JPWO2007096949A1 - EXPOSURE APPARATUS, EXPOSURE METHOD, AND ELECTRONIC DEVICE MANUFACTURING METHOD - Google Patents

Abstract

An exposure apparatus, a correction method therefor, and a method for manufacturing an electronic apparatus that have good correction follow-up performance for changes in atmospheric pressure. A barometer 22 that measures atmospheric pressure P, a lens barrel 14 that is sealed inside, a lens system 15 that is housed in the lens barrel 14, and a pressure adjusting unit that adjusts the pressure in the lens barrel 14. 16, the stage 18 on which the substrate 100 is placed and which can be moved up and down, and the atmospheric pressure P measured by the barometer 22 are taken in a predetermined sampling period to calculate the atmospheric pressure fluctuation amount ΔP / t per unit time, Based on the calculated atmospheric pressure fluctuation amount ΔP / t and the captured atmospheric pressure P, the pressure control unit 16 is controlled to correct the magnification of the lens system 15 accompanying the atmospheric pressure fluctuation, or the stage 18 is moved up and down. Thus, the exposure apparatus has a control unit 21 that corrects the defocus of the lens system 15 due to the atmospheric pressure fluctuation. [Selection] Figure 1

Description

  The present invention relates to an exposure apparatus, an exposure method, and a method for manufacturing a semi-electronic device.

  In the manufacturing process of an electronic device such as an LSI or a liquid crystal panel, an exposure step of exposing a pattern to a photoresist is performed using an exposure device such as a stepper or a scanner. The exposure apparatus has a lens system composed of a plurality of lenses in the lens barrel, but the relative distance of each lens fluctuates or the air density fluctuates due to fluctuations in atmospheric pressure, so magnification, focal length, etc. The optical characteristics of the lens system fluctuate from the reference value. Therefore, in the exposure apparatus, it is necessary to return the magnification to the reference value by correcting the magnification fluctuation and defocus, and to make the defocus zero.

  In patent documents 1-3, such correction | amendment is performed based on the value of atmospheric pressure.

  Moreover, in patent document 4, the atmospheric | air pressure in a lens-barrel is estimated from the atmospheric pressure measured with the barometer, and said correction | amendment is performed using the estimated value.

However, if only the atmospheric pressure value is used as in Patent Documents 1 to 3, there is an inconvenience that the followability of the correction is deteriorated when the atmospheric pressure fluctuation is large, such as when a typhoon passes.
Japanese Utility Model Publication No. 63-178320 Japanese Utility Model Publication No. 8-21531 JP 2003-59807 A Japanese Patent No. 3387861

  SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus, a correction method therefor, and a method for manufacturing an electronic apparatus, which have good correction followability with respect to fluctuations in atmospheric pressure.

  According to one aspect of the present invention, a barometer that measures atmospheric pressure, a lens barrel that is sealed inside, a lens system that is housed in the lens barrel, and a pressure adjustment that adjusts the pressure in the lens barrel Part, a stage on which a substrate can be placed and moved up and down, an output value of the barometer is taken at a predetermined sampling period to calculate an atmospheric pressure fluctuation amount per unit time, and the calculated atmospheric pressure fluctuation amount and the Based on the taken-in atmospheric pressure, the pressure adjusting unit is controlled to correct the magnification of the lens system accompanying atmospheric pressure fluctuations, or the stage is raised and lowered to focus the lens system accompanying atmospheric pressure fluctuations. An exposure apparatus having a control unit that corrects the deviation is provided.

  According to the present invention, since the magnification correction and the defocus correction are performed based not only on the atmospheric pressure but also on the atmospheric pressure fluctuation amount, the correction result follows the atmospheric pressure fluctuation satisfactorily. Even when the ratio is large, it is possible to sufficiently reduce the magnification fluctuation and the defocus.

  According to another aspect of the present invention, the step of calculating the atmospheric pressure fluctuation amount per unit time by taking the output value of the barometer at a predetermined sampling period, and the optical characteristics of the lens system accompanying the atmospheric pressure fluctuation A correction step for correcting the change, and the correction step adjusts the pressure in the lens barrel sealed inside based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure. The step of correcting the magnification of the lens system housed in the lens barrel, or the stage on which the substrate is placed is moved up and down based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure. An exposure apparatus correction method including any one of the steps of correcting the defocus of the lens system is provided.

  According to still another aspect of the present invention, there are provided a step of forming a film on a substrate, a step of applying a photoresist on the film, and a change in optical characteristics of the exposure apparatus due to atmospheric pressure fluctuations. A step of correcting, a step of exposing the photoresist using the exposure apparatus after the correction, a step of developing the photoresist after the exposure to form a resist pattern, and using the resist pattern as a mask The step of etching the film and using the film left unetched as a device pattern and the step of removing the resist pattern, and correcting the change in the optical characteristics of the exposure apparatus includes: The atmospheric pressure fluctuation amount per unit time is calculated by taking in the output value of the meter at a predetermined sampling period, and based on the calculated atmospheric pressure fluctuation quantity and the taken-in atmospheric pressure. Then, the pressure in the lens barrel sealed inside is adjusted to correct the magnification of the lens system housed in the lens barrel, or the calculated atmospheric pressure fluctuation amount and the captured atmospheric pressure are corrected. Based on the above, there is provided a method for manufacturing an electronic device, which is performed by raising and lowering a stage on which the substrate is placed to correct defocusing of the lens system.

