JP2005026527A - Method of exposure and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of exposure by which a pattern can be transferred with a desired line width by speedily and correctly grasping the variation of a line width even when the line width of a mask pattern is varied due to a stuck matter to a mask, and to provide a method of manufacturing a semiconductor device by which the pattern can be formed with a fixed line width. <P>SOLUTION: The method of exposure comprises a process of exposing by using a mask where a transmission part of beams for exposure is formed with a prescribed line width; a process of making light enter the mask to measure diffracted light; a process of obtaining the line width of the transmission part from the diffracted light; and a process of using the mask for exposure again when a difference between the line width of the transmission part from the diffracted light and the prescribed line width is within a prescribed range, and correcting exposure or washing the mask for using the mask for exposure again when the difference is not within the prescribed range. The method of manufacturing the semiconductor device includes the method of exposure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure method in a lithography process for manufacturing a semiconductor device and a method for manufacturing a semiconductor device including the exposure method of the present invention.
[0002]
[Prior art]
Conventionally, photolithography has been used to form circuit patterns and the like of semiconductor devices, but lithography capable of forming finer patterns has been proposed and developed. Such next generation lithography includes, for example, LEEPL (Low energy beam proximity projection lithography, see Patent Document 1) and PREVAIL (Projection exposure with variable axes 1 non-patent literature 1).
[0003]
In these lithography, an electron beam is used as an exposure beam, and exposure is performed through a mask (stencil mask) in which openings are formed in a predetermined pattern. A pattern is transferred onto the wafer by an electron beam that passes through the opening. In some cases, a stencil mask is used for processes other than lithography such as ion beam lithography and X-ray lithography, and ion implantation.
[0004]
[Patent Document 1]
JP 11-135423 A (Patent No. 2951947)
[Patent Document 2]
JP-A-6-275502
[Patent Document 3]
Japanese Patent Laid-Open No. 7-50248
[Patent Document 4]
US Pat. No. 5,963,329
[Non-Patent Document 1]
Hans C.I. Pfeiffer, Jpn. Appl. Phys. Vol. 34 (1995) p. 6658-6666
[0005]
[Problems to be solved by the invention]
When the stencil mask is repeatedly used for exposure, the line width and shape of the pattern change, and the resolution of the transfer pattern gradually deteriorates. This is considered to be because an organic compound such as a resist on the wafer is gasified by exposure with an electron beam or the like, reacts with moisture or gas existing in the vacuum chamber of the exposure apparatus, and deposits on the mask. In addition, particles generated from members in the vacuum chamber of the exposure apparatus when irradiated with the exposure beam may be deposited on the mask.
[0006]
In the case of a photomask used for photolithography, adhesion of foreign matter to the mask is prevented by attaching a pellicle to the mask. However, since low acceleration electrons are used in LEEPL, if a film for preventing contamination of the mask is formed in the opening of the mask, the electron beam does not pass through the opening. Alternatively, depending on the material of the film, the film is damaged by electron beam irradiation. Therefore, for example, a film like a pellicle in a photomask cannot be formed on a stencil mask used in LEEPL.
[0007]
When contaminants are deposited on the side wall of the opening of the stencil mask by exposure, the line width of the pattern becomes thin or the pattern edge roughness deteriorates. Further, contaminants deposited on portions other than the opening of the mask do not directly affect the line width of the mask pattern, but cause a phenomenon that the mask is charged during exposure (charge-up). Due to the charge-up of the mask, the electron beam incident on the mask is deflected, and as a result, the line width of the transfer pattern varies.
[0008]
As described above, when the time during which the exposure beam is irradiated onto the mask is accumulated, the line width of the transfer pattern varies. 2. Description of the Related Art Conventionally, as a method for measuring the adhesion amount of contaminants on a mask, a method is known in which an electron beam is irradiated on the mask to detect the amount of charge accumulated in the contaminants on the mask (see Patent Document 2). ). In this method, the voltage applied to the mask is changed, and the change in the position irradiated with the charged particle beam on the wafer is measured.
[0009]
There is also known a method for evaluating drawing accuracy by forming rectangular patterns of different lengths and widths sequentially as evaluation patterns on a mask and observing the shape of the drawn pattern (see Patent Document 3). In addition to the above method, a method of measuring the line width of the mask pattern by observation using a scanning electron microscope (SEM) or an atomic force microscope (AFM) is also conceivable.
