WO2007096949A1

WO2007096949A1 - Photo lithography system, photo lithography method and method for fabricating electronic device

Info

Publication number: WO2007096949A1
Application number: PCT/JP2006/303064
Authority: WO
Inventors: Hitoshi Kikuchi
Original assignee: Fujitsu Limited
Priority date: 2006-02-21
Filing date: 2006-02-21
Publication date: 2007-08-30
Also published as: JPWO2007096949A1

Abstract

[PROBLEMS] To provide a photo lithography system exhibiting good correction follow-up performance for variation in atmospheric pressure, and to provide its correction method and a method for fabricating an electronic device. [MEANS FOR SOLVING PROBLEMS] The optical lithography system comprises a barometer (22) for measuring atmospheric pressure (P), a body tube (14) having enclosed interior, a lens system (15) contained in the body tube (14), a pressure regulating section (16) for regulating the pressure in the body tube (14), a stage (18) which can elevate/lower with a substrate (100) mounted, and a control section (21) for taking in the atmospheric pressure (P) measured by the barometer (22) at a predetermined sampling period, calculating the variation in atmospheric pressure per unit time (ΔP/t), controlling the pressure regulating section (16) based on the variation in atmospheric pressure (ΔP/t) thus calculated and the atmospheric pressure (P) thus taken in to correct the magnification of the lens system (15) incident to variation in atmospheric pressure, or to correct defocusing of the lens system (15) incident to variation in atmospheric pressure by elevating/lowering the stage (18).

Description

Specification

EXPOSURE APPARATUS, EXPOSURE METHOD, AND ELECTRONIC DEVICE MANUFACTURING METHOD

Technical field

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

Background art

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

[0003] In Patent Documents 1 to 3, such correction is performed based on the value of atmospheric pressure.

[0004] Also, in Patent Document 4, the atmospheric pressure measured by a barometer is also used to estimate the atmospheric pressure in the lens barrel and perform the above correction using the estimated value.

However, if only the atmospheric pressure value is used as in Patent Documents 1 to 3, there is a disadvantage that the follow-up performance of the correction is deteriorated when the atmospheric pressure fluctuation is large, such as when a typhoon passes. . Patent Document 1: Japanese Utility Model Publication No. 63-178320

Patent Document 2: Japanese Utility Model Publication 8-21531

Patent Document 3: Japanese Patent Laid-Open No. 2003-59807

Patent Document 4: Japanese Patent No. 3387861

Disclosure of the invention

[0006] 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 follow-up of correction with respect to fluctuations in atmospheric pressure.

[0007] According to an aspect of the present invention, a barometer for measuring atmospheric pressure, a lens barrel sealed inside, a lens system housed in the lens barrel, and a pressure in the lens barrel are adjusted. A pressure adjustment unit that can be moved up and down, and a stage on which the substrate can be moved up and down, and an output value of the barometer The atmospheric pressure fluctuation amount per unit time is calculated by taking in the cyclic period, and the pressure adjustment unit is controlled based on the calculated atmospheric pressure fluctuation amount and the taken atmospheric pressure to accompany the atmospheric pressure fluctuation. There is provided an exposure apparatus including a control unit that corrects the magnification of the lens system or moves the stage up and down to correct a defocus of the lens system due to atmospheric pressure fluctuation.

[0008] According to the present invention, since the magnification correction and 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 atmospheric pressure fluctuation is large, it is possible to sufficiently reduce the magnification fluctuation and the defocus.

[0009] Further, according to another aspect of the present invention, a step of taking an output value of a barometer at a predetermined sampling period and calculating an atmospheric pressure fluctuation amount per unit time, and a lens system associated with the atmospheric pressure fluctuation, A correction step for correcting a change in optical characteristics, and the correction step calculates the pressure in the lens barrel with the inside sealed based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure. Adjusting to correct the magnification of the lens system contained in the lens barrel, or based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure! There is provided a correction method for an exposure apparatus including one of the steps of correcting a defocus of the lens system by moving a stage placed up and down.

[0010] According to still another aspect of the present invention, a step of forming a film on the substrate, a step of applying a photoresist on the film, and an optical characteristic of the exposure apparatus accompanying atmospheric pressure fluctuations A step of correcting the change, a step of exposing the photoresist using the exposure apparatus after the correction, a step of developing the photoresist to form a resist pattern after the exposure, and the resist Etching the film using a pattern as a mask, and using the film left unetched as a device pattern and removing the resist pattern, and correcting the change in the optical characteristics of the exposure apparatus The step of calculating the atmospheric pressure fluctuation amount per unit time by taking in the output value of the barometer at a predetermined sampling period, and calculating the calculated atmospheric pressure fluctuation amount and the taken-in air Based on the above, the pressure in the lens barrel with the inside sealed is adjusted to correct the magnification of the lens system housed in the lens barrel, or the calculated atmospheric pressure fluctuation amount and the capture Based on the atmospheric pressure, the stage on which the substrate is placed is moved up and down to correct the defocus of the lens system. The manufacturing method of the electronic device performed by this is provided.

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. For this reason, the correction result follows the atmospheric pressure fluctuation well, and even when the atmospheric pressure fluctuation is large, the line width of the device pattern can be easily kept within the standard value.

Brief Description of Drawings

FIG. 1 is a block diagram of an exposure apparatus used in an 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 for an exposure apparatus according to an embodiment of the present invention.

FIG. 7 is a flowchart showing details of a step of correcting the magnification of the lens system in the embodiment of the present invention.

FIG. 8 is a flowchart showing details of a step for correcting the defocus of the lens system in the embodiment of the present invention.

[FIG. 9] FIG. 9 shows that when the atmospheric pressure changes with time, the correction term K (Δ Ρ / t) is not used.

Four

It is the graph obtained by investigating how a point shift changes with time.

[FIG. 10] FIG. 10 shows the case where the correction term K (ΔΡ / t) is used as in the embodiment of the present invention.

Four

This is a dull obtained by investigating how defocusing changes with changes in atmospheric pressure.

[FIG. 11] FIG. 11 is a diagram showing the value of the correction term K (ΔΡ / t) used in the investigation of FIG.

Four

[FIG. 12] FIG. 12 is a diagram showing the value of the correction term K (ΔΡ / t) that can be used in the embodiment of the present invention. is there.

13 (a) and 13 (b) are cross-sectional views (part 1) of the electronic device according to the embodiment of the present invention in the middle of manufacture.

14 (a) and 14 (b) are cross-sectional views (part 2) of the electronic device according to the embodiment of the present invention in the middle of manufacture.

15 (a) and 15 (b) are cross-sectional views (part 3) of the electronic device according to the embodiment of the present invention in the middle of manufacture.

FIG. 16 is a cross-sectional view (part 4) of the electronic device according to the embodiment of the present invention in the middle of manufacture.

BEST MODE FOR CARRYING OUT THE INVENTION

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.

The 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.

[0017] The lens barrel 14 is sealed inside, and a lens system 15 including a plurality of lenses 15a is accommodated in the lens barrel 14. Further, 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 has an elevating mechanism 19 that elevates the substrate 100 in the direction shown in the drawing toward the lens barrel 14, and further includes a distance measuring unit 20 for measuring the elevating distance.

In addition, the control unit 21 includes a pressure controller 23, a storage unit 25, and a focus controller 24.

[0020] The pressure controller 23 captures the atmospheric pressure value (P) output from the barometer 22 at a predetermined sampling period, for example, a period of 30 minutes, and the atmospheric pressure fluctuation amount per unit time (ΔΡ / t) It has a function to calculate. And a pressure adjusting tape described later stored in the storage unit 25 , The atmospheric pressure value (P), and the atmospheric pressure fluctuation amount (ΔΡ / t), the pressure controller 23 instructs the pressure adjustment unit 16 on the pressure adjustment amount.

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. As a result, the pressure in the lens barrel 14 is controlled by a closed loop system.

[0022] Similarly to the pressure controller 23, the focus controller 24 also sets the atmospheric pressure value (P).

Atmospheric pressure fluctuation per unit time (taken at a predetermined sampling period of about 30 minutes (

It has a function of calculating ΔΡ / t). The focus controller 24 then moves the moving mechanism 19 up and down based on a stage adjustment table (described later) stored in the storage unit 25, the atmospheric pressure value (P), and the atmospheric pressure fluctuation amount (ΔΡ / t). Instruct.

It should be noted that the above lifting 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, the 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. Become.

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.

[0026] 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. Therefore, it can be corrected by adjusting the pressure in the lens barrel 14.

On the other hand, the defocus due to the variation in the 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.

FIG. 2 to FIG. 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, the first pressure adjustment table 31 is composed of a pair of the first pressure adjustment amount K and the atmospheric pressure P (hPa).

1

Made.

[0031] The first pressure adjustment amount K is a value under the condition that the atmospheric pressure fluctuation amount ΔΡ / t is zero. This is the amount of pressure adjustment in the lens barrel 14 necessary to make the magnification of the glass system 15 equal to the magnification at the reference atmospheric pressure (for example, lOOOhPa). For example, in the example shown in the figure, when the atmospheric pressure fluctuation Δ Ρ / t is zero and the atmospheric pressure P is lOlOhPa, the pressure adjustment amount in the lens barrel 14 is set to +1 so that the reference atmospheric pressure (lOOOhPa) is Can be the same magnification.

[0032] The pressure adjustment amount is measured in a control unit, and the pressure unit (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 the second pressure adjustment amount K and the atmospheric pressure fluctuation amount Δ Ρ / t per unit time.

2

It consists of a pair with (hPa / hour).

[0034] The second pressure adjustment amount K is the atmospheric pressure fluctuation amount when the atmospheric pressure fluctuation amount ΔP / t is not zero.

2

In order to obtain the same magnification as when ΔΡ / t is zero, the lens barrel required with the first pressure adjustment K 1

1

4 is the pressure adjustment amount.

FIG. 4 is a diagram schematically showing the first stage adjustment table 41. As shown in this figure, the first stage adjustment table 41 includes the first stage movement amount K and the atmospheric pressure P.

Three

It consists of a pair with (hPa).

[0036] The first stage moving amount K is the lens under the condition that the atmospheric pressure fluctuation amount ΔΡ / t is zero.

Three

This is the amount of elevation of the stage 18 necessary to make the system 15 defocused to zero. For example, in the example shown in the figure, when the atmospheric pressure fluctuation amount Δ ゼロ / 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.

[0037] 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 the second stage movement amount K and the atmospheric pressure per unit time.

Four

It consists of a pair with the fluctuation amount Δ P / t (hPa / hour).

[0039] The second stage movement amount K is the amount of defocus when the atmospheric pressure fluctuation amount ΔP / t is not zero.

Four

Along with the first stage travel K to make it zero

Three

In each table shown in FIGS. 2 to 5, the operator can change the atmospheric pressure P and the atmospheric pressure fluctuation amount Δ Δ / t. By monitoring the defocus and magnification fluctuations in the exposure apparatus shown in Fig. 1 while monitoring the above, each exposure apparatus is manufactured individually.

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

[0042] (2) Exposure apparatus correction method

FIG. 6 is a flowchart showing a correction method of the exposure apparatus.

[0043] In the first step S1, the control unit 21 captures the atmospheric pressure value P output from the barometer 22 at a predetermined sampling period, for example, a period of 30 minutes, and the atmospheric pressure fluctuation amount per unit time ΔΡ / t is calculated. The pressure controller 23 or the focus controller 24 calculates the atmospheric pressure fluctuation amount Δ 又は / 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 a factory where the exposure apparatus is installed. This is because it is unknown how the magnification fluctuation and defocus in the exposure apparatus behave at an atmospheric pressure fluctuation Δ P / t exceeding the maximum value.

[0045] 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, Next, the acceptance of the substrate 10 to be exposed is stopped. 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, if it is determined that the atmospheric pressure fluctuation amount ΔP / t does not exceed the upper limit value (NO), the process proceeds to the correction step S3.

[0048] The correction step S3 includes a step S4 for correcting the magnification of the lens system 15 and a step S5 for correcting a defocus of the lens system 15.

[0049] Among them, in step S4, by adjusting the pressure in the lens barrel 14, the same magnification as when the atmospheric pressure P is the standard atmospheric pressure (for example, lOOOhPa) and the atmospheric pressure fluctuation amount ΔP / t is zero is obtained. Get. [0050] On the other hand, in step S5, the defocus is set to zero by adjusting the lift of the stage 18.

FIG. 7 is a flowchart showing details of step S 4 for correcting the magnification of the lens system 15.

[0052] In the first step S 10 of FIG. 7, the pressure controller 23 refers to the first pressure adjustment table 31 (FIG. 2), and the first pressure adjustment amount K ( P)

1

Next, the process proceeds to step S 11, where the pressure controller 23 moves the second pressure adjustment table 32.

Referring to (Fig. 3), a second pressure adjustment amount Κ (Δ ΡΛ) corresponding to the atmospheric pressure fluctuation amount ΔP / t obtained in step S1 is obtained.

2

[0054] Subsequently, the process proceeds to step S12, and the pressure LP to be applied in the lens barrel 14 is expressed by the following equation (1).

2

Ask.

[0055] LP = Ρ + Ρ (Ρ) + Κ (Δ ΡΑ) · · · · (1)

2 1 2

In equation (1), the increase from the atmospheric pressure 、, that is, Κ (Ρ) + Κ (Δ Ρ / t) is applied to the lens barrel 14.

1 2

This is the pressure adjustment amount to be obtained.

[0056] The pressure controller 23 adjusts the pressure in the lens barrel 14 by this pressure adjustment amount Κ (Ρ) + Κ (Δ Ρ / t).

1 2

The pressure adjustment unit 16 is controlled so as to be adjusted, and thereby the magnification correction according to the atmospheric pressure fluctuation is performed.

On the other hand, FIG. 8 is a flowchart showing details of step S 5 for correcting the defocus of the lens system 15.

[0058] In the first step S15 of FIG. 8, the focus controller 24 refers to the first stage adjustment table 41 (FIG. 4), and the first stage movement amount Κ (Ρ )

3 Get.

[0059] Next, the process proceeds to step S16, and the focus controller 24 refers to the second stage adjustment table 42 (Fig. 5) and corresponds to the atmospheric pressure fluctuation amount ΔP / t obtained in step S1. Obtain the second stage travel Κ (Δ P / t).

Four

[0060] Subsequently, the process proceeds to step S17, and the lift FO of the stage 18 necessary to make the defocus zero is obtained by the following equation (2). [0061] FO = Κ (Ρ) + Κ (Δ ΡΑ) · · · · (2)

2 3 4

The focus controller 24 is a lifting mechanism 1 so that the stage 18 moves up and down by this FO 1

2

9 is controlled so that the defocus due to 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.

[0063] Incidentally, the above-described equations (1) and (2) are expressed by the correction term K (Δ

2

P / t) and Κ (Δ ΡΛ).

Four

[0064] On the other hand, as in Patent Documents 1 to 3, these correction terms Ρ (Δ ΡΛ), Κ are obtained from Equations (1) and (2).

twenty four

It is conceivable to correct by reducing (Δ P / t).

[0065] Fig. 9 shows that when the atmospheric pressure changes with time, the correction term Κ (Δ

Four

It is a graph obtained by investigating how the defocus changes with time when P / t) is lowered.

As shown in FIG. 9, if the change in atmospheric pressure is slow (about lhPa / hour), sufficient correction can be performed even if the correction term K (ΔΡ / t) is reduced. For example, the atmospheric pressure fluctuation amount Δ P / t is

Four

If it 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 will be 0.05 m or less. This value is not a problem because it is within the range of defocus that can be controlled by the exposure system.

[0067] However, the actual changes in atmospheric pressure vary, and the atmospheric pressure fluctuation Δ P / t increases when the typhoon passes or when the winter-type pressure distribution in the west high, east, low is collapsed rapidly. If Κ (Δ P / t) is reduced, the temporal followability of the correction will be poor. According to Figure 9,

Four

When the positive term Κ (Δ P / t) is reduced, the correction follows that the atmospheric pressure fluctuation amount Δ Ρ / t is 2 hPa / ho.

Four

Up to about ur, and beyond that, the followability deteriorates as the atmospheric pressure fluctuation amount ΔP / t increases. In particular, when a high-speed typhoon passes, the atmospheric pressure fluctuation amount Δt / t force may reach 5hPa / hour, and in this case, the error of defocus correction becomes large.

[0068] As is apparent from FIG. 9, when the atmospheric pressure fluctuation amount Δ と / t is about 3 hPa / hour, the defocus is about 0.1 m. If a layer with a severe focus margin is exposed in this state, patterning defects such as shape defects and line width defects occur in that layer. Furthermore, it can be seen that when the atmospheric pressure fluctuation amount Δ Ρ / t is 4 hPa / hour, the defocus is 0.1 to 0.2 m. [0069] Regarding the fluctuation of the magnification, if the atmospheric pressure fluctuation Δ P / t is within 2 hPa / hour, the magnification fluctuation is 1 ppm even if the correction term K (Δ P / t) is dropped from Equation (1). It is this application that it can be suppressed to the extent

2

Inventor's experience is known. This value is not particularly problematic when aligning the substrate 100 and the exposure apparatus.

[0070] However, the atmospheric pressure fluctuation amount Δ P / t is reduced to about 3 hPa / hour with the correction term K (Δ P / t) reduced.

2

Then, the magnification fluctuation is about 2 ppm, and the alignment margin between the substrate 100 and the exposure apparatus is severe. . In addition, if the atmospheric pressure fluctuation ΔΡ / t is 4 hPa / hour or more, the magnification fluctuation is 2 to 3 ppm, which may cause a considerable defect.

[0071] As described above, the correction terms Κ (Δ ΡΛ), Κ (in accordance with the atmospheric pressure fluctuation amount Δ P / t from Equations (1) and (2).

twenty four

If Δ P / t) is reduced, the defocus correction and magnification correction cannot follow the atmospheric pressure fluctuation.

In contrast, in the present embodiment, correction terms K (Δ P / t) and K (Δ P / t) are added to equations (1) and (2).

twenty four

Therefore, it is possible to perform correction following the atmospheric pressure fluctuation.

[0073] FIG. 10 shows a large case when the correction term Δ (ΔP / t) is added to the equation (2) as in this embodiment.

Four

It is a graph obtained by investigating how defocusing changes with changes in atmospheric pressure.

[0074] In this investigation, the tape as shown in FIG. 11 is used as the second stage movement amount K.

Four

Value was used. As shown in Fig. 11, when the atmospheric pressure fluctuation Δ P / t is between -2 and +2, the value of is zero. This is because, as shown in Fig. 9, the movement amount K is zero in this range.

4 4 is also because defocus correction follows the atmospheric pressure fluctuation to some extent. Also, atmospheric pressure fluctuation

The reason why K is a constant value in the range where Δ P / t is 5 or more and 6 or less is large in these ranges.

Four

This is because the atmospheric pressure fluctuation Δ P / t rarely enters, and in these ranges it is sufficient to use the K value when the atmospheric pressure fluctuation Δ P / t is 5 or 6.

Four

[0075] As shown in Fig. 10, this embodiment has a large defocus of 0.15 / zm when the atmospheric pressure fluctuation amount ΔΡ / t is 4hPa / hour. The defocus can be suppressed to within ± 0.05 m even when the atmospheric pressure fluctuation Δ Ρ / t is 3-4 hPa / hour. As a result, in this embodiment, the accuracy of defocus correction can be improved compared to the case where only the stage adjustment table 41 (see FIG. 4) that considers only the atmospheric pressure P is used, and a large atmospheric pressure change is achieved. In contrast, a stable focus margin can be obtained.

[0076] In the investigation result of FIG. 10, the table shown in FIG.

Four

Although the bull value is used, of course, the movement amount K in the second stage adjustment table 42 described in FIG. 5 may be used.

Four

[0077] In FIG. 10, the correction term K (Δ (/ t) is added to the force equation (1) shown only for the defocus correction.

By adding 2, the same tendency as in Figure 10 can be obtained for magnification correction. In this case, the value in the table shown in FIG. 12 may be used as the second pressure adjustment amount K. Figure 12 example

2

Then, for the same reason as the second stage movement amount K shown in FIG. 11, the atmospheric pressure fluctuation amount Δ Ρ / t

Four

The value of K between 0 and +2 is 0, and the atmospheric pressure fluctuation Δ Ρ / t is in the range of 5 or more.

2

K is kept constant within the range of 6 or less.