  According to the present invention, in the step of correcting the change in the optical characteristics of the exposure apparatus, the correction is performed based on not only the atmospheric pressure but also the atmospheric pressure fluctuation amount. Therefore, the correction result follows the atmospheric pressure fluctuation satisfactorily, and the line width of the device pattern can be easily kept within the standard value even when the atmospheric pressure fluctuation is large.

FIG. 1 is a block diagram of an exposure apparatus used in the embodiment of the present invention. FIG. 2 is a diagram schematically showing a first pressure adjustment table used in the embodiment of the present invention. FIG. 3 is a diagram schematically showing a second pressure adjustment table used in the embodiment of the present invention. FIG. 4 is a diagram schematically showing a first stage adjustment table used in the embodiment of the present invention. FIG. 5 is a diagram schematically showing a second stage adjustment table used in the embodiment of the present invention. FIG. 6 is a flowchart showing a correction method of the exposure apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart showing details of the step of correcting the magnification of the lens system in the embodiment of the present invention. FIG. 8 is a flowchart showing details of the step of correcting the defocus of the lens system in the embodiment of the present invention. FIG. 9 is a graph obtained by investigating how the defocus changes with time unless the correction term K ₄ (ΔP / t) is used when the atmospheric pressure changes with time. FIG. 10 is a graph obtained by investigating how the defocus changes with the change in atmospheric pressure when the correction term K ₄ (ΔP / t) is used as in the embodiment of the present invention. It is. FIG. 11 is a diagram showing the value of the correction term K ₄ (ΔP / t) used in the investigation of FIG. FIG. 12 is a diagram showing the value of the correction term K ₂ (ΔP / t) that can be used in the embodiment of the present invention. 13A and 13B are cross-sectional views (part 1) in the middle of manufacturing the electronic device according to the embodiment of the present invention. 14A and 14B are cross-sectional views (part 2) in the middle of manufacturing the electronic device according to the embodiment of the present invention. 15A and 15B are cross-sectional views (part 3) in the middle of manufacturing the electronic device according to the embodiment of the present invention. FIG. 16 is a cross-sectional view (No. 4) of the electronic device according to the embodiment of the present invention in the middle of manufacture.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(1) Description of Exposure Apparatus FIG. 1 is a block diagram of an exposure apparatus used in this embodiment.

  This exposure apparatus is a stepper and includes a housing 11, a control unit 21, and a barometer 22.

  Among these, a light source 12, a reticle 13, a lens barrel 14, and a stage 18 are arranged in the housing 11.

  The lens barrel 14 is hermetically sealed, and a lens system 15 including a plurality of lenses 15 a is accommodated in the lens barrel 14. In addition, the lens barrel 14 is provided with a pressure adjusting unit 16 for adjusting the internal pressure and a pressure measuring unit 17 for measuring the pressure.

  On the other hand, the substrate 100 is placed on the stage 18. The stage 18 includes an elevating mechanism 19 that elevates the substrate 100 in the illustrated direction toward the lens barrel 14, and further includes a distance measuring unit 20 for measuring the elevating distance.

  The control unit 21 includes a pressure controller 23, a storage unit 25, and a focus controller 24.

  The pressure controller 23 has a function of taking the atmospheric pressure value (P) output from the barometer 22 at a predetermined sampling period, for example, a period of 30 minutes, and calculating an atmospheric pressure fluctuation amount (ΔP / t) per unit time. Have. Then, based on a pressure adjustment table, an atmospheric pressure value (P), and an atmospheric pressure fluctuation amount (ΔP / t), which will be described later, stored in the storage unit 25, the pressure controller 23 sends the pressure adjustment amount to the pressure adjustment unit 16. Instruct.

  The pressure in the lens barrel 14 after adjustment is measured by the pressure measurement unit 17, and the measurement result is fed back to the pressure controller 23. Thereby, the pressure in the lens barrel 14 is controlled by a closed loop system.

  Similarly to the pressure controller 23, the focus controller 24 also captures the atmospheric pressure value (P) at a predetermined sampling period of about 30 minutes and calculates the atmospheric pressure fluctuation amount (ΔP / t) per unit time. Have Then, the focus controller 24 instructs the moving mechanism 19 to move up and down based on a stage adjustment table, which will be described later, stored in the storage unit 25, an atmospheric pressure value (P), and an atmospheric pressure fluctuation amount (ΔP / t). To do.

  The elevation amount is measured by the distance measuring unit 20, and the measured value is fed back to the focus controller 24. Thereby, the raising / lowering amount of the stage 18 is controlled by a closed loop system.