[0010]
However, according to the methods described in Patent Documents 2 and 3, contaminants are further deposited on the mask during the measurement due to the electron beam irradiated to measure the amount of adhered contaminants, and the measurement accuracy deteriorates. Even when SEM observation is performed, there is a possibility that contaminants are deposited because the electron beam is irradiated. In addition, according to SEM observation, it is possible to directly measure the line width variation, but it is necessary to move the mask from the exposure apparatus to the SEM, and the chance of foreign matter adhering to the mask increases. Observation by AFM has a very low throughput and is not suitable for practical use.
[0011]
The present invention has been made in view of the above problems, and therefore the present invention can quickly and accurately grasp the amount of change in line width even when the line width of the mask pattern changes due to deposits on the mask. An object of the present invention is to provide an exposure method capable of transferring a pattern with a desired line width.
Another object of the present invention is to provide a method for manufacturing a semiconductor device that can form a pattern with a constant line width even when contaminants adhere to the mask.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an exposure method of the present invention includes a step of performing exposure using a mask in which a transmission portion of an exposure beam is formed with a predetermined line width, and light different from the exposure beam on the mask. And measuring the diffracted light, using the measured diffracted light to determine at least the line width of the transmission part, the line width determined using the diffracted light, and the predetermined And a step of performing exposure again using the mask when the difference is within a predetermined range.
[0013]
The exposure method of the present invention preferably includes a step of correcting the exposure amount and performing exposure again using the mask when the difference is not within the predetermined range. Alternatively, the exposure method of the present invention preferably includes a step of performing exposure again using the mask after cleaning the mask when the difference is not within the predetermined range.
[0014]
This makes it possible to change the exposure conditions in accordance with the amount of contaminants attached to the mask and transfer the pattern of the transmissive part with a desired line width. According to the exposure method of the present invention, contamination of the mask due to measurement of the mask pattern is prevented. Further, when the line width is measured using diffracted light, high throughput can be obtained.
[0015]
In order to achieve the above object, the exposure method of the present invention includes a time when exposure is performed using a mask in which a transmission portion of an exposure beam is formed with a predetermined line width, and a change amount of the line width. A step of obtaining a relationship, a step of performing exposure using the mask, a step of estimating a change amount of the line width using the relationship, and the estimated change amount within a predetermined range, And a step of performing exposure again using a mask.
[0016]
The exposure method of the present invention preferably includes a step of correcting the exposure amount and performing exposure again using the mask when the estimated change amount is not within the predetermined range. Alternatively, the exposure method of the present invention preferably includes a step of performing exposure again using the mask after cleaning the mask when the amount of change is not within the predetermined range.
[0017]
Thereby, it becomes possible to grasp the change in the line width of the mask pattern without using an apparatus for measuring the line width of the mask pattern in the exposure apparatus. By changing the exposure condition according to the change in the line width of the mask pattern, the pattern of the transmissive part can be transferred with a desired line width.
[0018]
In order to achieve the above object, a manufacturing method of a semiconductor device of the present invention is a manufacturing method of a semiconductor device including a lithography process for forming a resist pattern, and the lithography process includes a predetermined portion of a transmission beam of an exposure beam. A step of exposing the resist using a mask formed with a line width, a step of making light different from the exposure beam incident on the mask, measuring a diffracted light, and using the measured diffracted light, When determining at least the line width of the transmissive part, determining the difference between the line width determined using the diffracted light and the predetermined line width, and when the difference is within a predetermined range, Performing exposure again using the mask, correcting the exposure amount when the difference is not within the predetermined range, and performing exposure again using the mask, and cleaning the mask after, And performing at least one step of performing exposure again using the serial mask.
[0019]
Alternatively, the method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device including a lithography process for forming a resist pattern, and the lithography process is such that a transmission portion of an exposure beam is formed with a predetermined line width. A step of obtaining a relationship between a time during which exposure is performed using a mask and a change amount of the line width; a step of exposing a resist using the mask; and a change amount of the line width using the relationship. And when the estimated amount of change is within a predetermined range, exposure is performed again using the mask, and the estimated amount of change is not within the predetermined range. In this case, at least one of a step of correcting the exposure amount and performing the exposure again using the mask and a step of performing the exposure again using the mask after cleaning the mask is characterized.