2

[0078] Only the atmospheric pressure P is considered by using the correction term K (Δ P / t) corresponding to the atmospheric pressure fluctuation amount Δ P / t.

2

Compared to the case where only the first pressure adjustment table 31 (see Fig. 2) is used, in this embodiment, the atmospheric pressure fluctuation amount Δ P / t is large, and the follow-up performance of magnification correction in this case is improved. In addition, a stable exposure margin can be obtained even with a large change in atmospheric pressure.

[0079] The timing of the above-described exposure apparatus correction, that is, the timing for executing the flowchart of FIG. 6 is not particularly limited. The timing may be the same as the sampling period at which the output value of the barometer 22 is captured, or may be more powerful than that. In the exposure apparatus according to the present embodiment, the timing can be arbitrarily set.

Further, in the above, the force described for the correction method for one exposure apparatus. When there are a plurality of exposure apparatuses in a semiconductor factory or the like, correction is performed for each exposure apparatus by the above method.

[0081] In that case, the first pressure adjustment table 31 and the second pressure adjustment table 32 are individually provided in each exposure apparatus based on the length of each apparatus that does not need to be common to each exposure apparatus. Is preferred.

[0082] For the same reason, it is preferable that the first stage adjustment table 41 and the second stage adjustment table 42 are also individually provided in each exposure apparatus.

[0083] (3) Manufacturing method of electronic device

Next, a method for manufacturing an electronic apparatus using the above exposure apparatus will be described. FIGS. 13 to 16 are cross-sectional views of the electronic device according to this embodiment in the middle of manufacture. In this embodiment, a MOS transistor is formed as the electronic device.

[0085] First, steps required until a sectional structure shown in FIG.

First, an element isolation trench is formed in an n-type or p-type silicon (semiconductor) substrate 50, and an oxide silicon film is formed as an element isolation insulating film 51 in the trench. Such an element isolation structure is S

It is called TI (Shallow Trench Isolation), but instead of LOCOS (Local Oxidation of

The isolation structure can be obtained by the silicon method.

Next, a p-type impurity such as boron is introduced into the active region of the silicon substrate 50 to form p-well.

After forming 53, the surface of the active region is subjected to thermal oxidation to form a thermal oxide film having a thickness of about 67 nm as the gate insulating film 52.

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 are sequentially formed on the gate insulating film 52. A conductive film 53 composed of these films is formed. Note that a polycrystalline silicon film may be formed instead of the amorphous silicon film 53a.

[0089] 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 in FIG. 6, and lens 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 photo register 54 is exposed using an exposure apparatus as shown in FIG. 14 (a). A photosensitive portion 54 a is formed in the photoresist 54 exposed by this exposure.

Next, as shown in FIG. 14B, the above 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. 15 (a), the conductive film 54 is etched using the resist pattern 54b as a mask, and the conductive film 54 remaining without being etched is turned into a gate electrode (device pattern) 53c. And 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. 15 (b), 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. Drain extension 55 is formed.

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.

[0098] Then, while using the insulating spacer 57 and the gate electrode 53c as a mask, the silicon substrate 5

By re-implanting _n- type impurities such as arsenic into 0, a source Z drain region 56 is formed in the silicon substrate 50 on the side of the gate electrode 53c.

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

[0100] Through the steps so far, the gate insulating film 52, the gate electrode are formed in the active region of the silicon substrate 50.

A MOS transistor constituted by 53c, the source Z drain region 56, and the like is formed.

According to the electronic device manufacturing method described above, the exposure apparatus magnification correction and defocus correction were performed in accordance with the flow of FIG. 6 before exposure was performed in the step of FIG. 14 (a). The correction is performed by the correction terms Κ (Δ ΡΛ), Κ (Δ (Δ) corresponding to the atmospheric pressure fluctuation amount ΔP / t as in the equations (1) and (2).

twenty four

P / t) is used, and the correction result follows the atmospheric pressure fluctuation. Therefore, even when the atmospheric pressure fluctuation amount ΔP / t is large, such as when a typhoon passes at high speed, the magnification fluctuation and defocusing are within the exposure margin, and the resist pattern 54b is used as a mask. It becomes possible to keep the line width of the gate electrode 53c within the standard value.

[0102] In particular, when using a fine design rule, for example, a design rule with a gate length of 0.13 m or 0.18 μm, the exposure margin becomes very narrow and the atmospheric pressure variation Δ P / If there are no correction terms Κ (Δ ΡΛ) and Κ (Δ P / t) according to t, the correction will not follow atmospheric pressure fluctuations. As a result, the line width of the resist pattern 54b easily deviates from the standard value. In contrast, in the present embodiment using the correction terms Κ (Δ ΡΛ) and Κ (Δ Ρ / t) as described above, such a fine design is used.

twenty four

Even if it is a rule, the accuracy of the correction can be increased and the line width of the resist pattern 54b can be kept within the standard value.

In this example, the power of forming a MOS transistor as an electronic device 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

The scope of the claims

[1] 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;

The output value of the barometer is captured at a predetermined sampling period to calculate the atmospheric pressure fluctuation amount per unit time, and the pressure adjustment is performed based on the calculated atmospheric pressure fluctuation amount and the captured atmospheric pressure. A control unit for controlling the lens unit to correct the magnification of the lens system due to atmospheric pressure fluctuations, or to raise and lower the stage to correct the lens system defocusing due to atmospheric pressure fluctuations;

An exposure apparatus comprising:

[2] A first pressure adjustment table composed of a pair of a first pressure adjustment amount and an atmospheric pressure, and a first pressure adjustment table composed of a pair of a second pressure adjustment amount and an atmospheric pressure fluctuation amount per unit time. 2 has a storage unit storing the pressure adjustment table,

The control unit acquires the first pressure adjustment table force as the first pressure adjustment amount corresponding to the taken-in atmospheric pressure, and the second pressure corresponding to the calculated atmospheric pressure fluctuation amount. An adjustment amount is acquired from the second pressure adjustment table, and the pressure in the lens barrel is adjusted by the sum of the acquired first pressure adjustment amount and second pressure adjustment amount. The exposure apparatus according to claim 1, wherein an instruction is given to a pressure adjustment unit to correct the magnification.

[3] The first pressure adjustment amount is an amount in the lens barrel required to make the magnification of the lens system equal to the magnification at the reference atmospheric pressure under the condition that the fluctuation amount of the atmospheric pressure is zero. Pressure adjustment amount,

When the atmospheric pressure fluctuation amount is not zero, the second pressure adjustment amount is required in the lens barrel together with the first pressure adjustment amount in order to obtain the same magnification as when the atmospheric pressure fluctuation amount is zero. 3. The exposure apparatus according to claim 2, wherein the pressure adjustment amount of

[4] A first stage adjustment table composed of a pair of the first stage moving amount and the atmospheric pressure, And a second stage adjustment table configured by a pair of the second stage movement amount and the atmospheric pressure fluctuation amount per unit time.

The control unit obtains the first stage adjustment table force for the first stage movement amount corresponding to the captured atmospheric pressure, and the second stage movement corresponding to the calculated atmospheric pressure fluctuation amount. The 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:

[5] 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 stage movement amount is an ascending / descending amount of the stage that is necessary together with the first stage movement amount in order to make the focus shift zero when the atmospheric pressure fluctuation amount is not zero. 4. The exposure apparatus according to 4.

[6] The claim, wherein, when the calculated atmospheric pressure fluctuation amount exceeds a predetermined upper limit value, the control unit stops receiving the substrate to be exposed next. The exposure apparatus according to 1.

7. The exposure apparatus according to claim 1, wherein the control unit issues an alarm when the calculated atmospheric pressure fluctuation amount exceeds a predetermined upper limit value.

[8] The exposure apparatus according to [1], wherein the magnification correction and the defocus correction timing can be arbitrarily set.

[9] A step of calculating the atmospheric pressure fluctuation amount per unit time by taking the output value of the barometer at a predetermined sampling period;

A correction step of correcting a change in the optical characteristics of the lens system due to atmospheric pressure fluctuation, the correction step,

Based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure, the pressure in the lens barrel that is sealed inside is adjusted, and the magnification of the lens system housed in the lens barrel is adjusted. Step to correct,

Alternatively, based on the calculated atmospheric pressure fluctuation amount and the captured atmospheric pressure, A correction method for an exposure apparatus, comprising the step of: correcting a defocus of the lens system by moving a stage on which a plate is placed up and down.