  In this exposure apparatus, exposure light emitted from the light source 12 passes through the reticle 13 and the lens system 15, and an exposure pattern (not shown) formed on the reticle 13 is reduced and projected onto the substrate 100.

  However, since the optical characteristics of the lens system 15 such as the magnification and the focal length vary depending on the atmospheric pressure, it is necessary to correct the optical characteristics according to the atmospheric pressure.

  For example, the variation in magnification is caused by a change in air density or a change in the relative distance between the lenses 15a, and can be corrected by adjusting the pressure in the lens barrel 14.

  On the other hand, the defocus due to the change in focal length can be corrected by moving the stage 18 up and down so that the focal point of the optical system 15 is on the surface of the substrate 100.

  These corrections are performed using various tables stored in the storage unit 25.

  2 to 5 are diagrams schematically showing tables used for the above correction.

FIG. 2 is a diagram schematically showing the first pressure adjustment table 31. As shown in this figure, the first pressure adjustment table 31 is composed of a pair of the first pressure adjustment amount K ₁ and the atmospheric pressure P (hPa).

The first pressure adjustment amount K ₁ is necessary to make the magnification of the lens system 15 equal to the magnification at the reference atmospheric pressure (for example, 1000 hPa) under the condition that the atmospheric pressure fluctuation amount ΔP / t is zero. This is the amount of pressure adjustment in the lens barrel 14. For example, in the illustrated example, when the atmospheric pressure fluctuation amount ΔP / t is zero and the atmospheric pressure P is 1010 hPa, the pressure adjustment amount in the lens barrel 14 is set to +1, which is the same as the case of the reference atmospheric pressure (1000 hPa) pressure. The magnification can be set.

  The pressure adjustment amount is measured in a control unit, and the unit of pressure (hPa) may not be adopted as the unit.

On the other hand, FIG. 3 is a diagram schematically showing the second pressure adjustment table 32. The second pressure adjustment table 32 includes a pair of a second pressure adjustment amount K ₂ and an atmospheric pressure fluctuation amount ΔP / t (hPa / hour) per unit time.

The second pressure adjustment amount K ₂ is used together with the first pressure adjustment amount K _{1 in} order to obtain the same magnification as when the atmospheric pressure fluctuation amount ΔP / t is zero when the atmospheric pressure fluctuation amount ΔP / t is not zero. This is a necessary pressure adjustment amount in the lens barrel 14.

FIG. 4 is a diagram schematically showing the first stage adjustment table 41. As shown in this figure, the first stage adjustment table 41 is composed of a pair of the first stage movement amount K ₃ and the atmospheric pressure P (hPa).

The first stage movement amount K ₃ is the amount of elevation of the stage 18 that is required to make the lens system 15 out of focus under the condition that the atmospheric pressure fluctuation amount ΔP / t is zero. For example, in the example shown in the figure, when the atmospheric pressure fluctuation amount ΔP / t is zero and the atmospheric pressure P is 1020 hPa, defocusing can be made zero by setting the lift of the stage 18 to +2.

  The stage movement amount is measured in a control unit, and the unit of length may not be adopted as the unit.

On the other hand, FIG. 5 is a diagram schematically showing the second stage adjustment table 42. The second stage adjustment table 42 includes a pair of a second stage movement amount K ₄ and an atmospheric pressure fluctuation amount ΔP / t (hPa / hour) per unit time.

The second stage movement amount K ₄ is the amount of elevation of the stage 18 that is necessary together with the first stage movement amount K ₃ in order to make the focus shift zero when the atmospheric pressure fluctuation amount ΔP / t is not zero.

  Each table shown in FIG. 2 to FIG. 5 is obtained by measuring the defocus and magnification fluctuation in the exposure apparatus shown in FIG. 1 while the operator monitors the atmospheric pressure P and the atmospheric pressure fluctuation amount ΔP / t. It is produced individually in the exposure apparatus.

  Using these tables, in this embodiment, the exposure apparatus is corrected as follows.

(2) Exposure Apparatus Correction Method FIG. 6 is a flowchart showing the exposure apparatus correction method.

  In the first step S1, the control unit 21 takes in the atmospheric pressure value P output from the barometer 22 at a predetermined sampling period, for example, a period of 30 minutes, and calculates the atmospheric pressure fluctuation amount ΔP / t per unit time. The pressure controller 23 or the focus controller 24 calculates the atmospheric pressure fluctuation amount ΔP / t.

  In the next step S2, it is determined whether or not the atmospheric pressure fluctuation amount ΔP / t exceeds an upper limit value, for example, 5 hPa / hour. As the upper limit at this time, for example, it is preferable to adopt the maximum value of the atmospheric pressure fluctuation amount ΔP / t that has been experienced so far in the factory where the exposure apparatus is installed. This is because it is unknown how the magnification fluctuation and defocus in the exposure apparatus behave when the atmospheric pressure fluctuation amount ΔP / t exceeding the maximum value.