[0020]
According to the method for manufacturing a semiconductor device of the present invention, even when contaminants accumulate on the mask due to exposure and the line width of the mask pattern changes, the amount of change in line width can be accurately grasped and the exposure condition can be determined. By appropriately correcting, it becomes possible to form a resist pattern having a certain line width. Therefore, a fine pattern can be formed on the semiconductor device with high accuracy.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an exposure method and a semiconductor device manufacturing method according to the present invention will be described below with reference to the drawings.
(Embodiment 1)
In the exposure method of the present embodiment, LEEPL which is one of electron beam transfer lithography is used.
[0022]
FIGS. 1A to 1C show the apparatus configuration of an exposure apparatus used in the exposure method of this embodiment. 1A to 1C have a configuration in which a diffracted light type line width measuring device is incorporated in a LEEPL exposure machine. The transfer chamber 1 of the LEEPL exposure machine is disposed inside the vacuum system 2. The diffracted light type line width measuring device 3 can be used either in a vacuum or in the atmosphere. As shown in FIGS. 1 (a) and 1 (c), the diffracted light type line width measuring device 3 can be used as shown in FIG. As shown in b), it may be arranged outside the vacuum system 2 or any of them.
[0023]
The load lock chamber 4 has a valve between the vacuum system 2 and is evacuated as necessary. In the load lock chamber 4, the mask can be carried into and out of the vacuum system 2 without releasing the inside of the vacuum system 2 to the atmosphere. The mask port 5 contains a mask used for exposure.
[0024]
FIG. 2 is a diagram illustrating a configuration example of the diffracted light type line width measuring device 3. As shown in FIG. 2, the white light L emitted from the light source 11 enters the stencil mask 13 perpendicularly via the optical system 12. The stencil mask 13 has an opening 14 through which an electron beam is transmitted.
[0025]
The line width of the pattern is measured in a region where the openings 14 are formed in a regular pattern (repetitive pattern) such as a line and space pattern. Another example of the repetitive pattern includes a pattern in which rectangular patterns used for contacts between conductive layers are arranged in a matrix, but other repetitive patterns may be used.
[0026]
In FIG. 2, the line width of the pattern is measured at the opening 14 of the stencil mask 13. However, the measurement of the line width of the pattern is not necessarily performed at the opening 14 that penetrates the mask. If the same unevenness as the portion 14 is formed, it can be used as a line width measurement pattern (inspection pattern). As described above, an advantage of performing the line width measurement in a portion where the exposure beam does not pass through is that the resist immediately below the inspection pattern is not exposed by the white light L for line width measurement.
[0027]
The optical system 12 includes a half mirror 15 and an objective lens 16 of an optical microscope. The light L incident perpendicularly on the stencil mask 13 from the objective lens 16 is diffracted at various orders. FIG. 2 shows the 0th to ± 2nd order diffracted light of the reflected light and the 0th to 2nd order diffracted light of the transmitted light. The zero-order diffracted light of the reflected light is detected by the detector 19 through the objective lens 16, the half mirror 15, the polarizer 17 and the spectroscope 18.
[0028]
FIG. 2 shows an example in which the polarizer 17 is disposed between the half mirror 15 and the detector 19. Instead of arranging the polarizer 17 at this position, the polarizer 17 is disposed between the light source 11 and the half mirror 15. May be arranged. By appropriately correcting the light intensity detected by the detector 19, a spectrum of diffracted light (a plot of the diffracted light intensity against the light wavelength) can be obtained.
[0029]
In the correction of the detected light intensity, for example, correction for eliminating the wavelength dependence of the light intensity of the white light L and the wavelength dependence of the sensitivity of the detector 19 is performed. The spectrum of the diffracted light includes the spectrum of the incident light, the line width and interval of the openings 14 formed in a regular pattern, the thickness of the stencil mask 13 where the openings 14 are formed, and the polarization direction of the incident light. It varies depending on the order of the diffracted light.
