evaluation pattern, and the proximity effect and the fogging effect for the second evaluation pattern. A storage unit for storing a loading effect correction coefficient set so as to match a second difference between the second evaluation pattern and the fourth pattern dimension when the second evaluation pattern is corrected,
A dimensional variation calculation unit that calculates an added value of the dimensional variation due to the loading effect depending on the loading effect correction coefficient and the fogging effect correction remaining amount;
Further comprising
The reference dose calculation unit calculates the reference dose so as to correct the added dimensional variation amount together with the dimensional variation amount due to the proximity effect,
The proximity effect correction coefficient calculation unit calculates the proximity effect correction coefficient so as to correct the added dimensional variation amount together with the dimensional variation amount due to the proximity effect,
The fogging effect dose amount calculating unit calculates the fogging effect dose amount using the reference irradiation amount based on the added dimensional variation amount and the proximity effect correction coefficient,
The fogging effect correction coefficient acquisition unit acquires the fogging effect correction coefficient according to the fogging effect dose based on the added dimensional variation amount,
The fogging effect correction remaining amount acquisition unit acquires the fogging effect correction remaining amount according to the fogging effect dose based on the added dimensional variation amount;
The fogging effect correction irradiation coefficient calculation unit calculates the fogging effect correction irradiation coefficient using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient based on the dimensional variation added together. The charged particle beam drawing apparatus according to claim 3. A step of obtaining a fogging effect correction coefficient in which the pattern dimensions after the fogging effect correction match regardless of the proximity effect density;
Obtaining the remaining correction amount of the fogging effect when the fogging effect is corrected using the fogging effect correction coefficient;
Calculating a reference irradiation amount for correcting the fogging effect correction remaining amount together with a dimensional variation amount due to a proximity effect;
Calculating a proximity effect correction coefficient for correcting the remaining fogging effect correction amount together with a dimensional variation amount due to the proximity effect;
Calculating a fogging effect correction irradiation coefficient for correcting a fogging effect using the fogging effect correction coefficient, the reference irradiation amount, and the proximity effect correction coefficient;
Calculating the irradiation amount of the charged particle beam when drawing using the fogging effect correction irradiation coefficient;
Drawing a pattern on the sample with the irradiation amount;
A charged particle beam drawing method comprising: