JP3393412B2 - Exposure method and exposure apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure method and exposure apparatus. The present invention can be used in various technical fields in which a desired pattern is formed by performing pattern-wise exposure. For example, it is used by applying to a mask pattern formation when manufacturing a photomask used for pattern exposure at the time of manufacturing an electronic material (semiconductor device etc.), or an electron beam drawing technique for directly exposing a semiconductor wafer. be able to.

[0002]

2. Description of the Related Art A variety of energy rays such as an electron beam and visible / ultraviolet light are used to irradiate an object to be exposed with light. The limit of resolution of pattern exposure is determined by various factors, but a phenomenon called proximity effect may be a major factor that governs the resolution limit. What is the proximity effect?
It is said that a certain pattern is affected by scattering of irradiation energy from a pattern adjacent to the certain pattern.

Since this proximity effect is prominent in electron beam writing (EB lithography), the prior art will be described below by taking this case as an example.

Generally, in EB lithography,
It is known that the proximity effect dominates the limit of resolution, which is a serious problem in photomask fabrication for fine processing and wafer direct writing.

The cause of the proximity effect phenomenon is that electrons are scattered in the solid. FIG. 8 shows an electron scattering model in the photomask structure.
The scattering state is shown when a plurality of electrons are implanted at one point on the surface of. First, some of the injected electrons collide with atoms in the resist 1 and are scattered in the incident direction,
Next, among the electrons that have reached the chromium film 2, there are also electrons that collide with the chromium atoms, scatter in the direction opposite to the incident direction, and expose the resist again.

The first scattering that spreads in the same direction as the incident direction is called forward scattering, and the second scattering that spreads in a direction opposite to the incident direction is called backscattering.

The magnitude of these scatterings varies depending on the type of resist, the film thickness of the resist, the material of the substrate, the accelerating voltage of the drawing apparatus, etc., but the spread due to forward scattering (forward scattering radius) is generally small, Although it is on the order of 1 μm or less, it is known that the spread due to backscattering (backscattering radius) is large and reaches several μm to several tens μm.
Photomask pattern size is generally 5 device size.
However, due to the progress of fine processing in recent years, it is already on the order of several microns, which is affected by the proximity effect.

The proximity effect depends on the shape of the pattern.
It can be classified into types. FIG. 9 shows two types of proximity effects.

FIG. 9 (a) compares the design dimension in the case of an isolated minute pattern (there is no pattern in the neighborhood) with the actual finished dimension. In a minute pattern as shown in FIG. 9A, incident electrons are scattered outside the pattern, so that the stored energy in the design dimension cannot reach a desired value, and as a result, the finished dimension is small. It gets smaller. That is, for the design dimension 6a,
As shown in FIG. 10A, the electrons that have just entered the corner have the distribution 7a, and as can be understood from the figure, only 1/4 contributes to the exposure of the design pattern 6a. Further, the electrons incident on the side have the distribution shown in 7b, and become 1/2 as well. Therefore, 6b in FIG.
The pattern with rounded four corners, as shown in FIG. 3, is formed in a pattern in which the sides are aimed, though not shown. Such a phenomenon is called an internal proximity effect or an in-graphic proximity effect.

On the other hand, FIG. 9B shows the proximity effect phenomenon when the patterns are close to each other. If the patterns are close to each other, design pattern size 6
Although the pattern c and 6d are not directly irradiated with electrons between these patterns, FIG.
As shown by reference numerals 7c and 7d, the accumulated energy reaches a predetermined value due to the scattering of electrons from the patterns on both sides, and the energy is patterned.
The shape may be as shown by 6f.

Such a phenomenon that close patterns are in contact with each other or are distorted is called mutual proximity effect or inter-graphic proximity effect. The above two types of phenomena are collectively referred to as the proximity effect (see FIG. 11 for the influence of the proximity effect).

As a means for correcting the proximity effect, there is a method in which the electron beam irradiation dose given to each pattern is obtained by numerical calculation and correction is performed.