[0030]
As described above, since the 0th-order diffracted light is selectively detected and the spectrum of the incident light is corrected, the line width of the pattern can be obtained from the spectrum of the diffracted light. Note that the thickness of the stencil mask 13 may be regarded as a designed value or may be measured by another apparatus.
[0031]
A method of measuring the size and shape of a fine repetitive structure using diffracted light is disclosed in Patent Document 4. The configuration of the diffracted light type line width measuring instrument in the present embodiment can be changed as appropriate with reference to, for example, the method described in Patent Document 4. According to the diffracted light type line width measuring instrument having the configuration shown in FIG. 2, for example, as shown in FIG. 3, a line and space pattern in which openings are formed with a line width of 150 nm and an interval of 300 nm (pitch 1: 2), The line width of other repeated patterns can be measured with high accuracy.
[0032]
The line width measurement of the opening may be performed on either surface of the mask if the incident angle of the incident light can be regarded as vertical. However, if line width measurement is performed with the mask in the exposure posture (with the surface on which the exposure beam is incident facing up), it is not necessary to invert the mask upside down during exposure and line width measurement.
[0033]
Next, the exposure method of this embodiment will be described with reference to FIG.
Step 1 (ST1)
Prepare a new mask not used for exposure. For example, a repeating pattern as shown in FIG. 3 is formed on the mask as an inspection pattern.
Step 2 (ST2)
The line width of the inspection pattern on the mask is measured using a diffracted light type line width measuring device. The value obtained at this time is ML₀[Nm].
[0034]
Step 3 (ST3)
In order to obtain a reference exposure amount (referred to as a reference exposure amount), an exposure experiment is performed. In this exposure experiment, the mask pattern line width ML is changed by changing the exposure amount on the resist on the wafer.₀An inspection pattern of [nm] is exposed. Here, the reference exposure amount is the line width ML of the mask pattern measured in Step 2₀[Nm] is the same line width (resist pattern line width ML₀[Nm]) exposure amount E₀[ΜC / cm²]. In an exposure experiment at each exposure amount, a new mask that is not used for exposure is used.
[0035]
Step 4 (ST4)
The line width (transfer line width RL) of the pattern transferred to the resist by the exposure in step 3 is measured. For example, SEM is used to measure the transfer line width, but a diffracted light type line width measuring device can also be used.
[0036]
Step 5 (ST5)
From the exposure in step 3 and the measurement of the transfer line width in step 4, the reference exposure amount can be obtained. Further, for example, the relationship between the exposure amount and the transfer line width as shown in FIG. 5 can be obtained. In the exposure experiment of Step 3, the exposure amount is the reference exposure amount E.₀[ΜC / cm²] To about twice as large as. As shown in FIG. 5, the exposure amount is the reference exposure amount E.₀In the range up to about 2 times, the transfer line width RL is substantially proportional to the exposure amount.
[0037]
In FIG. 5, the reference exposure amount E₀Transfer line width at L₀, Twice the standard exposure (2E₀) Transfer line width at L₁Then the slope of the graph is (L₁-L₀) / E₀It is. Therefore, the transfer line width at a certain exposure amount can be calculated from the slope of the graph. The exposure conditions are set by the above steps 1 to 5, and the exposure for actual device fabrication is performed in the next step 6 and subsequent steps.
[0038]
Step 6 (ST6)
Before the exposure, the line width of the inspection pattern on the mask is measured using a diffracted light type line width measuring device. The value obtained at this time is ML₁[Nm]. Since the mask is normally used repeatedly for exposure, not only after measuring and calculating various values in Steps 2 to 5, but also after several exposures of the mask and before the next exposure The length measurement in step 6 is performed.
[0039]
Step 7 (ST7)
Step 6 mask pattern line width ML₁[Nm] and mask pattern line width ML in step 2₀[Nm] difference ΔML (= ML₀-ML₁) And is compared with a constant Cmax. The line width fluctuation amount ΔML can be regarded as the accumulated amount of contaminants. Cmax is the maximum value of the allowable amount of line width variation, and is set in advance according to the performance required for the device.
[0040]
Step 8 (ST8)
If the line width variation amount ΔML is equal to or smaller than Cmax in step 7, the exposure amount is corrected. Mask pattern line width is ML₀In the case of [nm], the relationship between the exposure amount and the transfer line width is as shown in FIG. 5, but since the line width variation ΔML is small, the mask pattern line width is ML.₁In the case of [nm], it can be considered that the same relationship holds. That is, referring to the result of step 5, the transfer line width RL is set to ML using the slope of the graph of FIG.₀Exposure amount E₁The exposure amount E₁Is the corrected exposure amount.
[0041]
Step 9 (ST9)
The pattern on the mask is exposed to n wafers. The number n of wafers to be exposed is set in advance within a range in which the line width variation ΔML is negligible.
[0042]
Step 10 (ST10)
Select whether to continue exposure. When the exposure is continued, the mask is conveyed to the diffracted light type line width measuring device, and the steps after the mask pattern line width measurement in step 6 are performed. If the exposure is not continued, the series of steps is terminated.
[0043]
Step 11 (ST11)
If the line width variation ΔML exceeds Cmax in step 7, the mask is cleaned. Thereafter, the steps after the mask pattern line width measurement in step 6 are performed.
[0044]
The manufacturing method of the semiconductor device of this embodiment includes the lithography process by the above exposure method. According to the exposure method of the present embodiment, the line width measurement of the mask pattern can be performed in real time with exposure in the exposure apparatus. Therefore, the exposure amount can be corrected and the mask can be cleaned before the deposit of contaminants on the mask has a fatal effect on the line width of the resist pattern.
[0045]
Further, for example, even when the amount of accumulated contaminants per unit time changes due to a change in the degree of vacuum in the transfer chamber or exposure conditions, the accumulated amount of contaminants can be accurately grasped. According to the exposure method of the present embodiment, a change in the line width of a mask pattern can be corrected according to exposure conditions, and a pattern having a desired line width can be transferred.
[0046]
Further, since visible light is used instead of an electron beam for measuring the line width of the mask pattern, generation of particles is suppressed, and contaminants attached to the mask are reduced. Further, since the mask is not transported to another apparatus outside the exposure apparatus for the purpose of measuring the amount of contaminants deposited on the mask, the mask transport path is shortened, and the contamination is reduced.
[0047]
(Embodiment 2)
This embodiment is also an example of exposure by LEEPL and a method for manufacturing a semiconductor device. Hereinafter, the exposure method of this embodiment will be described with reference to FIG.
Step 1 (ST1)
Prepare a new mask not used for exposure.
[0048]
Step 2 (ST2)
In order to obtain a reference exposure amount (referred to as a reference exposure amount), an exposure experiment is performed. A resist is applied on the wafer in advance. For example, a negative resist is applied on an 8-inch silicon wafer. Here, the reference exposure amount is an exposure amount (B [μC / cm) that resolves with the same line width (resist pattern line width A [nm]) of the mask pattern P (width [A] nm).²]. ). For example, an exposure amount at which a mask pattern P having a line width of 100 nm is resolved by a resist pattern having a line width of 100 nm is set as a reference exposure amount. Also, the accumulated exposure time at this time is 0 [hour]. Here, the cumulative exposure time is the total time for which the mask is used for exposure.
[0049]
Step 3 (ST3)
The line width (transfer line width RL) of the pattern transferred to the resist by the exposure in step 2 is measured. For example, SEM is used to measure the transfer line width, but a diffracted light type line width measuring device can also be used.
Step 4 (ST4)
From the exposure in step 2 and the measurement of the transfer line width in step 3, the reference exposure amount is obtained.
[0050]
Step 5 (ST5)
Next, the mask pattern P is set to the reference exposure amount B [μC / cm.²] To repeat exposure.
Step 6 (ST6)
When the accumulated exposure time is T [time], the line width (A ′ [nm]) of the pattern transferred to the resist by the exposure in step 5 is measured. The transfer line width is measured in the same manner as in Step 3.
[0051]
Step 7 (ST7)
From the repeated exposure in step 5 and the measurement of the transfer line width in step 6, for example, the relationship between the cumulative exposure time T [time] and the transfer line width A ′ [nm] as shown in FIG. 7 can be obtained. As shown in FIG. 7, as the cumulative exposure time increases, the transfer line width decreases linearly. The slope of the graph of FIG. 7 is (A−A ′) / T.