[10] The step of correcting the magnification includes:

Referring to a first pressure adjustment table configured by a pair of a first pressure adjustment amount and an atmospheric pressure, the first pressure adjustment amount corresponding to the taken-in atmospheric pressure is set as the first pressure adjustment table. The steps to get from

The second pressure adjustment table corresponding to the calculated atmospheric pressure fluctuation amount is referenced with reference to the second pressure adjustment table composed of a pair of the second pressure adjustment amount and the atmospheric pressure fluctuation amount per unit time. Obtaining an adjustment amount of the second pressure adjustment table force;

10. The exposure apparatus correction according to claim 9, further comprising a step of adjusting the pressure in the lens barrel by a sum of the acquired first pressure adjustment amount and second pressure adjustment amount. Method.

[11] The first pressure adjustment amount is an 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 fluctuation amount of the atmospheric pressure is zero. Pressure adjustment amount,

When the atmospheric pressure fluctuation amount is not zero, the second pressure adjustment amount is required in the lens barrel together with the first pressure adjustment amount in order to obtain the same magnification as when the atmospheric pressure fluctuation amount is zero. The exposure apparatus correction method according to claim 10, wherein the pressure adjustment amount is

12. The exposure apparatus 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. Correction method.

[13] The step of correcting the defocusing includes:

Referring to the first stage adjustment table composed of a pair of the first stage movement amount and the atmospheric pressure, the first stage adjustment is performed for the first stage movement amount corresponding to the captured atmospheric pressure. Steps to get from the table;

Referring to the second stage adjustment table configured by a pair of the second stage moving amount and the atmospheric pressure fluctuation amount per unit time, the second stage adjustment table corresponding to the calculated atmospheric pressure fluctuation amount is referred to. Acquiring the stage movement amount from the second stage adjustment table, and raising and lowering the stage by the sum of the acquired first stage movement amount and the second stage movement amount. The exposure apparatus correction method according to claim 9, wherein:

[14] The first stage moving amount is an amount by which the stage is moved up and down necessary to make the lens system defocused to zero under the condition that the atmospheric pressure fluctuation amount is zero. The amount of stage movement is

14. The amount of movement of the stage is necessary together with the amount of movement of the first stage in order to reduce the defocusing to zero when the amount of fluctuation in atmospheric pressure is not zero! Exposure apparatus correction method.

15. The exposure apparatus 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. Correction method.

[16] 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, the step of exposing the photoresist using the exposure apparatus, the step of developing the photoresist to form a resist pattern after the exposure, and etching the film using the resist pattern as a mask And a step of using the film left unetched as a device pattern;

Removing the resist pattern,

The step of correcting the change in the optical characteristics of the exposure apparatus includes:

By taking the output value of the barometer at a predetermined sampling period and calculating the amount of atmospheric pressure fluctuation per unit time,

Based on the calculated atmospheric pressure fluctuation amount and the taken-in atmospheric pressure, the pressure in the lens barrel that is sealed inside is adjusted to correct the magnification of the lens system housed in the lens barrel. Or, 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. The manufacturing method of the electronic device characterized by the above-mentioned.

[17] The correction of the magnification is

Referring to a first pressure adjustment table composed of a pair of a first pressure adjustment amount and atmospheric pressure, a first pressure adjustment amount corresponding to the taken-in atmospheric pressure is determined as the first pressure adjustment table. From one bull,

The second pressure 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 adjustment amount is obtained from the second pressure adjustment table;

17. The electronic device manufacturing method according to claim 16, wherein the electronic device is manufactured by adjusting the pressure in the lens barrel by a sum of the acquired first pressure adjustment amount and second pressure adjustment amount. Manufacturing method.

[18] The defocus correction is

Referring to the first stage adjustment table configured by a pair of the first stage movement amount and the atmospheric pressure, the first stage adjustment is performed by adjusting the first stage movement amount corresponding to the captured atmospheric pressure. From the table,

The second stage movement corresponding to the calculated atmospheric pressure fluctuation amount with reference to the second stage adjustment table configured by 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;

17. The method of manufacturing an electronic device according to claim 16, wherein the method is performed by raising and lowering the stage by the sum of the acquired first stage movement amount and second stage movement amount.