A conventional general dose correction method according to this is configured to correct both the internal proximity effect and the mutual proximity effect. In this conventional method, as shown in FIG. 13, the pattern is divided into rectangular and trapezoidal (including triangular) elementary figures,
The evaluation points P _{1 to} P ₇ are provided at the midpoints of the sides where the patterns are not in contact with each other.

By calculating the accumulated energy at the evaluation points P _{1 to} P ₇ , the optimum irradiation amount given to the pattern is set. The process of the calculation is shown below (for the conventional technique, see, for example, “Proximity Effect Correction System for Direct Electron Beam Direct Writing” by National Institute of Technology, Nitto
cal Report, Vol. 36 No. 4 Au
g. , 1990).

First, the stored energy at point P ₁ is given by the following equation.

[0016]

[Equation 1]

In the equation (1), the integral term (exposure intensity)
If is expressed in the form of a general formula using K _i , _j , it becomes as follows.

[0018]

[Equation 2]

By satisfying the condition that the accumulated energy at the evaluation point is equal to E _th which is the minimum energy required for patterning, the patterning is performed according to the design dimension, and the following formula is obtained. To be

[0020]

[Equation 3] E _pi −E _th = 0 (3)

When this equation (3) is rewritten in the form of a determinant, the following equation is obtained.

[0022]

[Equation 4]

By solving the equation (4), the doses D ₁ , D ₂ , ..., D _m given to each pattern can be obtained.
In general, the equation (4) has a large number of equations with respect to unknowns, so it must be obtained by iterative calculation using the least squares method. Therefore, if the number of patterns is large, the correction time becomes long. In order to reduce the number of patterns to be calculated at one time, it is necessary to devise a method of dividing the area by the area of a certain area and performing correction calculation in each narrow area.

As described above, in the conventional method, in order to calculate the irradiation dose given to one pattern, it is necessary to consider the relation between the size and the distance of the pattern in the vicinity thereof.
The calculation time becomes extremely long. Therefore, a supercomputer is used, or a plurality of CPUs are connected in parallel and dedicated hardware is used, resulting in high system cost.

[0025]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to shorten the time required for the correction for determining the exposure conditions, and to reduce the system cost. The purpose is to provide a device.

[0026]

Each of the inventions of the present application is as follows.
The above object is achieved by the configuration.

According to a first aspect of the present invention, in an exposure method for exposing a pattern in a position isolated from a neighboring pattern by irradiating the pattern with energy, the size of the pattern to be exposed is used as a parameter, and a plurality of sizes are set. The appropriate exposure dose corresponding to each dimension is obtained in advance by obtaining a distribution formula of irradiation energy scattering and solving it. At this time, the distribution formula of the scattering is the accumulated energy E due to scattering at the evaluation point. The following formula to be used E = energy from own pattern + energy from other pattern in the neighborhood is used, and the formula is established by ignoring the influence of scattering on the pattern from other patterns in the neighborhood. Is the equation for calculating the exposure amount, and E = energy from the pattern of itself is solved by inserting the dimension of the pattern to be exposed into the equation.
Thus, so as to obtain in advance a proper exposure amount corresponding to the dimension of the pattern of the object to be exposed, at the time of exposure depending on the size of the pattern, the there is provided an exposure method for performing exposure irradiated by該適positive exposure led for each dimension And according to the following procedure
Ri An exposure method characterized by performing exposure, thereby is to achieve the above object. Of the exposed object
Obtain the appropriate exposure amount according to the size of each pattern in advance.
A correction table is created based on the results obtained. Exposed body power
Read turn data. Refer to the correction table
It The appropriate exposure amount of each pattern of the exposed object is obtained by the above reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount.