[0052]
Step 8 (ST8)
A mask pattern P having a line width A [nm] is defined as a reference exposure amount B [μC / cm²] Larger exposure dose B ′ [μC / cm²In order to obtain the line width (A ″ [nm]) of the resist pattern that is resolved when exposed in step 1], an exposure experiment is performed. In other words, in the exposure experiment in Step 8, the exposure dose B ′ [μC / cm²] Is the standard exposure dose B [μC / cm²] To about twice as large as.
[0053]
Step 9 (ST9)
The line width A ″ [nm] of the resist pattern resolved by the exposure in step 8 is measured in the same manner as in step 3. The measurement of the resist pattern line width A ″ [nm] at each exposure amount is all. A mask having a cumulative exposure time of 0 [hour] is used.
[0054]
Step 10 (ST10)
From the exposure in step 8 and the measurement of the transfer line width in step 9, for example, the relationship between the exposure amount and the transfer line width as shown in FIG. 8 can be obtained. As shown in FIG. 8, in the range where the exposure amount is up to about twice the reference exposure amount, the transfer line width is substantially proportional to the exposure amount. The slope of the graph in FIG. 8 is (A ″ −A) / (B′−B). With the above steps, conditions for correcting the exposure amount are obtained.
[0055]
Step 11 (ST11)
The reference exposure dose B [μC / cm] is applied to the mask prepared in step 1 and having no contaminants deposited thereon.²], Exposure for device fabrication is performed.
[0056]
Step 12 (ST12)
The relationship between the cumulative exposure time obtained in step 7 and the transfer line width is matched with the relationship between the exposure amount obtained in step 10 and the transfer line width, and the exposure amount is corrected so as to compensate for the decrease in the transfer line width. That is, after obtaining the transfer line width reduction amount in a certain cumulative exposure time from FIG. 7, this transfer line width change amount is applied to FIG. 8 to obtain the same transfer line width as the mask pattern line width. An amount is obtained, and this is set as a corrected exposure amount.
[0057]
Step 13 (ST13)
The accumulated exposure time is compared with a preset threshold value D [time]. If the accumulated exposure time is equal to or less than the threshold value D [time], the exposure in step 11 is performed with the exposure amount corrected in step 12. Here, the threshold value D [time] is an accumulated exposure time in which the transfer line width cannot be reduced within the allowable range even by increasing the exposure amount.
[0058]
Step 14 (ST14)
If the accumulated exposure time exceeds the threshold value D [time] in step 13, it is selected in step 14 whether to continue exposure.
Step 15 (ST15)
When the exposure is continued, the mask is washed and the steps after step 11 are performed. If the exposure is not continued in step 14, the series of steps is terminated.
[0059]
The manufacturing method of the semiconductor device of this embodiment includes the lithography process by the above exposure method. According to the exposure method of the present embodiment described above, when the degree of vacuum in the transfer chamber, the exposure conditions, etc. are constant, the amount of contaminants deposited on the mask can be grasped without actually measuring the mask pattern line width. it can. Therefore, the exposure amount can be corrected to prevent the transfer line width from changing. In addition, it is possible to accurately grasp the timing of mask cleaning.
[0060]
The embodiments of the exposure method and semiconductor device manufacturing method of the present invention are not limited to the above description. The present invention can be applied to lithography other than LEEPL, such as lithography using other electron beam transfer lithography, ion beam lithography, X-ray lithography, and masks other than stencil masks. In addition, various modifications can be made without departing from the scope of the present invention.
[0061]
【The invention's effect】
According to the exposure method of the present invention, even when the line width of the mask pattern changes due to the deposit on the mask, the amount of change in the line width can be quickly and accurately grasped, and the pattern can be transferred with the desired line width. it can. According to the method for manufacturing a semiconductor device of the present invention, a pattern can be formed with a constant line width even when contaminants adhere to the mask.
[Brief description of the drawings]
FIG. 1A to FIG. 1C are diagrams showing a configuration example of an apparatus used in an exposure method of the present invention.
FIG. 2 is a view showing an optical system used for measuring a line width of a mask pattern according to the exposure method of Embodiment 1 of the present invention.