  Therefore, if it is determined in step S2 that the atmospheric pressure fluctuation amount ΔP / t exceeds the upper limit (YES), the process proceeds to step S6 to interlock the exposure apparatus, and the substrate to be exposed next. Stop accepting 10. When exposure is being performed on the substrate 100 in the exposure apparatus, the above-described interlock is applied after the exposure is completed.

  Thereafter, the process proceeds to step S7, where an alarm such as a warning sound or a warning lamp is issued to notify the operator that the atmospheric pressure fluctuation amount ΔP / t has exceeded the upper limit value.

  On the other hand, when it is determined that the atmospheric pressure fluctuation amount ΔP / t does not exceed the upper limit (NO), the process proceeds to the correction step S3.

  The correction step S3 includes a step S4 for correcting the magnification of the lens system 15 and a step S5 for correcting the defocus of the lens system 15.

  In step S4, the pressure in the lens barrel 14 is adjusted to obtain the same magnification as when the atmospheric pressure P is the standard atmospheric pressure (for example, 1000 hPa) and the atmospheric pressure fluctuation amount ΔP / t is zero.

  On the other hand, in step S5, the amount of defocus is made zero by adjusting the lift of the stage 18.

  FIG. 7 is a flowchart showing details of step S4 for correcting the magnification of the lens system 15.

In the first step S10 of FIG. 7, the pressure controller 23 refers to the first pressure adjustment table 31 (FIG. 2) and obtains the _first pressure adjustment amount K ₁ (P) corresponding to the current atmospheric pressure P. To do.

Next, proceeding to step S11, the pressure controller 23 refers to the second pressure adjustment table 32 (FIG. 3), and the second pressure adjustment corresponding to the atmospheric pressure fluctuation amount ΔP / t obtained in step S1. Get the quantity K ₂ (ΔP / t).

Subsequently, the process proceeds to step S12, the pressure LP ₂ to be applied to the lens barrel 14 obtained by the following equation (1).

LP ₂ = P + K ₁ (P) + K ₂ (ΔP / t) (1)
In the equation (1), an increase from the atmospheric pressure P, that is, K ₁ (P) + K ₂ (ΔP / t) is a pressure adjustment amount to be applied to the lens barrel 14.

The pressure controller 23 controls the pressure adjustment unit 16 so that the pressure in the lens barrel 14 is adjusted by this pressure adjustment amount K ₁ (P) + K ₂ (ΔP / t), and thereby the magnification associated with the atmospheric pressure fluctuation. Make corrections.

  On the other hand, FIG. 8 is a flowchart showing details of step S5 for correcting the defocus of the lens system 15.

In the first step S15 of FIG. 8, the focus controller 24 refers to the first stage adjustment table 41 (FIG. 4) and acquires the first stage movement amount K ₃ (P) corresponding to the current atmospheric pressure P. .

Next, the process proceeds to step S16, where the focus controller 24 refers to the second stage adjustment table 42 (FIG. 5), and the second stage movement amount K corresponding to the atmospheric pressure fluctuation amount ΔP / t obtained in step S1. _{4 Get} (ΔP / t).

Subsequently, the process proceeds to step S17, and the lift FO ₂ of the stage 18 necessary to make the defocus zero is obtained by the following equation (2).

FO ₂ = K ₃ (P) + K ₄ (ΔP / t) (2)
The focus controller 24 controls the elevating mechanism 19 so that the stage 18 moves up and down by this FO ₂ , so that the defocus due to the atmospheric pressure fluctuation becomes zero.

  Thus, the main steps of the correction step S3 in FIG. 6 are completed, and the exposure apparatus according to the present embodiment is corrected.

By the way, the above equations (1) and (2) have correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) corresponding to the atmospheric pressure fluctuation amount ΔP / t.

On the other hand, as in Patent Documents 1 to 3, it is considered that correction is performed by dropping these correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) from Equations (1) and (2). It is done.

FIG. 9 shows how the defocus changes with time when the correction term K ₄ (ΔP / t) is dropped as described above from Equation (2) when the atmospheric pressure changes with time. It is the graph obtained.

As shown in FIG. 9, if the change in atmospheric pressure is moderate (about 1 hPa / hour), sufficient correction can be performed even if the correction term K ₄ (ΔP / t) is reduced. For example, if the atmospheric pressure fluctuation amount ΔP / t is within 2 hPa / hour, the amount of defocus, that is, the amount of deviation between the focal point of the lens system 14 and the substrate 100 is 0.05 μm or less. This value is not a problem because it is within the range of defocus that can be controlled by the exposure apparatus.

However, an actual change in atmospheric pressure varies, when typhoon or, since the pressure distribution of the wintry of Seikototei is the atmospheric pressure variation [Delta] P / t becomes large when collapse suddenly, the above correction term K ₄ ([Delta] P / If t) is dropped, the temporal followability of the correction will be poor. According to FIG. 9, when the correction term K ₄ (ΔP / t) is dropped, the correction follows up to the atmospheric pressure fluctuation amount ΔP / t up to about 2 hPa / hour, and beyond that, the atmospheric pressure fluctuation amount ΔP The followability deteriorates as / t increases. In particular, when a high-speed typhoon passes, the atmospheric pressure fluctuation amount ΔP / t may reach 4 to 5 hPa / hour, and in this case, the error in correcting the defocus becomes large.

  As is apparent from FIG. 9, when the atmospheric pressure fluctuation amount ΔP / t is about 3 hPa / hour, the defocus is about 0.1 μm. If exposure is performed on a layer having a severe focus margin in this state, patterning defects such as shape defects and line width defects occur in the layer. Further, it can be seen that when the atmospheric pressure fluctuation amount ΔP / t becomes 4 hPa / hour, the defocus becomes 0.1 to 0.2 μm.

Regarding the fluctuation of the magnification, if the atmospheric pressure fluctuation amount ΔP / t is within 2 hPa / hour, the magnification fluctuation can be suppressed to about 1 ppm even if the correction term K ₂ (ΔP / t) is dropped from the equation (1). This is known from the inventor's experience. This value is not a value that causes a particular problem when positioning the substrate 100 and the exposure apparatus.

However, when the atmospheric pressure fluctuation amount ΔP / t is about 3 hPa / hour with the correction term K ₂ (ΔP / t) being reduced, the magnification fluctuation is about 2 ppm, and the alignment margin between the substrate 100 and the exposure apparatus is severe. In the exposure of a layer, there arises a disadvantage that a leakage current or the like increases in the layer after patterning. Further, when the atmospheric pressure fluctuation amount ΔP / t is 4 hPa / hour or more, the magnification fluctuation becomes 2 to 3 ppm, which may cause a considerable defect.

As described above, when the correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) corresponding to the atmospheric pressure fluctuation amount ΔP / t are dropped from the equations (1) and (2), the defocus correction and magnification are reduced. The correction cannot follow the atmospheric pressure fluctuation.

On the other hand, in the present embodiment, correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) are added to equations (1) and (2), so that correction following atmospheric pressure fluctuation is performed. Can do.

FIG. 10 is obtained by investigating how the defocus changes with the change in the atmospheric pressure when the correction term K ₄ (ΔP / t) is added to Equation (2) as in the present embodiment. It is a graph.

In this investigation, a table value as shown in FIG. 11 was used as the second stage movement amount K ₄ . As shown in FIG. 11, the value of K ₄ was set to 0 when the atmospheric pressure fluctuation amount ΔP / t was between −2 and +2. This is because, as shown in FIG. 9, in this range is because the moving amount K ₄ is the even defocus correction by zero to some extent follows the change in atmospheric pressure. Also, to that of K ₄ at a constant value in the range of atmospheric pressure variation [Delta] P / t of 5 or more ranges and -6, the atmospheric pressure variation [Delta] P / t fall within these ranges are rare, they This is because it is sufficient to use the value of K ₄ when the value of the atmospheric pressure fluctuation amount ΔP / t is 5 and −6.

  As shown in FIG. 10, when the atmospheric pressure fluctuation amount ΔP / t is 4 hPa / hour, a defocus of 0.15 μm has occurred. In this embodiment, the atmospheric pressure fluctuation amount ΔP / t is Even in the case of 3 to 4 hPa / hour, the defocus can be suppressed to within ± 0.05 μm. Thereby, in the present embodiment, it is possible to improve the accuracy of defocus correction as compared with the case where only the stage adjustment table 41 (see FIG. 4) considering only the atmospheric pressure P is used. Even a stable focus margin can be obtained.

In the investigation result of FIG. 10, the value of the table shown in FIG. 11 is used as the second stage movement amount K _4. Of course, the movement amount K ₄ in the second stage adjustment table 42 described with reference to FIG. May be used.

In FIG. 10, only defocus correction is shown, but by adding the correction term K ₂ (ΔP / t) to Equation (1), the same tendency as in FIG. 10 can be obtained for magnification correction. In that case, as the second pressure regulating amount K _2, may be used the values of the table shown in FIG 12. In the example of FIG. 12, for the same reason as the second stage movement amount K ₄ shown in FIG. 11, the value of K ₂ is set to 0 when the atmospheric pressure fluctuation amount ΔP / t is between −2 and +2, and K ₂ is set to a constant value in a range where the atmospheric pressure fluctuation amount ΔP / t is 5 or more and −6 or less.

By using the correction term K ₂ (ΔP / t) corresponding to the atmospheric pressure fluctuation amount ΔP / t, it is compared with the case where only the first pressure adjustment table 31 (see FIG. 2) considering only the atmospheric pressure P is used. Thus, in this embodiment, the followability of magnification correction when the atmospheric pressure fluctuation amount ΔP / t is large can be improved, and a stable exposure margin can be obtained even with a large change in atmospheric pressure.

  There is no particular limitation on the correction timing of the exposure apparatus described above, that is, the timing at which the flowchart of FIG. 6 is executed. The timing may be the same as the sampling cycle for capturing the output value of the barometer 22 or may be finer than that. In the exposure apparatus according to the present embodiment, the timing can be arbitrarily set.