According to a second aspect of the present invention, in an exposure apparatus that performs exposure by irradiating energy in a pattern shape, it is provided with means for storing an appropriate exposure amount obtained in advance for each of a plurality of pattern dimension values, and at the time of exposure , An appropriate exposure amount according to the dimensions of the pattern of the exposed body is derived from the storage means,
In addition to configuring to perform exposure irradiation with this exposure amount ,
The appropriate exposure amount previously obtained and stored is experimentally obtained.
There are multiple methods that are
Irradiation that is set in detail for each size pattern
The amount of exposure was performed to obtain the pattern, and the design dimensions were achieved.
An exposure apparatus , characterized in that an appropriate exposure amount is set at a certain place, thereby achieving the above object
It is a thing.

According to a third aspect of the present invention, an appropriate exposure is performed by obtaining a distribution formula of scattering of irradiation energy in an exposure device that performs exposure by irradiating the pattern-like energy with a pattern in a position isolated from a neighboring pattern. In addition to the configuration in which the exposure is performed by obtaining the amount, the distribution formula of the scattering is the following formula E for obtaining the accumulated energy E due to scattering at the evaluation point: E = energy from own pattern + energy from other neighboring patterns Using the formula, the following formula in which the influence of the scattering on the pattern from the other patterns in the neighborhood is ignored is established, and the formula is used as an equation for calculating the exposure amount, and E = energy from the own pattern Put the dimensions of the pattern to be solved and solve it,
Thus leads to proper exposure amount, and configured to perform exposure irradiated by the proper amount of exposure had conductor, and exposure by the following procedure
An exposure apparatus characterized by performing, thereby is to achieve the above object. Each pattern of the exposed object
The appropriate exposure amount according to the size of each
Create a correction table based on the result. Pattern of exposed object
Read the data. Refer to the correction table. The appropriate exposure amount of each pattern of the exposed object is obtained by the above reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount.

According to a fourth aspect of the present invention, in an exposure apparatus that exposes a pattern in a position isolated from a neighboring pattern by irradiating the pattern with energy, it is appropriate for a plurality of values of the dimension of the pattern according to each dimension. with a configuration that includes a storage means for storing this previously obtained by solving this exposure seeking distribution type of the scattering of radiation energy, the distribution type scattered, dispersed at the evaluation point
The following equation E for calculating the accumulated energy E due to the disturbance = Energy from own pattern + Other patterns in the neighborhood
For formula with use of the energy from down, the other adjacent putter
The following formula ignoring the influence of scattering on the pattern from
And the equation is used as the equation for calculating the exposure amount, and E = energy from the pattern of itself is solved by inserting the dimension of the pattern to be exposed into the equation.
With this configuration, an appropriate exposure amount is derived and stored in the storage means, and at the time of exposure, an appropriate exposure amount according to the dimension of the pattern of the exposed object is derived from the storage means, and exposure irradiation is performed by this exposure amount. in an exposure apparatus characterized by the
Therefore, this achieves the above object.

According to a fifth aspect of the present invention, for the pattern dimension value that the storage means does not have, an approximate value is obtained from the data that the storage means has and an appropriate exposure amount for the pattern dimension value is obtained. The exposure apparatus according to claim 2 or 4 , characterized in that it achieves the above object.

The invention of claim 6 uses a plurality of types of dry plates.
Exposure when forming a photomask for semiconductor device manufacturing
An optical method, in which a correction test is performed for each of the plurality of types of dry plates.
Table is prepared and the correction table has a plurality of values of pattern dimensions.
About the appropriate exposure amount obtained in advance for each dimension
And the pattern of the exposed object
Refer to the correction table for the proper exposure amount according to the dimensions
The exposure dose is used to guide the exposure of the photomask.
In addition to the configuration for performing light irradiation, the correction table
The proper exposure amount was determined by experiments and
The method determined by the test is for patterns of multiple sizes.
Pattern by performing exposure with a finely set irradiation amount for each
And the appropriate dose is the dose when the design dimensions are obtained.
It was those with an exposure method comprising, thereby is to achieve the above object.