FIG. 3 shows an example of a pattern used for measurement of diffracted light according to the exposure method of Embodiment 1 of the present invention.
FIG. 4 is a flowchart showing an exposure method according to the first embodiment of the present invention.
FIG. 5 is a graph showing a relationship between an exposure amount and a transfer line width in the exposure method according to the first embodiment of the present invention.
FIG. 6 is a flowchart showing an exposure method according to the second embodiment of the present invention.
FIG. 7 is a graph showing a relationship between an accumulated exposure time and a transfer line width according to the second embodiment of the present invention.
FIG. 8 is a graph showing a relationship between an exposure amount and a transfer line width according to the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Transfer chamber, 2 ... Vacuum system, 3 ... Diffraction light type line width measuring device, 11 ... Light source, 12 ... Optical system, 13 ... Stencil mask, 14 ... Opening, 15 ... Half mirror, 16 ... Objective lens, 17 ... polarizer, 18 ... spectrometer, 19 ... detector.

Claims (14)

A step of performing exposure using a mask in which a transmission part of an exposure beam is formed with a predetermined line width;
Making the different light from the exposure beam incident on the mask and measuring the diffracted light;
Using the measured diffracted light to determine at least the line width of the transmission part;
Obtaining the difference between the line width obtained using the diffracted light and the predetermined line width;
And exposing again using the mask when the difference is within a predetermined range. The exposure method according to claim 1, further comprising: correcting the exposure amount and performing exposure again using the mask when the difference is not within the predetermined range. The exposure method according to claim 1, further comprising a step of cleaning the mask and performing exposure again using the mask when the difference is not within the predetermined range. The exposure method according to claim 1, wherein the predetermined range is determined based on a line width of a pattern onto which the transmission part is transferred by the exposure. The exposure method according to claim 1, wherein the transmission part is an opening. The exposure method according to claim 1, wherein the light is incident on a portion where the transmission portions are regularly arranged, and the diffracted light is measured. The exposure method according to claim 1, wherein the light is incident on a portion where there is no transmissive portion and irregularities are regularly formed on the surface, and the diffracted light is measured. A step of obtaining a relationship between a time during which exposure is performed using a mask in which a transmission portion of an exposure beam is formed with a predetermined line width and a change amount of the line width;
Performing an exposure using the mask;
Estimating the amount of change in the line width using the relationship;
And exposing again using the mask when the estimated amount of change is within a predetermined range. 9. The exposure method according to claim 8, further comprising a step of correcting the exposure amount and performing exposure again using the mask when the estimated change amount is not within the predetermined range. 9. The exposure method according to claim 8, further comprising the step of performing exposure again using the mask after cleaning the mask when the amount of change is not within the predetermined range. The exposure method according to claim 8, wherein the predetermined range is determined based on a line width of a pattern onto which the transmission part is transferred by the exposure. The exposure method according to claim 8, wherein the transmissive portion is an opening. A method of manufacturing a semiconductor device including a lithography process for forming a resist pattern,
The lithography step is a step of exposing a resist using a mask in which a transmission part of an exposure beam is formed with a predetermined line width;
Making the different light from the exposure beam incident on the mask and measuring the diffracted light;
Using the measured diffracted light to determine at least the line width of the transmission part;
Obtaining the difference between the line width obtained using the diffracted light and the predetermined line width;
Performing the exposure again using the mask when the difference is within a predetermined range,
When the difference is not within the predetermined range, a step of correcting the exposure amount and performing the exposure again using the mask, and a step of cleaning the mask and then performing the exposure again using the mask A manufacturing method of a semiconductor device which performs at least one. A method of manufacturing a semiconductor device including a lithography process for forming a resist pattern,
The lithography step is a step of obtaining a relationship between a time during which exposure is performed using a mask in which a transmission part of an exposure beam is formed with a predetermined line width and a change amount of the line width;
Exposing the resist using the mask;
Estimating the amount of change in the line width using the relationship;
A step of performing exposure again using the mask when the estimated amount of change is within a predetermined range;
When the estimated amount of change is not within the predetermined range, correcting the exposure amount and performing exposure again using the mask; cleaning the mask and then exposing again using the mask A method for manufacturing a semiconductor device, which performs at least one of the steps of performing the steps.

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