  In the above description, the correction method for one exposure apparatus has been described. However, when there are a plurality of exposure apparatuses in a semiconductor factory or the like, the correction is performed by the above method for each exposure apparatus.

  In this case, the first pressure adjustment table 31 and the second pressure adjustment table 32 do not have to be common to each exposure apparatus, and are preferably provided individually in each exposure apparatus based on the wrinkles of each apparatus.

  For the same reason, it is preferable to provide the first stage adjustment table 41 and the second stage adjustment table 42 individually for each exposure apparatus.

(3) Method for Manufacturing Electronic Device Next, a method for manufacturing an electronic device using the above exposure apparatus will be described.

  13 to 16 are cross-sectional views of the electronic device according to the present embodiment during manufacture. In this embodiment, a MOS transistor is formed as the electronic device.

  First, steps required until a sectional structure shown in FIG.

  First, a trench for element isolation is formed in an n-type or p-type silicon (semiconductor) substrate 50, and a silicon oxide film is formed as an element isolation insulating film 51 in the trench. Such an element isolation structure is called STI (Shallow Trench Isolation). Alternatively, an element isolation structure may be obtained by a LOCOS (Local Oxidation of Silicon) method.

  Next, a p-type impurity such as boron is introduced into the active region of the silicon substrate 50 to form a p-well 53, and then the surface of the active region is thermally oxidized to form a thermal oxide film as the gate insulating film 52 with about 6 Form a thickness of ˜7 nm.

  Subsequently, as shown in FIG. 13B, an amorphous silicon film 53a having a thickness of about 50 nm and a tungsten silicide film 53b having a thickness of about 150 nm are sequentially formed on the gate insulating film 52. A conductive film 53 is formed. Note that a polycrystalline silicon film may be formed instead of the amorphous silicon film 53a.

  Thereafter, a positive photoresist 54 is applied on the conductive film 53 by spin coating, and the photoresist 54 is cured (cured) by heat treatment.

  Next, steps required until a sectional structure shown in FIG.

  First, the flow shown in FIG. 6 is performed by the exposure apparatus described in FIG. In this example, it is assumed that the atmospheric pressure fluctuation amount does not exceed the upper limit value in step S2 of FIG. 6, and the lens system magnification correction and defocus correction are performed in step S3. The correction method is as described in detail with reference to FIGS.

  After the correction is completed as described above, the photoresist 54 is exposed using an exposure apparatus as shown in FIG. A photosensitive portion 54 a is formed in the photoresist 54 exposed by this exposure.

  Next, as shown in FIG. 14B, the above-described photoresist is developed, and only a portion corresponding to the photosensitive portion 54a is left on the conductive film 53 as a resist pattern 54b.

  Next, as shown in FIG. 15A, the conductive film 54 is etched using the resist pattern 54b as a mask, and the conductive film 54 that remains without being etched is used as a gate electrode (device pattern) 53c. In this etching, the portion of the gate insulating film 52 not covered with the gate electrode 53c is also etched away.

  Thereafter, the resist pattern 54b is removed.

  Next, as shown in FIG. 15B, phosphorus is introduced as an n-type impurity into the silicon substrate 50 beside the gate electrode 53c by ion implantation using the gate electrode 53c as a mask to form source / drain extensions 55. .

  Subsequently, as shown in FIG. 16, an insulating film is formed on the entire upper surface of the silicon substrate 50, and the insulating film is etched back to leave an insulating spacer 57 beside the gate electrode 53c. As the insulating film, a silicon oxide film is formed by, for example, a CVD (Chemical Vapor Deposition) method.

  Then, while using the insulating spacer 57 and the gate electrode 53c as a mask, n-type impurities such as arsenic are ion-implanted again into the silicon substrate 50, whereby the source / drain regions 56 are formed in the silicon substrate 50 lateral to the gate electrode 53c. Form.

  Thereafter, the process proceeds to a step of forming a cobalt silicide layer on the source / drain region 56 and forming an interlayer insulating film or the like on the cobalt silicide layer, but details thereof are omitted.

  Through the steps so far, a MOS transistor including the gate insulating film 52, the gate electrode 53c, the source / drain region 56, and the like is formed in the active region of the silicon substrate 50.

According to the manufacturing method of the electronic apparatus described above, the magnification correction and the defocus correction of the exposure apparatus were performed according to the flow of FIG. 6 before performing the exposure in the process of FIG. The correction uses correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) corresponding to the atmospheric pressure fluctuation amount ΔP / t as in the above-described equations (1) and (2). The correction results follow changes in atmospheric pressure. Therefore, even when the atmospheric pressure fluctuation amount ΔP / t is large as in the case where the typhoon passes at high speed, the gate electrode formed by etching using the resist pattern 54b as a mask because the magnification fluctuation and defocus are within the exposure margin. The line width of 53c can be within the standard value.