The invention of claim 7 uses a plurality of types of dry plates.
Exposure when forming a photomask for semiconductor device manufacturing
An optical method, in which a correction test is performed for each of the plurality of types of dry plates.
Table is prepared and the correction table has a plurality of values of pattern dimensions.
About the appropriate exposure amount obtained in advance for each dimension
And the pattern of the exposed object
Refer to the correction table for the proper exposure amount according to the dimensions
The exposure dose is used to guide the exposure of the photomask.
In addition to the configuration for performing light irradiation, the correction table
The appropriate exposure dose is required to calculate the distribution formula of the scattering of irradiation energy.
It was calculated by and as the distribution formula of the scattering
Is the accumulated energy E due to scattering at the evaluation point
Equation E = energy from one's own pattern + other putters in the neighborhood
And other patterns in the neighborhood for the equation.
From the following equation ignoring the effect of scattering on the pattern
And the equation is used as an equation for calculating the exposure amount, and E = energy from the pattern of itself is solved by inserting the dimension of the pattern to be exposed into the equation.
This leads to the proper exposure amount, and the derived proper exposure amount
It is configured to irradiate with multiple exposures and is exposed by the following procedure.
And an exposure method which achieves the above object. Each pattern of the exposed object
The appropriate exposure amount according to the size of each
Create a correction table based on the result. Pattern of exposed object
Read the data. Refer to the correction table. The appropriate exposure amount of each pattern of the exposed object is obtained by the above reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount.

Each of the inventions described above has the above structure.
It achieves the purpose.

According to each invention, the proper exposure amount for a plurality of values of the pattern dimension is obtained in advance from the experimental value or the calculated value, and the proper exposure amount corresponding to the actual pattern dimension at the time of exposure is derived based on this data. Since the exposure is performed by, the time required for correction can be significantly shortened, the system can be simplified, and it is advantageous in terms of cost.

According to each invention, since the correction calculation is performed by ignoring the influence of the scattering of the neighboring pattern and the exposure is performed by this, the time required for the correction can be remarkably shortened, and the system can be simplified. It is also advantageous in terms of cost.

According to the fifth aspect of the present invention, since the pattern dimension not found in the auxiliary stored data is exposed by the approximate value based on the stored data, proper exposure can be easily performed for any pattern dimension. You can

In each of the inventions, the influence of scattering of neighboring patterns can be calculated in advance, or a correction table can be prepared in advance from experimental data and incorporated in the calculation means.

By doing so, the optimum irradiation amount can be instantaneously obtained by referring to the correction table immediately after reading the pattern dimension from the data file.

FIG. 1 shows an example of the flow of the data processing system of this high-speed correction method.

According to such a flow, first, a correction table is created, then pattern data is read one by one, and the correction table is referred to, so that correction can be easily performed, and thereby proper exposure can be realized.

The correction table is, for example, Table 1 described later.
, Corresponding to the length of the side of the square
It can be configured to set the irradiation amount at points of 1.05 μm intervals and 0.05 μm. In the case of a rectangular pattern using this, there are a method of drawing a table by the average value of the short side and the long side, and a method of calculating the square root by calculating the pattern area. When speed is pursued, it is better to draw a table with the average value, but when accuracy is strict, it is better to use the square root.

Next, a method of performing correction by ignoring the influence of scattering of the proximity pattern according to the inventions of claims 3, 4, 7, and 8 of the present application will be described.

The present invention can be strictly applied only to a pattern in which the influence of other patterns can be ignored, and can be used as a simple means when the influence is not so important. Further, even when there is an influence of another pattern, it can be used as a first approximation value or as a method for determining a rough amount.

In particular, it can be suitably used when the proximity effect correction is limited to a pattern in which the internal proximity effect occurs among the two types of proximity effect phenomena. The pattern in which the internal proximity effect phenomenon occurs is typically the pattern existing in the contact hole layer.

In the manufacture of photomasks, the internal proximity effect that the pattern of the contact hole layer becomes small poses a problem. FIG. 11 illustrates this. This shows the relationship between the design dimension and the error in the photomask (5 times reticle). That is, FIG. 11 shows an acceleration voltage of 20 kV, an electron beam positive resist EBR-9 (film thickness 0.
5 is a graph simulating the error between the design dimension and the finished dimension of the contact hole pattern and the line pattern at 5 μm).

According to this figure, an error occurs in the contact hole pattern from 5 μm or less (corresponding to the 1.0 μm rule in an actual device), and the error rapidly increases as the design size decreases. On the other hand, the line pattern is 1.75 μm (actual device 0.35 μm).
(corresponding to the μm rule), the error is 0.1 μm or less,
The point at which an error occurs is delayed compared to the contact hole pattern.

Considering the manufacture of photomasks, the photomask for the 1.0 μm to 0.35 μm rule device, which is the largest quantity in the mass production level, produces only the internal proximity effect. Therefore, even in a system limited to the internal proximity effect correction. It turns out to be extremely effective.

Since the energy contribution from other patterns can be ignored in the method of the present invention, the term of the energy contribution from other patterns in the above-mentioned equation (1) becomes zero. Therefore, since it is not necessary to take into consideration the influence of other patterns from the beginning, the calculation formula becomes simple.

In particular, the contact hole pattern is often a simple rectangle. In this case, the correction model becomes simple.

FIG. 3 shows a correction model according to the present invention.
Since there is no contribution of energy from other patterns, considering the symmetry of the figure, only two evaluation points are necessary (in the case of a square, one evaluation point is sufficient).

A desired dose is calculated by averaging the stored energy at these two locations. The accumulated energy at the point P ₁ is
It is given by the following equation (5).

[0053]

[Equation 5]

The stored energy at the point P ₂ is as follows (6)
Given by the formula.

[0055]

[Equation 6]

The average value of the accumulated energy is expressed by the following equation (7).

[0057]

[Equation 7]

Since E _{AVE in the} equation (7) must be equal to E _th , the relation of the equation (8) is established. E _AVE −E _th = 0 (8) Therefore, since the conditional equation like the equation (8) is obtained, the equation (9) is obtained by solving it.

[0059]

[Equation 8]

The dose D ₁ given to the pattern can be easily obtained by the equation (9) (in the case of a square pattern, D ₁
= Is the E _th / K _11).

When considering the influence of other patterns, complicated simultaneous equations must be solved, but by limiting the correction to the internal proximity effect, the correction can be easily performed by the present invention.

The exposure intensity K is calculated by the proximity effect function (E
Although an ID function) is subjected to multiple integration, this can be obtained only by four arithmetic calculations because an integration table is used. Therefore, also in the equation (9), it can be obtained only by simple four arithmetic operations. All the patterns can be corrected by calculating equation (9) one by one for each pattern.

According to the present invention, with respect to the pattern as shown in FIG. 12, conventionally, all of the patterns were exposed with the same dose amount, but as shown in FIG. Each can be exposed with an appropriate exposure amount.

[0064]

Embodiments of the present invention will be described below with reference to the drawings. However, it goes without saying that the present invention is not limited to the following examples.

Example 1 The system of the present invention was used to actually prepare a photomask for a memory device having a rule of 0.35 μm. In this device photomask, four types of dry plates are used.

The electron beam drawing apparatus is JBX manufactured by JEOL Ltd.
6AIII MV is used and the acceleration voltage is 20 kV. As the correction method, a high speed type using a correction table based on experimental values was selected. The square root of the area was adopted as the reference method of the correction table in the case of a rectangle.

The correction table is 4 in accordance with 4 kinds of dry plates.
I prepared a kind. The structures of the four types of dry plates are shown in FIGS.

The type (1) dry plate shown in FIG. 4 is a negative resist CM for electron beam manufactured by Tosoh Corp. as the resist 1.
S-EX (S) is used with a film thickness of 0.4 μm, and in FIG. 4, 2 is a chromium dioxide film (AR3 *) with a film thickness of 0.105 μm. 3 is synthetic quartz and has a thickness of 2.
It is 286 mm (0.09 inch).