In particular, when a fine design rule, for example, a design rule with a gate length of 0.13 μm or 0.18 μm is used, the exposure margin becomes very narrow, and the correction term K ₂ according to the atmospheric pressure fluctuation amount ΔP / t. Without (ΔP / t) and K ₄ (ΔP / t), the correction does not follow the atmospheric pressure fluctuation, and the line width of the resist pattern 54b tends to deviate from the standard value. In contrast, in the present embodiment using the correction terms K ₂ (ΔP / t) and K ₄ (ΔP / t) as described above, even with such a fine design rule, the correction accuracy is increased. The line width of the resist pattern 54b can be kept within the standard value.

  In this example, a MOS transistor is formed as an electronic device, but the present invention is not limited to this. For example, the present invention can also be applied to an exposure process in a TFT (Thin Film Transistor) manufacturing process of a liquid crystal panel.

Claims (18)

A barometer to measure atmospheric pressure;
A lens barrel sealed inside;
A lens system housed in the lens barrel;
A pressure adjusting unit for adjusting the pressure in the lens barrel;
A stage on which a substrate can be placed and raised and lowered;
An output value of the barometer is taken at a predetermined sampling period to calculate an atmospheric pressure fluctuation amount per unit time, and the pressure adjusting unit is based on the calculated atmospheric pressure fluctuation quantity and the taken atmospheric pressure. To correct the magnification of the lens system accompanying atmospheric pressure fluctuations, or to raise and lower the stage to correct defocusing of the lens system accompanying atmospheric pressure fluctuations;
An exposure apparatus comprising: A first pressure adjustment table composed of a pair of a first pressure adjustment amount and an atmospheric pressure, and a second pressure composed of a pair of a second pressure adjustment amount and an atmospheric pressure fluctuation amount per unit time. A storage unit storing the adjustment table;
The control unit acquires a first pressure adjustment amount corresponding to the taken-in atmospheric pressure from the first pressure adjustment table, and the second pressure adjustment corresponding to the calculated atmospheric pressure fluctuation amount. The pressure adjustment is acquired from the second pressure adjustment table, and the pressure adjustment is performed so as to adjust the pressure in the lens barrel by the sum of the acquired first pressure adjustment amount and the second pressure adjustment amount. The exposure apparatus according to claim 1, wherein the exposure unit is instructed to correct the magnification. The first pressure adjustment amount is a pressure adjustment amount in the lens barrel necessary to make the magnification of the lens system equal to the magnification at the reference atmospheric pressure under the condition that the atmospheric pressure fluctuation amount is zero. Yes,
When the atmospheric pressure fluctuation amount is not zero, the second pressure adjustment amount is necessary in the lens barrel together with the first pressure adjustment amount to obtain the same magnification as that when the atmospheric pressure fluctuation amount is zero. The exposure apparatus according to claim 2, wherein the pressure adjustment amount of the exposure apparatus is the same. A first stage adjustment table composed of a pair of first stage movement amount and atmospheric pressure, and a second stage composed of a pair of second stage movement amount and atmospheric pressure fluctuation amount per unit time A storage unit storing the adjustment table;
The control unit acquires a first stage movement amount corresponding to the taken-in atmospheric pressure from the first stage adjustment table, and the second stage movement corresponding to the calculated atmospheric pressure fluctuation amount. An amount is acquired from the second stage adjustment table, and the stage is moved up and down by the sum of the acquired first stage movement amount and the second stage movement amount to correct the defocus. The exposure apparatus according to claim 1, wherein: The first stage moving amount is an amount by which the stage is moved up and down necessary to make the lens system out of focus under the condition that the atmospheric pressure fluctuation amount is zero.
The second stage movement amount is an amount by which the stage is moved up and down together with the first stage movement amount in order to make the defocusing zero when the atmospheric pressure fluctuation amount is not zero. The exposure apparatus according to claim 4.   2. The control unit according to claim 1, wherein when the calculated amount of fluctuation in atmospheric pressure exceeds a predetermined upper limit value, the control unit stops receiving the substrate to be exposed next. Exposure device.   The exposure apparatus according to claim 1, wherein the control unit issues an alarm when the calculated amount of fluctuation in atmospheric pressure exceeds a predetermined upper limit value.   The exposure apparatus according to claim 1, wherein the magnification correction and the defocus correction timing can be arbitrarily set. Taking the output value of the barometer at a predetermined sampling period and calculating the amount of atmospheric pressure fluctuation per unit time;
A correction step for correcting changes in the optical characteristics of the lens system due to atmospheric pressure fluctuations,
The correction step includes
Based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure, the pressure in the lens barrel sealed inside is adjusted to correct the magnification of the lens system housed in the lens barrel. Step to do,
Alternatively, the method includes any one of the steps of correcting the defocus of the lens system by raising and lowering the stage on which the substrate is placed based on the calculated atmospheric pressure fluctuation amount and the captured atmospheric pressure. And a correction method for an exposure apparatus. The step of correcting the magnification includes
With reference to a first pressure adjustment table configured by a pair of the first pressure adjustment amount and the atmospheric pressure, the first pressure adjustment amount corresponding to the taken-in atmospheric pressure is obtained from the first pressure adjustment table. A step to obtain,