In the type (2) dry plate of FIG. 2, the size of the substrate 4 is larger than that of the type (1), and the materials and film thicknesses of 1 and 2 are the same. Reference numeral 4 indicates the same synthetic quartz as reference numeral 3 and has a thickness of 6.35 mm (0.25 inch).
Is.

The resist indicated by reference numeral 5 in FIGS. 6 and 7 is a positive resist for electron beam manufactured by Toray Industries, Inc., and has a film thickness of 0.5 μm.
m. 2 and 3 in FIG. 6 have exactly the same structure as 2 and 3 in FIG. 7, 2 and 4 have exactly the same structure as 2 and 4 in FIG.

Four types of correction tables were prepared from the experimental data for the above four types of dry plates. The method of experiment of the correction table is designed dimensions 5.0 μm, 4.5 μm
m, 3.5 μm, 3.0 μm, 2.5 μm, 2.0 μ
m, 1.5 μm square pattern is created, and the electron beam irradiation amount given to these figures is 3.0 μC / cm ^{2 to} 5.0.
A fine setting was made between μC / cm ² . This pattern was drawn on each dry plate, the pattern of each mask was measured after the development step → post bake → denucum → etching → resist stripping, and the irradiation amount when the design dimension was achieved was taken as the value of the correction table. The values of this correction table are shown in Table 1 below.
It became like. The correction program linearly interpolated between the design dimensions to create a correction table with a pitch of 0.05 μm.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

The four types of correction tables are automatically selected according to the dry plate used by each layer of the device.

The computer used for the system is a DEC VAX Station 3100 with a MIPS value of 5.7.
Is.

In this embodiment, the exposure data is obtained according to the flow shown in FIG. 1, and the exposure is performed by this. That is, after the start I, the correction table creation II is performed according to the above procedure. Next, read 1 pattern data II
Perform I, refer to the correction table IV, add V to the correction table as appropriate, determine VI whether or not all patterns have been processed, and then return to pattern data reading III or end
VII.

Based on this system, 13 layers out of all layers were processed, and the correction time at that time was about 6 minutes per layer. Conversion speed is 22.7
It was Kbyte / sec.

Since it takes several hours to use a conventional complicated processing system, 6 minutes per layer is very fast.
It is a sufficiently practical system. In addition, the short dimension accuracy of the pattern using this system was 0.1 μm or less, and all 13 layers passed the inspection process.

When drawing without correction processing, a square pattern with a design dimension of 1.75 μm is 1.255 μm.
In addition, the pattern of 2.0 μm became 1.588 μm, but when the correction system was used, 1.75 μm was 1.78 μm and 2.0 μm was 2.03 μm, which means that the patterning is performed with high precision. It was

Example 2 In the dry plates of type (1) (FIG. 4) and type (3) (FIG. 6), correction was performed by a correction method by calculation, unlike Example 1 based on experimental values. The parameters of the EID function used in the calculation are α = 0.46 μm for type (1),
β = 2.18 μm, η = 0.48, E _th = 1.6 μC /
cm ² , in the type (3), α = 0.32 μm, β = 1.
905 μm, η = 0.46, E _th = 1.51 μC / cm
^{Was 2} .

Under the above conditions, 10 layers were corrected, but the correction time per layer was about 8 minutes.
Compared with the conventional method, the speed can be significantly improved.

This embodiment can be applied to a pattern group in which individual patterns are farther from the neighboring patterns than the backscattering radius, and the optimum electron beam can be obtained by considering only the size of each pattern. Since the irradiation amount is instantly obtained by calculation, there is no need to calculate the relationship between the size and distance of other patterns as in the conventional case, so that the time required for correction can be significantly shortened.

[0085]

INDUSTRIAL APPLICABILITY The present invention solves the above-mentioned problems of the prior art, shortens the time required for the correction for determining the exposure conditions, and makes it possible to reduce the system cost. A device can be provided.

[Brief description of drawings]

FIG. 1 is a flow chart showing steps in pattern exposure of Example 1.

FIG. 2 is an explanatory diagram of an example of exposure according to the present invention.

FIG. 3 is an explanatory diagram of correction calculation.

FIG. 4 is a diagram showing an example of a cross section of a material to be exposed in pattern exposure of Example 1 (1).

FIG. 5 is a diagram showing an example of a cross section of a material to be exposed in the pattern exposure of Example 1 (2).

FIG. 6 is a view showing an example of a cross section of a material to be exposed in the pattern exposure of Example 1 (3).

FIG. 7 is a diagram showing an example of a cross section of a material to be exposed in the pattern exposure of Example 1 (4).

FIG. 8 is a solid-state scattering model of electrons.

FIG. 9 is an explanatory diagram of a proximity effect.

FIG. 10 is an explanatory diagram of a proximity effect.

FIG. 11 is a diagram showing an influence of a proximity effect.

FIG. 12 is a diagram showing an influence of a conventional technique.

FIG. 13 is a diagram showing a dose correction method in a conventional method.

[Explanation of symbols]

I-VII pattern exposure process

Continuation of the front page (56) Reference JP-A-2-209723 (JP, A) JP-A-58-63135 (JP, A) JP-A-3-242921 (JP, A) JP-A-63-237525 (JP , A) JP 62-115830 (JP, A) JP 61-150333 (JP, A) JP 60-140060 (JP, A) JP 55-88330 (JP, A) JP 61-284921 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 1/08 G03F 7/20 504 G03F 7/20 521

Claims (7)