The second pressure adjustment amount corresponding to the calculated atmospheric pressure fluctuation amount with reference to a second pressure adjustment table composed of a pair of the second pressure adjustment amount and the atmospheric pressure fluctuation amount per unit time. Obtaining from the second pressure adjustment table;
The exposure apparatus correction method according to claim 9, further comprising a step of adjusting the pressure in the lens barrel by an amount corresponding to a sum of the acquired first pressure adjustment amount and second pressure adjustment amount. . The first pressure adjustment amount is a pressure adjustment amount in the lens barrel necessary to make the magnification of the lens system equal to the magnification at the reference atmospheric pressure under the condition that the atmospheric pressure fluctuation amount is zero. Yes,
When the atmospheric pressure fluctuation amount is not zero, the second pressure adjustment amount is necessary in the lens barrel together with the first pressure adjustment amount to obtain the same magnification as that when the atmospheric pressure fluctuation amount is zero. The exposure apparatus correction method according to claim 10, wherein the pressure adjustment amount of the exposure apparatus is 10 μm.   The exposure apparatus correction method according to claim 10, wherein a plurality of the exposure apparatuses are provided, and the first pressure adjustment table and the second pressure adjustment table are individually provided in the plurality of exposure apparatuses. The step of correcting the defocus is:
Referring to a first stage adjustment table composed of a pair of first stage movement amount and atmospheric pressure, the first stage movement amount corresponding to the taken-in atmospheric pressure is obtained from the first stage adjustment table. A step to obtain,
The second stage movement amount corresponding to the calculated atmospheric pressure fluctuation amount with reference to a second stage adjustment table configured with a pair of the second stage movement amount and the atmospheric pressure fluctuation amount per unit time. Obtaining from the second stage adjustment table;
The exposure apparatus correction method according to claim 9, further comprising a step of moving the stage up and down by a sum of the acquired first stage movement amount and second stage movement amount. The first stage moving amount is an amount by which the stage is moved up and down necessary to make the lens system out of focus under the condition that the atmospheric pressure fluctuation amount is zero.
The amount of movement of the second stage is
14. The exposure apparatus according to claim 13, wherein when the atmospheric pressure fluctuation amount is not zero, the amount of movement of the stage is necessary together with the first stage movement amount in order to make the focus shift zero. Correction method.   The exposure apparatus correction method according to claim 13, wherein a plurality of the exposure apparatuses are provided, and the first stage adjustment table and the second stage adjustment table are individually provided in the plurality of exposure apparatuses. Forming a film on the substrate;
Applying a photoresist on the film;
Correcting the change in optical characteristics of the exposure apparatus due to atmospheric pressure fluctuations;
After the correction, exposing the photoresist using the exposure apparatus;
After the exposure, developing the photoresist into a resist pattern;
Etching the film using the resist pattern as a mask, and making the film left unetched a device pattern;
Removing the resist pattern,
The step of correcting the change in the optical characteristics of the exposure apparatus includes:
Take the output value of the barometer at a predetermined sampling period and calculate the atmospheric pressure fluctuation amount per unit time,
Based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure, the pressure in the lens barrel sealed inside is adjusted to correct the magnification of the lens system housed in the lens barrel. Alternatively, based on the calculated atmospheric pressure fluctuation amount and the captured atmospheric pressure, the stage on which the substrate is placed is moved up and down to correct the defocus of the lens system. A method for manufacturing an electronic device. The magnification correction is
Referring to a first pressure adjustment table configured by a pair of a first pressure adjustment amount and an atmospheric pressure, a first pressure adjustment amount corresponding to the taken-in atmospheric pressure is determined as the first pressure adjustment table. Get from
The second pressure adjustment corresponding to the calculated atmospheric pressure fluctuation amount with reference to a second pressure adjustment table composed of a pair of the second pressure adjustment amount and the atmospheric pressure fluctuation amount per unit time. An amount is obtained from the second pressure regulation table;
The method of manufacturing an electronic device according to claim 16, wherein the method is performed by adjusting the pressure in the lens barrel by an amount corresponding to the sum of the acquired first pressure adjustment amount and the second pressure adjustment amount. . The defocus correction is
Referring to a first stage adjustment table configured by a pair of a first stage movement amount and an atmospheric pressure, the first stage movement amount corresponding to the taken-in atmospheric pressure is determined as the first stage adjustment table. Get from
The second stage movement corresponding to the calculated atmospheric pressure fluctuation amount with reference to a second stage adjustment table composed of a pair of the second stage movement amount and the atmospheric pressure fluctuation amount per unit time. An amount is obtained from the second stage adjustment table;
The method of manufacturing an electronic apparatus according to claim 16, wherein the stage is moved up and down by the sum of the acquired first stage movement amount and second stage movement amount.

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