(57) [Claims] 1. An exposure method for exposing a pattern located in an isolated position from a neighboring pattern by irradiating the pattern with energy, wherein the dimension of the pattern to be exposed is used as a parameter, and a plurality of dimensions are determined according to each dimension. The appropriate exposure amount is obtained in advance by obtaining a distribution formula of scattering of irradiation energy and solving the distribution formula. At this time, as the distribution formula of the scattering, the following formula E = Using the energy from one's own pattern + the energy from another pattern in the neighborhood and formulating the following formula ignoring the influence of scattering on the pattern from other patterns in the neighborhood, the formula is used to calculate the exposure dose. E = energy from own pattern Solve the equation by inserting the dimensions of the pattern to be exposed,
Accordingly, so as to obtain in advance a proper exposure amount corresponding to the dimension of the pattern of the object to be exposed, at the time of exposure depending on the size of the pattern exposure method der performing exposure irradiation by the該適positive exposure led for each dimension
Then, the exposure method is characterized by performing the exposure according to the following procedure. The size of each pattern of the exposed object
Correction table based on the result of pre-determining the appropriate exposure amount according to
Create a file. Read the pattern data of the object to be exposed.
Refer to the correction table. The appropriate exposure amount of each pattern of the exposed object is obtained by the above reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount. 2. An exposure apparatus for performing exposure by irradiating energy in a pattern, comprising means for storing an appropriate exposure amount obtained in advance for a plurality of values of a pattern dimension according to each dimension. An appropriate exposure amount according to the dimension of the pattern is derived from the storage means, and exposure irradiation is performed by this exposure amount, and the previously determined and stored appropriate exposure amount is obtained by an experiment.
The method used in this experiment is a multi-size pattern.
Exposure with a finely set dose for each
Appropriate dose when the pattern is obtained and the design dimensions are met.
An exposure apparatus, which is an exposure amount . 3. An exposure apparatus for exposing a pattern in a position isolated from a neighboring pattern by irradiating the pattern with energy to obtain an appropriate exposure amount by calculating a distribution formula of scattering of irradiation energy. As the distribution formula of the scattering, the following formula for obtaining the accumulated energy E due to scattering at the evaluation point is used: E = energy from own pattern + energy from other neighboring patterns , The following equation that ignores the influence of scattering on the pattern from other patterns in the neighborhood is set as the equation for calculating the exposure amount, and E = energy from the own pattern, and the dimension of the pattern to be exposed to the equation Put in and solve,
Thus leads to proper exposure amount, and configured to perform exposure irradiated by the proper amount of exposure had conductor, and exposure by the following procedure
An exposure apparatus characterized by performing . Each part of the exposed object
Predetermined appropriate exposure amount according to the size of each turn
A correction table is created according to the result. Putter of exposed object
Read the data. Refer to the correction table. The appropriate exposure amount of each pattern of the exposed object is obtained by the above reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount. 4. An exposure apparatus for exposing a pattern in a position isolated from a neighboring pattern by irradiating the pattern with energy so that a proper exposure amount corresponding to each dimension is applied to a plurality of values of the dimension of the pattern. The distribution formula of the scatter of is calculated and solved to obtain the storage formula in advance, and the storage device for storing this is provided.
The following formula E for obtaining the product energy E = energy from own pattern + other patterns in the neighborhood
In addition to using the energy from the sensor, the equation below is established by ignoring the influence of scattering on the pattern from other patterns in the neighborhood, and the equation is used to calculate the exposure amount.
And E = energy from own pattern , solve the equation by inserting the dimension of the pattern to be exposed,
With this configuration, an appropriate exposure amount is derived and stored in the storage means, and at the time of exposure, an appropriate exposure amount according to the dimension of the pattern of the exposed object is derived from the storage means, and exposure irradiation is performed by this exposure amount. An exposure apparatus characterized in that 5. A pattern dimension value which is not stored in the storage means, an approximate value is obtained from the data stored in the storage means to obtain an appropriate exposure amount for the pattern dimension value. The exposure apparatus according to 2 or 4 . 6. A semiconductor device manufacturing method using a plurality of types of dry plates.
An exposure method for forming a photomask according to claim 1, wherein a correction table is prepared for each of the plurality of types of dry plates, and the correction table is provided for each value of a plurality of pattern dimensions.
It has an appropriate exposure amount determined in advance according to the
The appropriate exposure amount according to the above is derived by referring to the correction table.
There are, exposure radiation for the photomask formed by this exposure amount
And the appropriate exposure amount of the correction table was determined by experiment.
And the method determined by the experiment is a pattern of multiple sizes.
Exposure with a finely set dose for each
Appropriate dose when the pattern is obtained and the design dimensions are met.
An exposure method characterized in that the exposure amount is used. 7. A semiconductor device manufacturing method using a plurality of types of dry plates.
An exposure method in the case of forming a photomask, said plurality of types of dry plate each per prepare a correction table the
The correction table is available for each dimension for multiple values of the pattern dimension.
It has an appropriate exposure amount determined in advance according to the size of the pattern of the exposed object at the time of exposure for each dry plate.
The appropriate exposure amount according to the above is derived by referring to the correction table.
Exposure dose for photomask formation by this exposure amount
And the appropriate exposure amount in the correction table is set to scatter the irradiation energy.
It is calculated by obtaining the distribution formula of
The following formula E for obtaining the product energy E = energy from own pattern + other patterns in the neighborhood
For formula with use of the energy from emissions, from said other adjacent patterns of the scattering for the pattern
Formulate the following formula that ignores the influence and use the formula to calculate the exposure amount
And E = energy from the pattern of its own, solve the equation by inserting the dimension of the pattern to be exposed,
This leads to the proper exposure amount, and the derived proper exposure amount
It is configured to irradiate with multiple exposures
An exposure method comprising: Each part of the exposed object
Predetermined appropriate exposure amount according to the size of each turn
A correction table is created according to the result. Putter of exposed object
Read the data. Refer to the correction table. The appropriate exposure amount of each pattern of the exposed object is obtained by the reference, and the exposure irradiation of each pattern is performed with the appropriate exposure amount.